Are people with autism spectrum disorders affected by mental

illness?

There is an overlap between the core features of autism and symptoms of mental illness. This can lead to misdiagnosis and the incorrect management of individuals. In addition people with autism may appear to present with symptoms of major mental illness at times when stress, transition and life events impact on their usual daily routine. Misdiagnosis may become evident when the expected improvement with treatment does not occur, or there is only a partial improvement and there are residual symptoms. It is important to perform a comprehensive assessment to prevent misdiagnosis. Physical investigations are important as a person with autism may not recognise when they are physically unwell and medical illness can be missed. Any psychiatric disorder can occur in people with autism spectrum disorder and anxiety and depression are common as are sleep and eating problems. Schizophrenia, Tourette’s Disorder, Catatonia and Bipolar Disorder are important diagnoses to consider but are not as common. Obsessive compulsive symptoms are often seen but it can be difficult to decide if these are part of an obsessive compulsive disorder or due to the autism itself. Many of the difficulties in diagnosing mental illness in people with an intellectual disability apply to people with autism.