Background
Acute behavioral alterations have been frequently reported in patients with autism. However, the question as to whether behavioral problems undergo seasonal variations in autism remains to be addressed.
Material and Method
In a prospective observational study over 29 months, problem behaviors amongst 23 young adults with autism and intellectual disability living in a farm community center were assessed. Behavioral problems were recorded daily using the Rossago Behavioral Checklist. Data were collected on clinical characteristics, drug usage, changes in staff composition, daily schedule, rehabilitative activities, and food administration.
Results
Problem behaviors showed significant seasonal fluctuations. The frequency of problem behaviors showed a maximum in mid-April and a minimum in mid-October (mean difference: 1.24 behaviors).
Conclusions
Taken together, these data suggest the occurrence of significant seasonal fluctuations in problem behaviors amongst young adults with autism and intellectual disability. Further studies are needed to shed more light on the mechanisms underlying these fluctuations.

Keywords: Mental Disorders - psychology, Longitudinal Studies, Intellectual Disability - psychology, Autistic Disorder - psychology, Seasons