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.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 bipolar disorder and obsessive–compulsive disorder (OCD). In particular the link between HFA and OCD, has been studied; both have abnormalities associated with serotonin.Observable comorbidities associated with HFA include ADHD and Tourette syndrome. HFA does not cause, nor include, intellectual disabilities. This characteristic distinguishes HFA from low-functioning autism; between 40 and 55% of individuals with autism also have an intellectual disability. Behavior
An 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.There is still a need for more research on the link between HFA and crimes, because many other studies point out that most people with ASD are more likely to be victims and less likely to commit crimes than the general population.
Additionally, individuals with "medium-functioning autism" are typically left out of the discussion entirely, and due to the non-linear nature of the autistic spectrum, individuals can be high-functioning in some areas while at the same time being medium or low functioning in other areas. See also
Asperger syndrome and neuroscience
Autism-spectrum quotient, a self-administered test for high-functioning autism
Historical figures sometimes considered autistic
Low-functioning autism
Nonverbal learning disorder
Lorna Wing

References
Further reading
Robison, John Elder (2007). Look Me in the Eye: My Life with Aspergers. Three Rivers Press. ISBN 9780307395986.