<Li> The male to female ratio of 4: 1 for HFA is much smaller than that of Asperger syndrome </Li> <P> Individuals with autism spectrum disorders, including high - functioning autism, risk developing symptoms of anxiety . While anxiety is one of the most commonly occurring mental health symptoms, children and adolescents with high functioning autism are at an even greater risk of developing symptoms . </P> <P> There are other comorbidities, the presence of one or more disorders in addition to the primary disorder, associated with high - functioning autism . Some of these include depression, bipolar disorder, and obsessive compulsive disorder (OCD). In particular the link between HFA and OCD, has been studied; both have abnormalities associated with serotonin . </P> <P> Observable comorbidities associated with HFA include ADHD, Tourette syndrome, and possibly criminal behavior . While the association between HFA and criminal behavior is not completely characterized, several studies have shown that the features associated with HFA may increase the probability of engaging in criminal behavior . While there is still a great deal of research that needs to be done in this area, recent studies on the correlation between HFA and criminal actions suggest that there is a need to understand the attributes of HFA that may lead to violent behavior . There have been several case studies that link the lack of empathy and social naïveté associated with HFA to criminal actions . </P>

What are the characteristics of high functioning autism