Objectives:
The study aims to define the differences in clinical manifestation among adolescent girls and boys with autism spectrum disorder (ASD).

Methods:
The study group consisted of 15 adolescent girls and 16 adolescent boys with diagnosis of autismor Asperger syndrome and their parents. Adolescents were assessed with ADOS (Autism Diagnostic Observation Schedule, Polish adaptation of the assessment), algorithms of ADOS and ADOS-2 (revised version) were compared. Structured interview was conducted with parents, they fulfilled AQ (Autism Quotient), ASAS (Australian Scale for Asperger Syndrome), GQ-ASC (Girls’ Questionnaire for Autism Spectrum Conditions). Medical records were analyzed. Results were analyzed using statistical methods.

Results:
Patients were assessed with ADOS Module 4. Results indicated statistically significant differences between ASD girls and ASD boys in communication section, both verbal and gestures. The mean scores of AQ for ASD girls and ASD boys were M = 33.0 and M=30.9, and of ASAS M =57% and M =61% respectively. ASD girls had more psychiatric hospitalisations than ASD boys (60% vs. 31%), and they were more often treated with antidepressants (67% vs. 31%), anxiolytics (20% vs. 6%), mood stabilizers (40% vs. 19%). ASD boys were more often treated with psychotropic medications (50% vs. 47%) and stimulants (44% vs. 20%) than ASD girls.

Conclusions:
ASD girls are at risk of receiving non-spectrum classification in ADOS or ADOS-2 while their developmental history and clinical manifestation confirm ASD. Clinical data suggests that ASD girls present more abnormalities in sensory profile. ASD girls are at greater risk for developing anxiety, depression, suicidal ideation, and for psychiatric hospitalization. ASD boys appear to be at greater risk for co-occurring ADHD, OCD and tics.