Navigation Links
Autism's earliest symptoms not evident in children under 6 months
Date:2/15/2010

(SACRAMENTO, Calif.) A study of the development of autism in infants, comparing the behavior of the siblings of children diagnosed with autism to that of babies developing normally, has found that the nascent symptoms of the condition a lack of shared eye contact, smiling and communicative babbling are not present at 6 months, but emerge gradually and only become apparent during the latter part of the first year of life.

Researchers conducted the study over five years by painstakingly counting each instance of smiling, babbling and eye contact during examinations until the children were 3. They found that by 12 months the two groups' development had diverged significantly. Intentional social and communicative behavior among children developing normally increased while among infants later diagnosed with autism it decreased dramatically. The study is published online early and will appear in the March issue of the Journal of the American Academy of Child & Adolescent Psychiatry.

"This study provides an answer to when the first behavioral signs of autism become evident," said Sally Ozonoff, the study's lead author, a professor of psychiatry and behavioral sciences and a researcher with the UC Davis MIND Institute. "Contrary to what we used to think, the behavioral signs of autism appear later in the first year of life for most children with autism. Most babies are born looking relatively normal in terms of their social abilities but then, through a process of gradual decline in social responsiveness, the symptoms of autism begin to emerge between 6 and 12 months of age."

Autism is a pervasive developmental disorder of deficits in social skills and communication, as well as in repetitive and restricted behaviors, with onset occurring prior to age 3. Abnormal brain development, probably beginning prenatally, is known to be fundamental to the behaviors that characterize autism. Current estimates place the condition's incidence at between 1 in 100 and 1 in 110 children in the United States.

Children with a sibling already diagnosed with autism are known to be among those at greatest risk of developing the disorder. The current study included 25 high-risk children who met criteria for autism at 3 years of age, matched with 25 low risk peers who were developing normally. It was conducted at the MIND Institute and the University of California, Los Angeles. The sole inclusion criterion for the high-risk group was having a sibling with autism; low-risk participants had to have been born after 36 weeks gestation and have no autistic family members.

The children's development was evaluated at 6, 12, 18, 24 and 36 months of age using a series of widely implemented diagnostic tools, including the Autism Diagnostic Observation Schedule (ADOS) and the Autism Diagnostic Interview-Revised (ADI-R). Examiners were not told which babies were at high- or low-risk when evaluating the participants' development.

The researchers found that there were few discernable differences between the two groups at the outset but that after six months, 86 percent of the infants who developed autism showed declines in social communication that were outside the range for typical development. "After six months," the study found, "the autism spectrum disorder group showed a rapid decline in eye contact, social smiling, and examiner-rated social responsiveness." Group differences were significant by 12 months in eye contact and social smiling and all other measures by 18 months, the study found.

The study is notable because of the accuracy and precision of its prospective methodology, assiduously recording exact numbers of social and communicative behaviors during lab visits. Previously, researchers have constructed evidence of autism's earliest manifestations by interviewing parents about when they believed their children's symptoms first arose or by reviewing home movies for clues to when children begin exhibiting symptoms of autism.

"Until now, research has relied on asking parents when their child reached developmental milestones. But that can be really difficult to recall, and there is a phenomenon called the "telescoping effect" where people usually say that they remember something happening more recently than when it occurred," Ozonoff said. In addition parents frequently will turn off the video camera when their children are behaving poorly precisely when autistic symptoms may appear.

Ozonoff said that the study provides a deeper understanding for parents, caregivers and health-care providers and for future research of the developmental trajectory for very young children with autism.

"We need to be careful about how we screen, and we need to know what we're looking for," Ozonoff said. "This study tells us that screening for autism early in the first year of life probably is not going to be successful because there isn't going to be anything to notice. It also tells us that we should be focusing on social behaviors in our screening, since that is what declines early in life."

"This study also found that the loss of skills continues into the second and third year of life," she said. "So it may not be adequate, as the American Academy of Pediatrics currently suggests, that providers screen for autism twice before the end of the second year. Autism has a slow, gradual onset of symptoms, rather than a very abrupt loss of skills."

"Screening may need to continue into the third year of life, since symptom emergence takes place over a long time. If a child starts exhibiting a declining trajectory and a sustained reduction in social communication we want to refer them into therapy, especially if they are at risk," Ozonoff said, "even before we might be able to make a definitive diagnosis."

Ozonoff said that the study does not address the etiology of autism or causality. In this study, the infants who participated were at high risk due to having strong family histories of autism, suggesting that genetics play a major role in the later autism diagnoses, despite the fact that their symptoms were not apparent at birth.


'/>"/>

Contact: Phyllis Brown
phyllis.brown@ucdmc.ucdavis.edu
916-734-9023
University of California - Davis - Health System
Source:Eurekalert

Related medicine news :

1. Blood protein detects lung cancer, even at earliest stage
2. Scripps research scientists devise approach that stops HIV at earliest stage of infection
3. Majority of kidney cancers diagnosed at earliest stage
4. UCLA researchers image earliest signs of Alzheimers, before symptoms appear
5. DNA of Jesus-era shrouded man in Jerusalem reveals earliest case of leprosy
6. New treatment effective in counteracting cocaine-induced symptoms
7. Study suggests loss of 2 types of neurons -- not just 1 -- triggers Parkinsons symptoms
8. Effectiveness of mouse breeds that mimic Alzheimers disease symptoms questioned
9. New study: Pine bark reduces perimenopausal symptoms
10. Cell that triggers symptoms in allergy attacks can also limit damage, Stanford researchers find
11. Clean to Ease Allergy and Asthma Symptoms
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/9/2016)... ... February 09, 2016 , ... ... production of its newest mobility device, the StandUp Walker. Made entirely in the ... in the last 50 years. , StandUp Walker’s novel patent-pending design offers 2-in-1 ...
(Date:2/9/2016)... ... February 09, 2016 , ... ... LLC to help enterprises move workloads to the cloud. Cirracore provides a ... their cloud without traversing the Internet. Transformation Solutions (TSL Partners) provides a ...
(Date:2/9/2016)... ... February 09, 2016 , ... BioPlus Specialty Pharmacy (BioPlus), one ... ‘Pay It Forward’ program into 2016. BioPlus partners with several non-profit patient foundations ... , “Since our Pay It Forward program began, we are proud to have ...
(Date:2/9/2016)... ... ... On January 12, 2016 Paul McElwee, a CroppMetcalfe HVAC technician, visited a home ... any heat. Shortly after entering the home, Paul was able to identify the problem ... carbon monoxide into the home, at 2,000 parts per million in the flue. Anything ...
(Date:2/9/2016)... ... February 09, 2016 , ... The Bon-Ton Stores, Inc. ... department stores, announced it has raised $176,000 to benefit the Breast Cancer Research ... Center at the University of Iowa, The Lynn Sage Cancer Research Foundation, and ...
Breaking Medicine News(10 mins):
(Date:2/9/2016)... "Company") (NASDAQ: UNIS ; ASX: UNS), a developer and ... for the second quarter of fiscal 2016 (three months ended December ... Financial Results for the Second Quarter of Fiscal 2016 ... the second quarter of fiscal 2016 was $4.5 million, compared to ... customers for the second quarter of fiscal 2016 were $17.8 million, ...
(Date:2/9/2016)... 2016  Axovant Sciences Ltd. (NYSE:  AXON), a ... of dementia, today announced further details of three ... functional aspects of Lewy body dementia, a disease ... Two out of the three studies were recently ... later this quarter. In addition, the Company reported ...
(Date:2/9/2016)... Hearing protection devices refer to the barriers that reduce ... ear. Hearing protection devices include earplugs, uniform attenuation earplug, ... users exposed to noise levels of over 80 dB ... inserted in the ear canal to protect the ear. ... sound perception with the help of acoustic filters. Earmuffs ...
Breaking Medicine Technology: