Autism Clinical Presentation
- Author: James Robert Brasic, MD, MPH; Chief Editor: Caroly Pataki, MD more...
Behavioral and developmental features that suggest autism include the following:
Absence of protodeclarative pointing
Abnormal reactions to environmental stimuli
Abnormal social interactions
Absence of symbolic play
Repetitive and stereotyped behavior
Between 13% and 48% of people with autism have apparently normal development until age 15-30 months, when they lose verbal and nonverbal communication skills. These individuals may have an innate vulnerability to develop autism. Although regression may be precipitated by an environmental event (eg, immune or toxic exposures), more likely it is coincidental with other environmental events.
Protodeclarative pointing is the use of the index finger to indicate an item of interest to another person. Toddlers typically learn to use protodeclarative pointing to communicate their concern for an object to others. The absence of this behavior is predictive of a later diagnosis of autism.[89, 90]
The presence of protodeclarative pointing can be assessed by interview of the parent or caregiver. Screening questions include "Does your child ever use his or her index finger to point, to indicate interest in something?" A negative response to this question suggests the need for a specialized assessment for possible pervasive developmental disorder.
In contrast to toddlers with delayed or normal development, toddlers with autism spectrum disorder are much more interested in geometric patterns. Toddlers who prefer dynamic geometric patterns to participating in physical activities such as dance merit referral for evaluation for possible autism spectrum disorder.
Parents of children with autism report unusual responses to environmental stimuli, including excessive reaction or an unexpected lack of reaction to sensory input. Certain sounds (eg, vacuum cleaners or motorcycles) may elicit incessant screaming. Playing a radio, stereo, or television at a loud level may appear to produce hyperacusis, a condition in which ordinary sounds produce excessive auditory stimulation of a painful magnitude. Sometimes parents must rearrange the family routine so that the child is absent during noisy housekeeping activities.
Children with autistic disorder may also display exaggerated responses or rage to everyday sensory stimuli, such as bright lights or touching.
Individuals with autism may display a lack of appropriate interaction with family members. Moreover, difficulties in social interactions are common. Children may have problems making friends and understanding the social intentions of other children and may instead show attachments to objects not normally considered child oriented. Although children with autistic disorder may want to have friendships with other children, their actions may actually drive away these potential companions. They may also exhibit inappropriate friendliness and lack of awareness of personal space.
Isolation likely increases in adolescence and young adulthood. Interviews with a representative sample of 725 youths with autism (mean age 19.2 y) determined that the majority had not in the preceding year gotten together with friends or even spoken with a friend on the telephone.
High pain threshold
An absence of typical responses to pain and physical injury may also be noted. Rather than crying and running to a parent when cut or bruised, the child may display no change in behavior. Sometimes, parents do not realize that a child with autistic disorder is hurt until they observe the lesion. Parents often report that they need to ask the child if something is wrong when the child's mood changes, and may need to examine the child's body to detect injury.
Speech abnormalities are common. They take the form of language delays and deviations. Pronominal reversals are common, including saying "you" instead of "I." Some speech habits, such as repeating words and sentences after someone else says them, using language only the child understands, or saying things whose meaning is not clear, may occur not only in autism but in other disorders as well.
Baron-Cohen and colleagues demonstrated that the absence of symbolic play in infants and toddlers is highly predictive of a later diagnosis of autism.[89, 90] Therefore, screening for the presence of symbolic play is a key component of the routine assessment of well babies. The absence of normal pretend play indicates the need for referral for specialized developmental assessment for autism and other developmental disabilities.
Odd play may take the form of interest in parts of objects instead of functional uses of the whole object. For example, a child with autistic disorder may enjoy repeatedly spinning a wheel of a car instead of moving the entire car on the ground in a functional manner. The nonfunctional play of a boy with autism is illustrated in the video files below. Please note that videos represent a diagnostic assessment of a child. The child is allowed to exhibit the abnormal behaviors to demonstrate those items on a video for confirmation by blind raters. If the child exhibited behaviors danger to himself, such as self-injurious behaviors, or dangerous to other, such as attacking others, then the examiner would intervene to prevent injury to the child and others. The videos do not in any way represent treatment for the disorder. (The second and third videos also demonstrate an aforementioned trait, the lack of appropriate interaction with family members.)
Children with autistic disorder may enjoy repeatedly lining up objects or dropping objects from a particular height. They may also be fascinated with items that are not typical toys, such as pieces of string, and may enjoy hoarding rubber bands, paper clips, and pieces of paper. In addition, children with autistic disorder may spend hours watching traffic lights, fans, and running water. Some parents report that they must lock the bathroom door to prevent the child from flushing the toilet all day long.
Response to febrile illnesses
Children with autism may be particularly vulnerable to develop infections and febrile illnesses due to immunologic problems. By seeking pediatric intervention promptly at the onset of infections and febrile illnesses, parents may be able to abort sequelae of chronic infections.
During a febrile illness, children with autistic disorder may show a decrease in behavioral abnormalities that plague the parents when the child is well (eg, self-injurious behaviors, aggression toward others, property destruction, temper tantrums, hyperactivity).
This inhibition of negative behaviors may occur with various febrile illnesses, including ear infections, upper respiratory tract infections, and childhood illnesses. (A parent may say, "When he is suddenly an angel, I know that he has an ear infection.") The recovery of the child from the febrile illness may be accompanied by an abrupt return of the child's usual problematic behaviors.
Autism Screening Checklist
Having parents fill out the Autism Screening Checklist can identify children who merit further assessment for possible autism. See the image below for a printable version of the checklist.
The significance of answers to individual Autism Screening Checklist items is as follows:
Item 1- A "yes" occurs in healthy children and children with some pervasive developmental disorders; a "no" occurs in children with autism, Rett syndrome, and other developmental disorders
Item 2 - A "yes" occurs in healthy children, not children with autism
Item 3 - A "yes" occurs in healthy children and children with Asperger syndrome (ie, high-functioning autism); a "no" occurs in children with Rett syndrome; children with autism may elicit a “yes” or a "no"; some children with autism never speak; some children with autism may develop speech normally and then experience a regression with the loss of speech
Item 4 - A "yes" occurs in healthy children and children with Asperger syndrome or some other pervasive developmental disorders; a "no" occurs in children with developmental disorders; children with autism may elicit a "yes" or a "no"
Items 5-10 - Scores of "yes" occur in some children with autism and in children with other pervasive developmental disorders
Item 11 – A "yes" occurs in healthy children; a "no" occurs in some children with autism and in children with other pervasive developmental disorders
Items 12, 13 - Scores of "yes" occur in some children with autism and in children with other pervasive developmental disorders
Items 14-19 - Scores of "yes" occur in children with schizophrenia and other disorders, not in children with autism, Asperger syndrome, or other autism spectrum disorders
The higher the total score for items 5-10, 12, and 13 on the Autism screening checklist, the more likely that an autism spectrum disorder is present.
Screening well babies for signs predictive of autistic disorder is important. Baron-Cohen and colleagues observed that abnormalities in pretend play, gaze monitoring, and protodeclarative pointing noted in toddlers during well-child visits in the United Kingdom were useful in predicting the later diagnosis of autistic disorder.[89, 90]
Baron-Cohen and colleagues developed a set of valid and reliable tools to screen for autism spectrum disorders over the lifespan, including the Checklist for Autism in Toddlers (CHAT) and its revisions, the Modified CHAT (MCHAT) and the Quantitative CHAT (QCHAT), for newborns and toddlers,[89, 90, 95] as well as the Autism-Spectrum Quotient (AQ), for children, adolescents, and adults. The possible cultural limitations of these tools in different ethnic groups in various geographic regions remain to be demonstrated.
In screening for the presence of symbolic play, other make-believe play may be substituted based on cultural relevance. The child should respond appropriately to a pretend activity compared with most other children of the same culture.
The assessment of normal gaze monitoring, suggested by Baron-Cohen and colleagues, consists of the following steps: (1) the clinician calls the child's name, points to a toy on the other side of the room, and says, "Oh look! There's a [name a toy]!";[89, 90] (2) if the child looks across the room to see the item indicated by the clinician, then a joint attention is established, indicating normal gaze monitoring.
Baron-Cohen and colleagues established the following protocol to assess for the presence of protodeclarative pointing:
Say to the child, “Where's the light?” or “Show me the light”
A normal response is for the child to point with his or her index finger at the light while looking up at the clinician's face [89, 90]
If the child does not respond appropriately, the procedure may be repeated with a teddy bear or any other unreachable object
Clumsiness, awkward walk, and abnormal motor movements are characteristic features of autistic disorder. Manifestations of attention deficit hyperactivity disorder that are very often associated with autistic disorder include hyperkinesis and stereotypies.
Common abnormal motor movements in children with autism include hand flapping, in which the upper extremity is rapidly raised and lowered with a flaccid wrist so that the hand flaps like a flag in the wind. Hand flapping typically occurs when the child is happy or excited. It may occur in combination with movement of the entire body, such as bouncing (ie, jumping up and down) and rotating (ie, constantly spinning around a vertical axis in the midline of the body).
Children with autistic disorder also often display motor tics and are unable to remain still. Because children with autistic disorder are often mentally retarded and nonverbal, expressing subjective experiences associated with the movement is often impossible for them. Thus, the diagnosis of akathisia cannot be applied in these cases, because this diagnosis requires the verbalization of a sensation of inner restlessness and an urge to move.
Head and hand features
Aberrant palmar creases and other dermatoglyphic anomalies are more common in children with autistic disorder.
Although the head circumference of children with autism may be small at birth, many children with autism experience a rapid increase in the rate of growth from age 6 months to 2 years. The head circumference is increased in a subgroup of approximately one fifth of the population of children with autistic disorder without known comorbid conditions. Increased head circumference is more common in boys and is associated with poor adaptive behavior. The head circumference may return to normal in adolescence.
Patients with autistic disorder merit a careful assessment of movements. The caregiver and clinicians may be asked whether the patient shows any unusual motions in the mouth, face, hands, or feet and, if so, may be asked to describe them and how they bother the patient.
The patient may be asked to sit on the chair with legs slightly apart, feet flat on the floor, and hands hanging supported between the legs or hanging over the knees. The patient may be asked to open his or her mouth and then twice to stick out the tongue.
If the subject does not perform the requested action, the examiner then repeatedly performs the actions in the direct view of the subject to demonstrate the desired actions.
The patient may be asked to sit, stand, and lie on a sheet on the floor for 2 minutes in each position and to remain motionless while in each posture. In each position, the patient is asked, "Do you have a sensation of inner restlessness?" and "Do you have the urge to move?" These questions require an appropriate developmental level for a useful response. Therefore, most children with autism cannot respond appropriately.
In the absence of a clear verbal response, the subjective items are not rated. Nevertheless, the objective behavior of the child can be observed and rated.
Movements observed in individuals with autistic disorder are frequently classified as stereotypies (eg, purposeless, repetitive, patterned motions, postures, and sounds). Stereotypies are divided into the following 3 topologic classes:
Orofacial - Eg, tongue, mouth, and facial movements; smelling; and sniffing and other sounds
Extremity - Eg, hand, finger, toe, and leg
Head and trunk - Eg, rolling, tilting, or banging of the head, and rocking of the body
Stereotypies occur in infants who are not autistic and in children with mental retardation. Regular assessment of stereotypies is a valuable practice because stereotypies may bother other people and interfere with performance at school, work, and home. Routine assessment of stereotypies before, during, and after treatment is valuable in determining the effects of interventions.
Stereotypies are assessed for clinical purposes through regular use of the Timed Stereotypies Rating Scale. For this procedure, the occurrence of stereotypies is noted during 30-second intervals over a 10-minute period. For additional information about the rating of stereotypies, please see Tardive Dyskinesia.
A particularly serious form of stereotypy is self-injurious behavior. Self-injury may take any of the following forms:
Picking at the skin
Head punching and slapping
Head-to-object and body-to-object banging
Body punching and slapping
Poking the eye, the anus, and other body parts
Removal of hair and nails
Self-injury can result in morbidity and mortality. For example, eye poking and head banging may cause retinal detachments resulting in blindness. Although only a minority of the population of children with autism manifest self-injury, they constitute some of the most challenging patients in developmental pediatrics.
Children with autism and related conditions may persist incessantly with repetitive behaviors that annoy others, despite instructions to cease. Children with autism spectrum disorder typically do not respond to spanking and other forms of traditional discipline. Parents, teachers, and others may eventually lose control and inflict physical injury on the child.
For this reason, children with autism spectrum disorder are at high risk for physical abuse; in addition, when physical abuse occurs, these children may not report it. Therefore, pediatricians and other healthcare providers must maintain a high level of suspicion for the possibility of physical abuse when assessing children with autism spectrum disorders and must conduct regular, careful physical examinations.
Unlike many other children with mental retardation, children with autistic disorder are typically physically normal in appearance, without dysmorphic features. They may be beautiful children and, thus, may attract the interest of those who are sexually aroused by children. Children with autism spectrum disorder may lack ability to communicate inappropriate sexual contact to responsible authorities.
Thus, parents, teachers, health-care providers, and others must maintain a high level of suspicion for the possibility of sexual abuse when assessing children with autism spectrum disorder. On physical examination, external examination of genitalia is appropriate. If bruises and other evidence of trauma are present, then pelvic and rectal examinations may be indicated.
Examination of siblings
Siblings of children with autism are at risk for developing traits of autism and even a full-blown diagnosis of autism. A tenth of the siblings of children with autism meet the diagnostic criteria for an autism spectrum disorder. An additional fifth of siblings of children with autism have delayed development of language. Screening should be performed not only for autism-related symptoms but also for language delays, learning difficulties, social problems, and anxiety or depressive symptoms.
[Guideline] Filipek PA, et al. Practice parameter: screening and diagnosis of autism: report of the Quality Standards Subcommittee of the American Academy of Neurology and the Child Neurology Society. Neurology 2000 Aug;55(4):468-79. Reaffirmed July 2010. [Full Text].
Courchesne E, Carper R, Akshoomoff N. Evidence of brain overgrowth in the first year of life in autism. JAMA. 2003 Jul 16. 290(3):337-44. [Medline].
Aylward EH, Minshew NJ, Field K, Sparks BF, Singh N. Effects of age on brain volume and head circumference in autism. Neurology. 2002 Jul 23. 59(2):175-83. [Medline].
American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders (DSM-V). 5th Edition. Washington, DC: American Psychiatric Association; 2013:
Antshel KM, Polacek C, McMahon M, Dygert K, Spenceley L, Dygert L, et al. Comorbid ADHD and anxiety affect social skills group intervention treatment efficacy in children with autism spectrum disorders. J Dev Behav Pediatr. 2011 Jul-Aug. 32(6):439-46. [Medline].
Marshall BL, Napolitano DA, McAdam DB, Dunleavy III JJ, Tessing JL, Varrell J. Venlafaxine and increased aggression in a female with autism. J Am Acad Child Adolesc Psychiatry. 2003 Apr. 42(4):383-4. [Medline].
Teitelbaum P, Teitelbaum O, Nye J, Fryman J, Maurer RG. Movement analysis in infancy may be useful for early diagnosis of autism. Proc Natl Acad Sci U S A. 1998 Nov 10. 95(23):13982-7. [Medline]. [Full Text].
Brasic JR, Holland JA. Reliable classification of case-control studies of autistic disorder and obstetric complications. Journal of Developmental and Physical Disabilities. 2006;18:355-381:
Brasic JR, Holland JA. A qualitative and quantitative review of obstetric complications and autistic disorder. Journal of Developmental and Physical Disabilities. 2007;19:337-364:
Brasic JR, Holland JA, Alexander M. The increased likelihood of obstetric complications in autistic disorder [abstract]. Southern Medical Journal. 2003;96 (10 supplement):S34:
Fatemi SH, Earle J, Kanodia R, Kist D, Emamian ES, Patterson PH, et al. Prenatal viral infection leads to pyramidal cell atrophy and macrocephaly in adulthood: implications for genesis of autism and schizophrenia. Cell Mol Neurobiol. 2002 Feb. 22(1):25-33. [Medline].
Gutierrez GC, Smalley SL, Tanguay PE. Autism in tuberous sclerosis complex. J Autism Dev Disord. 1998 Apr. 28(2):97-103. [Medline].
Court finds no Vaccines-autism link. Hum Vaccin. 2010 May 14. 6(5):[Medline].
Brauser D. No Evidence Multiple Vaccines Raise Autism Risk, CDC Says. Medscape Medical News. Available at http://www.medscape.com/viewarticle/781670. Accessed: April 3, 2013.
DeStefano F, Price CS, Weintraub ES. Increasing Exposure to Antibody-Stimulating Proteins and Polysaccharides in Vaccines Is Not Associated with Risk of Autism. J Peds. March 2013.
Hammer LD, Curry ES, Harlor AD, Laughlin JJ, Leeds AJ, Lessin HR, et al. Increasing immunization coverage. Pediatrics. 2010 Jun. 125(6):1295-304. [Medline].
Filipek PA, Accardo PJ, Ashwal S, Baranek GT, Cook EH Jr, Dawson G, et al. Practice parameter: screening and diagnosis of autism: report of the Quality Standards Subcommittee of the American Academy of Neurology and the Child Neurology Society. Neurology. 2000 Aug 22. 55(4):468-79. [Medline].
Brauser D. New Practice Guidelines for Autism. Medscape Medical News. Available at http://www.medscape.com/viewarticle/819935. Accessed: February 4, 2014.
Volkmar F, Siegel M, Woodbury-Smith M, King B, McCracken J, State M. Practice parameter for the assessment and treatment of children and adolescents with autism spectrum disorder. J Am Acad Child Adolesc Psychiatry. 2014 Feb. 53(2):237-57. [Medline].
Courchesne E, Mouton PR, Calhoun ME, Semendeferi K, Ahrens-Barbeau C, Hallet MJ, et al. Neuron number and size in prefrontal cortex of children with autism. JAMA. 2011 Nov 9. 306(18):2001-10. [Medline].
Davenport L. Measuring thoughts' accurately detects autism. Medscape Medical News. December 3, 2014. [Full Text].
Just MA, Cherkassky VL, Buchweitz A, Keller TA, Mitchell TM. Identifying autism from neural representations of social interactions: neurocognitive markers of autism. PLoS One. 2014. 9(12):e113879. [Medline]. [Full Text].
Hughes JR. Autism: the first firm finding = underconnectivity?. Epilepsy Behav. 2007 Aug. 11(1):20-4. [Medline].
Ecker C, Suckling J, Deoni SC, Lombardo MV, Bullmore ET, Baron-Cohen S, et al. Brain anatomy and its relationship to behavior in adults with autism spectrum disorder: a multicenter magnetic resonance imaging study. Arch Gen Psychiatry. 2012 Feb. 69(2):195-209. [Medline].
Brasic JR, Mohamed M. Human brain imaging of autism spectrum disorders. In: Seeman P, Madras B, Eds. Imaging of the Human Brain in Health and Disease. Neuroscience-Net, LLC, 2012. [Full Text].
NIH press release. Disorganized cortical patches suggest prenatal origin of autism. Available at http://www.nih.gov/news/health/mar2014/nimh-27.htm. Accessed: April 1, 2014.
Stoner R, Chow ML, Boyle MP, Sunkin SM, Mouton PR, Roy S, et al. Patches of disorganization in the neocortex of children with autism. N Engl J Med. 2014 Mar 27. 370(13):1209-19. [Medline].
Carmody DP, Lewis M. Regional white matter development in children with autism spectrum disorders. Dev Psychobiol. 2010 Dec. 52(8):755-63. [Medline].
Cauda F, Geda E, Sacco K, D'Agata F, Duca S, Geminiani G, et al. Grey matter abnormality in autism spectrum disorder: an activation likelihood estimation meta-analysis study. J Neurol Neurosurg Psychiatry. 2011 Dec. 82(12):1304-13. [Medline].
Chugani DC. Neuroimaging and neurochemistry of autism. Pediatr Clin North Am. 2012 Feb. 59(1):63-73, x. [Medline].
Pennesi CM, Klein LC. Effectiveness of the gluten-free, casein-free diet for children diagnosed with autism spectrum disorder: based on parental report. Nutr Neurosci. 2012 Mar. 15(2):85-91. [Medline].
Alberti A, Pirrone P, Elia M, Waring RH, Romano C. Sulphation deficit in "low-functioning" autistic children: a pilot study. Biol Psychiatry. 1999 Aug 1. 46(3):420-4. [Medline].
James SJ, Melnyk S, Jernigan S, Cleves MA, Halsted CH, Wong DH, et al. Metabolic endophenotype and related genotypes are associated with oxidative stress in children with autism. Am J Med Genet B Neuropsychiatr Genet. 2006 Dec 5. 141B(8):947-56. [Medline]. [Full Text].
Oliveira G, Diogo L, Grazina M, Garcia P, Ataíde A, Marques C, et al. Mitochondrial dysfunction in autism spectrum disorders: a population-based study. Dev Med Child Neurol. 2005 Mar. 47(3):185-9. [Medline].
Filipek PA, Juranek J, Nguyen MT, Cummings C, Gargus JJ. Relative carnitine deficiency in autism. J Autism Dev Disord. 2004 Dec. 34(6):615-23. [Medline].
Larsson HJ, Eaton WW, Madsen KM, Vestergaard M, Olesen AV, Agerbo E, et al. Risk factors for autism: perinatal factors, parental psychiatric history, and socioeconomic status. Am J Epidemiol. 2005 May 15. 161(10):916-25; discussion 926-8. [Medline].
Lawler CP, Croen LA, Grether JK, Van de Water J. Identifying environmental contributions to autism: provocative clues and false leads. Ment Retard Dev Disabil Res Rev. 2004. 10(4):292-302. [Medline].
Glasson EJ, Bower C, Petterson B, de Klerk N, Chaney G, Hallmayer JF. Perinatal factors and the development of autism: a population study. Arch Gen Psychiatry. 2004 Jun. 61(6):618-27. [Medline].
Hughes S. Prenatal Valproate Exposure Linked to Autism. Medscape Medical News. Available at http://www.medscape.com/viewarticle/803034. Accessed: May 2, 2013.
Christensen J, Grønborg TK, Sørensen MJ, Schendel D, Parner ET, Pedersen LH, et al. Prenatal valproate exposure and risk of autism spectrum disorders and childhood autism. JAMA. 2013 Apr 24. 309(16):1696-703. [Medline].
Croen LA, Grether JK, Yoshida CK, Odouli R, Hendrick V. Antidepressant use during pregnancy and childhood autism spectrum disorders. Arch Gen Psychiatry. 2011 Nov. 68(11):1104-12. [Medline].
Brooks M. Autism Risk Linked to Maternal Thyroid Dysfunction. Available at http://www.medscape.com/viewarticle/809718. Accessed: August 27, 2013.
Román GC, Ghassabian A, Bongers-Schokking JJ, Jaddoe VW, Hofman A, de Rijke YB, et al. Association of gestational maternal hypothyroxinemia and increased autism risk. Ann Neurol. 2013 Aug 13. [Medline].
Ozonoff S, Young GS, Carter A, Messinger D, Yirmiya N, Zwaigenbaum L, et al. Recurrence risk for autism spectrum disorders: a Baby Siblings Research Consortium study. Pediatrics. 2011 Sep. 128(3):e488-95. [Medline]. [Full Text].
Abrahams BS, Geschwind DH. Connecting genes to brain in the autism spectrum disorders. Arch Neurol. 2010 Apr. 67(4):395-9. [Medline].
Hallmayer J, Cleveland S, Torres A, Phillips J, Cohen B, Torigoe T, et al. Genetic heritability and shared environmental factors among twin pairs with autism. Arch Gen Psychiatry. 2011 Nov. 68(11):1095-102. [Medline].
Gillberg C, Cederlund M. Asperger syndrome: familial and pre- and perinatal factors. J Autism Dev Disord. 2005 Apr. 35(2):159-66. [Medline].
Merritt JL 2nd, Jalal SM, Barbaresi WJ, Babovic-Vuksanovic D. 14q32.3 deletion syndrome with autism. Am J Med Genet A. 2005 Feb 15. 133A(1):99-100. [Medline].
Liu XQ, Georgiades S, Duku E, Thompson A, Devlin B, Cook EH, et al. Identification of genetic loci underlying the phenotypic constructs of autism spectrum disorders. J Am Acad Child Adolesc Psychiatry. 2011 Jul. 50(7):687-696.e13. [Medline].
Schaefer GB, Lutz RE. Diagnostic yield in the clinical genetic evaluation of autism spectrum disorders. Genet Med. 2006 Sep. 8(9):549-56. [Medline].
Durand CM, Betancur C, Boeckers TM, Bockmann J, Chaste P, Fauchereau F, et al. Mutations in the gene encoding the synaptic scaffolding protein SHANK3 are associated with autism spectrum disorders. Nat Genet. 2007 Jan. 39(1):25-7. [Medline]. [Full Text].
Garber KB, Visootsak J, Warren ST. Fragile X syndrome. Eur J Hum Genet. 2008 Jun. 16(6):666-72. [Medline].
Nakamoto M, Nalavadi V, Epstein MP, Narayanan U, Bassell GJ, Warren ST. Fragile X mental retardation protein deficiency leads to excessive mGluR5-dependent internalization of AMPA receptors. Proc Natl Acad Sci U S A. 2007 Sep 25. 104(39):15537-42. [Medline]. [Full Text].
Curatolo P, Porfirio MC, Benedetti S, Giana G, Manzi B. [Autismo.]. Minerva Pediatr. 2008/10;60(5):846-848:
Curatolo P, Bombardieri R, Jozwiak S. Tuberous sclerosis. Lancet. 2008 Aug 23. 372(9639):657-68. [Medline].
Roberts EM, English PB, Grether JK, Windham GC, Somberg L, Wolff C. Maternal residence near agricultural pesticide applications and autism spectrum disorders among children in the California Central Valley. Environ Health Perspect. 2007 Oct. 115(10):1482-9. [Medline]. [Full Text].
Samson K. CDC-backed study suggests possible link between autistic disorders, maternal perticide exposure in California. Neurology Today. September 2007;7:7:
Hackethal V. More Evidence Links Autism to Air Pollution. Medscape Medical News. Available at http://www.medscape.com/viewarticle/833653. Accessed: October 24, 2014.
Evelyn Talbott, Lynne Marshall, Judith Rager, Vincent Arena, Ravi Sharma. The Association of National Air Toxics Assessment Exposures and the Risk of Childhood Autism Spectrum Disorder: A Case Control Study. American Association for Aerosol Research. Available at http://aaarabstracts.com/2014/viewabstract.php?pid=599. Accessed: October 24, 2014.
Sandin S, Hultman CM, Kolevzon A, Gross R, MacCabe JH, Reichenberg A. Advancing maternal age is associated with increasing risk for autism: a review and meta-analysis. J Am Acad Child Adolesc Psychiatry. 2012 May. 51(5):477-486.e1. [Medline].
Hultman CM, Sandin S, Levine SZ, Lichtenstein P, Reichenberg A. Advancing paternal age and risk of autism: new evidence from a population-based study and a meta-analysis of epidemiological studies. Mol Psychiatry. 2011 Dec. 16(12):1203-12. [Medline].
Rapin I, Tuchman RF. What is new in autism?. Curr Opin Neurol. 2008 Apr. 21(2):143-9. [Medline].
Honda H, Shimizu Y, Rutter M. No effect of MMR withdrawal on the incidence of autism: a total population study. J Child Psychol Psychiatry. 2005 Jun. 46(6):572-9. [Medline].
Taylor B, Miller E, Farrington CP, Petropoulos MC, Favot-Mayaud I, Li J, et al. Autism and measles, mumps, and rubella vaccine: no epidemiological evidence for a causal association. Lancet. 1999 Jun 12. 353(9169):2026-9. [Medline].
Thompson WW, Price C, Goodson B, Shay DK, Benson P, Hinrichsen VL, et al. Early thimerosal exposure and neuropsychological outcomes at 7 to 10 years. N Engl J Med. 2007 Sep 27. 357(13):1281-92. [Medline].
Retraction--Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children. Lancet. 2010 Feb 6. 375(9713):445. [Medline].
Dobbs M. What the autism studies show isn't reflected in what the candidates say. The Washington Post. April 22, 2008;A: A8:
Newschaffer CJ, Falb MD, Gurney JG. National autism prevalence trends from United States special education data. Pediatrics. 2005 Mar. 115(3):e277-82. [Medline].
Barbaresi WJ, Katusic SK, Colligan RC, Weaver AL, Jacobsen SJ. The incidence of autism in Olmsted County, Minnesota, 1976-1997: results from a population-based study. Arch Pediatr Adolesc Med. 2005 Jan. 159(1):37-44. [Medline].
Rutter M. Aetiology of autism: findings and questions. J Intellect Disabil Res. 2005 Apr. 49:231-8. [Medline].
Rutter M. Incidence of autism spectrum disorders: changes over time and their meaning. Acta Paediatr. 2005 Jan. 94(1):2-15. [Medline].
Developmental Disabilities Monitoring Network Surveillance Year 2010 Principal Investigators, Centers for Disease Control and Prevention (CDC). Prevalence of autism spectrum disorder among children aged 8 years - autism and developmental disabilities monitoring network, 11 sites, United States, 2010. MMWR Surveill Summ. 2014 Mar 28. 63 (2):1-21. [Medline].
Kim YS, Leventhal BL, Koh YJ, Fombonne E, Laska E, Lim EC, et al. Prevalence of autism spectrum disorders in a total population sample. Am J Psychiatry. 2011 Sep. 168(9):904-12. [Medline].
Kurita H. [Current status of autism studies]. Seishin Shinkeigaku Zasshi. 2001. 103(1):64-75. [Medline].
Bailey A, Bolton P, Butler L, Le Couteur A, Murphy M, Scott S, et al. Prevalence of the fragile X anomaly amongst autistic twins and singletons. J Child Psychol Psychiatry. 1993 Jul. 34(5):673-88. [Medline].
Chudley AE, Hagerman RJ. Fragile X syndrome. J Pediatr. 1987 Jun. 110(6):821-31. [Medline].
Cohen IL, Sudhalter V, Pfadt A, Jenkins EC, Brown WT, Vietze PM. Why are autism and the fragile-X syndrome associated? Conceptual and methodological issues. Am J Hum Genet. 1991 Feb. 48(2):195-202. [Medline]. [Full Text].
Einfeld SL. Autism and the fragile X syndrome. Am J Med Genet. 1988 May-Jun. 30(1-2):237-8. [Medline].
Fisch GS, Cohen IL, Jenkins EC, Brown WT. Screening developmentally disabled male populations for fragile X: the effect of sample size. Am J Med Genet. 1988 May-Jun. 30(1-2):655-63. [Medline].
Reiss AL, Freund L. Fragile X syndrome, DSM-III-R, and autism. J Am Acad Child Adolesc Psychiatry. 1990 Nov. 29(6):885-91. [Medline].
Wang LW, Tancredi DJ, Thomas DW. The prevalence of gastrointestinal problems in children across the United States with autism spectrum disorders from families with multiple affected members. J Dev Behav Pediatr. 2011 Jun. 32(5):351-60. [Medline].
Mahoney A, Poling A. Sexual Abuse Prevention for People with Severe Developmental Disabilities. J of Developmental and Physical Disabilities. May 2011;23(4):369-76:
Anderson C, Law JK, Daniels A, Rice C, Mandell DS, Hagopian L, et al. Occurrence and family impact of elopement in children with autism spectrum disorders. Pediatrics. 2012 Nov. 130(5):870-7. [Medline].
Baron-Cohen S, Allen J, Gillberg C. Can autism be detected at 18 months? The needle, the haystack, and the CHAT. Br J Psychiatry. Dec 1992;161:839-43:[Medline].
Baron-Cohen S, Cox A, Baird G, Swettenham J, Nightingale N, Morgan K, et al. Psychological markers in the detection of autism in infancy in a large population. Br J Psychiatry. 1996 Feb. 168(2):158-63. [Medline].
Lee MS, Kim JI, Ernst E. Massage therapy for children with autism spectrum disorders: a systematic review. J Clin Psychiatry. 2011 Mar. 72(3):406-11. [Medline].
Lord C, Rutter M, Le Couteur A. Autism Diagnostic Interview-Revised: a revised version of a diagnostic interview for caregivers of individuals with possible pervasive developmental disorders. J Autism Dev Disord. 1994 Oct. 24(5):659-85. [Medline].
Liptak GS, Kennedy JA, Dosa NP. Social Participation in a Nationally Representative Sample of Older Youth and Young Adults With Autism. J Dev Behav Pediatr. 2011 Apr 15. [Medline].
Allison C, Auyeung B, Baron-Cohen S. Toward brief "Red Flags" for autism screening: The Short Autism Spectrum Quotient and the Short Quantitative Checklist for Autism in toddlers in 1,000 cases and 3,000 controls [corrected]. J Am Acad Child Adolesc Psychiatry. 2012 Feb. 51(2):202-212.e7. [Medline].
Allison C, Baron-Cohen S, Wheelwright S, Charman T, Richler J, Pasco G, et al. The Q-CHAT (Quantitative CHecklist for Autism in Toddlers): a normally distributed quantitative measure of autistic traits at 18-24 months of age: preliminary report. J Autism Dev Disord. 2008 Sep. 38(8):1414-25. [Medline].
Auyeung B, Baron-Cohen S, Wheelwright S, Allison C. The Autism Spectrum Quotient: Children's Version (AQ-Child). J Autism Dev Disord. 2008 Aug. 38(7):1230-40. [Medline].
Baron-Cohen S, Hoekstra RA, Knickmeyer R, Wheelwright S. The Autism-Spectrum Quotient (AQ)--adolescent version. J Autism Dev Disord. 2006 Apr. 36(3):343-50. [Medline].
Baron-Cohen S, Wheelwright S, Skinner R, Martin J, Clubley E. The autism-spectrum quotient (AQ): evidence from Asperger syndrome/high-functioning autism, males and females, scientists and mathematicians. J Autism Dev Disord. 2001 Feb. 31(1):5-17. [Medline].
Fombonne E, Rogé B, Claverie J, Courty S, Frémolle J. Microcephaly and macrocephaly in autism. J Autism Dev Disord. 1999 Apr. 29(2):113-9. [Medline].
National Center for Health Statistics. International Classification of Diseases (ICD-9-CM), 9th Revision, Clinical Modification. 4th Edition. Los Angeles, CA: Practice Management Information Corporation (PMIC); 1993:
Canal-Bedia R, García-Primo P, Martín-Cilleros MV, Santos-Borbujo J, Guisuraga-Fernández Z, Herráez-García L, et al. Modified checklist for autism in toddlers: cross-cultural adaptation and validation in Spain. J Autism Dev Disord. 2011 Oct. 41(10):1342-51. [Medline].
[Guideline] Cincinnati Children's Hospital Medical Center. Best evidence statement (BESt). Use of motor and self-care assessment tools for children with autism spectrum disorder (ASD). 2009 Jul. [Full Text].
Cincinnati Children's Hospital Medical Center. Best evidence statement (BESt). Use of sensory assessment tools with children diagnosed with autism spectrum disorder (ASD). 2009 Mar. [Full Text].
[Guideline] New York State Department of Health, Division of Family Health, Bureau of Early Intervention. Clinical Practice Guideline: Quick Reference Guide. Autism/Pervasive Developmental Disorders, Assessment and Intervention for Young Children (Age 0-3 Years). Reprinted 2009. [Full Text].
Lord C, Petkova E, Hus V, Gan W, Lu F, Martin DM, et al. A multisite study of the clinical diagnosis of different autism spectrum disorders. Arch Gen Psychiatry. 2012 Mar. 69(3):306-13. [Medline].
Sahota PK, Miles JH, Wang CH. Sleep disorders in children with autism. Neurology. 1997;48 (3):A258:
Hashimoto T, Tayama M, Miyazaki M, Murakawa K, Shimakawa S, Yoneda Y, et al. Brainstem involvement in high functioning autistic children. Acta Neurol Scand. 1993 Aug. 88(2):123-8. [Medline].
Hashimoto T, Tayama M, Murakawa K, Yoshimoto T, Miyazaki M, Harada M, et al. Development of the brainstem and cerebellum in autistic patients. J Autism Dev Disord. 1995 Feb. 25(1):1-18. [Medline].
Filipek PA. Quantitative magnetic resonance imaging in autism: the cerebellar vermis. Curr Opin Neurol. 1995 Apr. 8(2):134-8. [Medline].
Via E, Radua J, Cardoner N, Happé F, Mataix-Cols D. Meta-analysis of gray matter abnormalities in autism spectrum disorder: should Asperger disorder be subsumed under a broader umbrella of autistic spectrum disorder?. Arch Gen Psychiatry. 2011 Apr. 68(4):409-18. [Medline].
Eyler LT, Pierce K, Courchesne E. A failure of left temporal cortex to specialize for language is an early emerging and fundamental property of autism. Brain. 2012 Mar. 135:949-60. [Medline]. [Full Text].
Barnea-Goraly N, Lotspeich LJ, Reiss AL. Similar white matter aberrations in children with autism and their unaffected siblings: a diffusion tensor imaging study using tract-based spatial statistics. Arch Gen Psychiatry. 2010 Oct. 67(10):1052-60. [Medline].
Jou RJ, Mateljevic N, Kaiser MD, Sugrue DR, Volkmar FR, Pelphrey KA. Structural neural phenotype of autism: preliminary evidence from a diffusion tensor imaging study using tract-based spatial statistics. AJNR Am J Neuroradiol. 2011 Oct. 32(9):1607-13. [Medline].
Heh CW, Smith R, Wu J, Hazlett E, Russell A, Asarnow R, et al. Positron emission tomography of the cerebellum in autism. Am J Psychiatry. 1989 Feb. 146(2):242-5. [Medline].
Chiron C, Leboyer M, Leon F, Jambaqué I, Nuttin C, Syrota A. SPECT of the brain in childhood autism: evidence for a lack of normal hemispheric asymmetry. Dev Med Child Neurol. 1995 Oct. 37(10):849-60. [Medline].
McGuire K, Erickson C, Gabriels RL, Kaplan D, Mazefsky C, McGonigle J, et al. Psychiatric Hospitalization of Children With Autism or Intellectual Disability: Consensus Statements on Best Practices. J Am Acad Child Adolesc Psychiatry. 2015 Dec. 54 (12):969-71. [Medline].
[Guideline] Luiselli JK, Bass JD, Whitcomb SA. Teaching applied behavior analysis knowledge competencies to direct-care service providers: outcome assessment and social validation of a training program. Behav Modif. 2010 Sep. 34(5):403-14. [Medline].
[Guideline] Carr JE, Fox EJ. Using video technology to disseminate behavioral procedures: a review of Functional Analysis: a Guide for Understanding Challenging Behavior (DVD). J Appl Behav Anal. 2009 Winter. 42(4):919-23. [Medline]. [Full Text].
Ganz JB, Davis JL, Lund EM, Goodwyn FD, Simpson RL. Meta-analysis of PECS with individuals with ASD: investigation of targeted versus non-targeted outcomes, participant characteristics, and implementation phase. Res Dev Disabil. 2012 Mar-Apr. 33(2):406-18. [Medline].
Dawson G, Rogers S, Munson J, Smith M, Winter J, Greenson J, et al. Randomized, controlled trial of an intervention for toddlers with autism: the Early Start Denver Model. Pediatrics. 2010 Jan. 125(1):e17-23. [Medline].
Dawson G, Jones EJ, Merkle K, Venema K, Lowy R, Faja S, et al. Early behavioral intervention is associated with normalized brain activity in young children with autism. J Am Acad Child Adolesc Psychiatry. 2012 Nov. 51(11):1150-9. [Medline].
Rogers SJ, Estes A, Lord C, Vismara L, Winter J, Fitzpatrick A, et al. Effects of a Brief Early Start Denver Model (ESDM)-Based Parent Intervention on Toddlers at Risk for Autism Spectrum Disorders: A Randomized Controlled Trial. J Am Acad Child Adolesc Psychiatry. 2012 Oct. 51(10):1052-65. [Medline]. [Full Text].
Brooks M. GI Troubles Common, Linked to Negative Behaviors in Autism. Medscape Medical News. Available at http://www.medscape.com/viewarticle/814364.. Accessed: November 26, 2013.
Chaidez V, Hansen RL, Hertz-Picciotto I. Gastrointestinal Problems in Children with Autism, Developmental Delays or Typical Development. J Autism Dev Disord. 2013 Nov 6. [Medline].
Mousain-Bosc M, Roche M, Polge A, Pradal-Prat D, Rapin J, Bali JP. Improvement of neurobehavioral disorders in children supplemented with magnesium-vitamin B6. II. Pervasive developmental disorder-autism. Magnes Res. 2006 Mar. 19(1):53-62. [Medline].
Adams JB, Audhya T, McDonough-Means S, Rubin RA, Quig D, Geis E, et al. Effect of a vitamin/mineral supplement on children and adults with autism. BMC Pediatr. 2011 Dec 12. 11:111. [Medline]. [Full Text].
Oswald DP, Sonenklar NA. Medication use among children with autism spectrum disorders. J Child Adolesc Psychopharmacol. 2007 Jun. 17(3):348-55. [Medline].
Spencer D, Marshall J, Post B, Kulakodlu M, Newschaffer C, Dennen T, et al. Psychotropic medication use and polypharmacy in children with autism spectrum disorders. Pediatrics. 2013 Nov. 132(5):833-40. [Medline].
Brauser D. Psychotropics Still Commonly Prescribed for Autism. Medscape [serial online]. Available at http://www.medscape.com/viewarticle/812982. Accessed: November 2, 2013.
McPheeters ML, Warren Z, Sathe N, Bruzek JL, Krishnaswami S, Jerome RN, et al. A systematic review of medical treatments for children with autism spectrum disorders. Pediatrics. 2011 May. 127(5):e1312-21. [Medline].
McDougle CJ, Kem DL, Posey DJ. Case series: use of ziprasidone for maladaptive symptoms in youths with autism. J Am Acad Child Adolesc Psychiatry. 2002 Aug. 41(8):921-7. [Medline].
Hollander E, Phillips A, Chaplin W, Zagursky K, Novotny S, Wasserman S, et al. A placebo controlled crossover trial of liquid fluoxetine on repetitive behaviors in childhood and adolescent autism. Neuropsychopharmacology. 2005 Mar. 30(3):582-9. [Medline].
Owley T, Walton L, Salt J, Guter SJ Jr, Winnega M, Leventhal BL, et al. An open-label trial of escitalopram in pervasive developmental disorders. J Am Acad Child Adolesc Psychiatry. 2005 Apr. 44(4):343-8. [Medline].
Namerow LB, Thomas P, Bostic JQ, Prince J, Monuteaux MC. Use of citalopram in pervasive developmental disorders. J Dev Behav Pediatr. 2003 Apr. 24(2):104-8. [Medline].
Couturier JL, Nicolson R. A retrospective assessment of citalopram in children and adolescents with pervasive developmental disorders. J Child Adolesc Psychopharmacol. 2002 Fall. 12(3):243-8. [Medline].
King BH, Hollander E, Sikich L, McCracken JT, Scahill L, Bregman JD, et al. Lack of efficacy of citalopram in children with autism spectrum disorders and high levels of repetitive behavior: citalopram ineffective in children with autism. Arch Gen Psychiatry. 2009 Jun. 66(6):583-90. [Medline].
Brasic JR, Zagzag D, Kowalik S, Prichep L, John ER, Barnett JY, et al. Clinical manifestations of progressive catatonia. Ger J Psychiatr. 2000. 3 (2):13-24. [Full Text].
Brasic JR, Zagzag D, Kowalik S, Prichep L, John ER, Liang HG, et al. Progressive catatonia. Psychol Rep. 1999. 84 (1):239-46.
Kem DL, Posey DJ, McDougle CJ. Priapism associated with trazodone in an adolescent with autism. J Am Acad Child Adolesc Psychiatry. 2002 Jul. 41(7):758. [Medline].
[Guideline] American Academy of Pediatrics. Management of Children With Autism Spectrum Disorder. Pediatrics. 2007 Nov;120(5):1183-1215. Available at http://pediatrics.aappublications.org/content/120/5/1162.full.
Rossignol DA. Hyperbaric oxygen therapy might improve certain pathophysiological findings in autism. Med Hypotheses. 2007. 68(6):1208-27. [Medline].
Rossignol DA, Rossignol LW. Hyperbaric oxygen therapy may improve symptoms in autistic children. Med Hypotheses. 2006. 67(2):216-28. [Medline].
Rossignol DA, Rossignol LW, James SJ, Melnyk S, Mumper E. The effects of hyperbaric oxygen therapy on oxidative stress, inflammation, and symptoms in children with autism: an open-label pilot study. BMC Pediatr. 2007 Nov 16. 7:36. [Medline]. [Full Text].
Williams K, Wray JA, Wheeler DM. Intravenous secretin for autism spectrum disorders (ASD). Cochrane Database Syst Rev. 2012 Apr 18. 4:CD003495. [Medline].
Cassels C. Oxytocin 'Normalizes' Social Deficits in Kids With Autism. Medscape Medical News. Available at http://www.medscape.com/viewarticle/817552. Accessed: December 16, 2013.
Gordon I, Vander Wyk BC, Bennett RH, Cordeaux C, Lucas MV, Eilbott JA, et al. Oxytocin enhances brain function in children with autism. Proc Natl Acad Sci U S A. 2013 Dec 2. [Medline].
Celexa (citalopram hydrobromide) [package insert]. St. Louis, Missouri: Forest Pharmaceuticals, Inc; August, 2011. [Full Text].
US Food and Drug Administration. Celexa (citalopram hydrobromide): Drug safety communication – abnormal heart rhythms associated with high doses. Available at http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm269481.htm. Accessed: October 24, 2012.
A Message From APA President Dilip Jeste, M.D., on DSM-5. Available at http://www.psychnews.org/files/DSM-message.pdf. Accessed: December 1, 2012.
American Psychiatric Association. DSM-5 Development, Autism Spectrum Disorder. Proposed Revision. Available at http://www.dsm5.org/ProposedRevisions/Pages/proposedrevision.aspx?rid=94. Accessed: December 22, 2011.
APA. Autism Spectrum Disorder. Available at http://www.dsm5.org/Documents/Autism%20Spectrum%20Disorder%20Fact%20Sheet.pdf.. Accessed: July 1, 2013.
Brauser D. Abnormal Placentas May Signal Autism Risk. Medscape Medical News. Available at http://www.medscape.com/viewarticle/803331. Accessed: May 14, 2013.
Brauser D. Developmental Delays Detectable in High-risk 1-Year-Olds. Medscape Medical News. Available at http://www.medscape.com/viewarticle/821851. Accessed: March 17, 2014.
Brauser D. Routine Ultrasound Scans May Detect Autism in Utero. Medscape Medical News. Available at http://www.medscape.com/viewarticle/827333. Accessed: July 2, 2014.
Brauser D. Some kids 'age out' of autism. Medscape Medical News. January 23, 2013. Available at http://www.medscape.com/viewarticle/778061. Accessed: January 29, 2013.
Corrigan NM, Shaw DW, Estes AM, Richards TL, Munson J, Friedman SD, et al. Atypical Developmental Patterns of Brain Chemistry in Children With Autism Spectrum Disorder. JAMA Psychiatry. 2013 Jul 31. [Medline].
Frazier TW, Youngstrom EA, Speer L, Embacher R, Law P, Constantino J, et al. Validation of proposed DSM-5 criteria for autism spectrum disorder. J Am Acad Child Adolesc Psychiatry. 2012 Jan. 51(1):28-40.e3. [Medline]. [Full Text].
Harrison P. Novel Drug Modifies Core Autism Symptoms in Adults. Medscape Medical News. May 27 2014. [Full Text].
Huerta M, Bishop SL, Duncan A, Hus V, Lord C. Application of DSM-5 Criteria for Autism Spectrum Disorder to Three Samples of Children With DSM-IV Diagnoses of Pervasive Developmental Disorders. . Am J Psychiatry 2012;169:1056-1064. [Full Text].
Mandy WP, Charman T, Skuse DH. Testing the construct validity of proposed criteria for DSM-5 autism spectrum disorder. J Am Acad Child Adolesc Psychiatry. 2012 Jan. 51(1):41-50. [Medline].
Marcus RN, Owen R, Kamen L, Manos G, McQuade RD, Carson WH, et al. A placebo-controlled, fixed-dose study of aripiprazole in children and adolescents with irritability associated with autistic disorder. J Am Acad Child Adolesc Psychiatry. 2009 Nov. 48(11):1110-9. [Medline].
McCracken JT, McGough J, Shah B, Cronin P, Hong D, Aman MG, et al. Risperidone in children with autism and serious behavioral problems. N Engl J Med. 2002 Aug 1. 347(5):314-21. [Medline].
Owen R, Sikich L, Marcus RN, Corey-Lisle P, Manos G, McQuade RD, et al. Aripiprazole in the treatment of irritability in children and adolescents with autistic disorder. Pediatrics. 2009 Dec. 124(6):1533-40. [Medline].
Ozonoff S, Young GS, Belding A, et al. The Broader Autism Phenotype in Infancy: When Does It Emerge?. J American Academy Child Adolesc Psychiatry. 2014 Jan 23. [Epub ahead of print].
Stetka B, Correll, C. A Guide to DSM-5: Autism Spectrum Disorders. Medscape Medical News. Available at http://www.medscape.com/viewarticle/803884_4. Accessed: July 1, 2013.
Walker CK, Anderson KW, Milano KM, Ye S, Tancredi DJ, Pessah IN, et al. Trophoblast Inclusions Are Significantly Increased in the Placentas of Children in Families at Risk for Autism. Biol Psychiatry. 2013 Apr 22. [Medline].