Asperger syndrome (AS), also known as Aspergers, was the name of a neurodevelopmental disorder no longer recognised as a diagnosis in itself, having been merged into autism spectrum disorder (ASD). It was characterized by significant difficulties in social interaction and nonverbal communication, along with restricted and repetitive patterns of behaviour and interests. It was said to differ from other diagnoses that were merged into ASD by relatively unimpaired language and intelligence. The syndrome was named after the Austrian pediatrician Hans Asperger, who, in 1944, described children in his care who struggled to form friendships, did not understand others gestures or feelings, engaged in one-sided conversations about their favourite interests, and were clumsy.The exact cause of Aspergers is poorly understood. While it has high heritability, the underlying genetics have not been determined conclusively. Environmental factors are also believed to play a role. Brain imaging has not identified a common underlying condition.In 1994, the diagnosis of Aspergers was included in the fourth edition (DSM-IV) of the American Diagnostic and Statistical Manual of Mental Disorders; with the publication of DSM-5 in 2013 the diagnosis was removed, and the symptoms are now included within autism spectrum disorder along with classic autism and pervasive developmental disorder not otherwise specified (PDD-NOS).
Although research into the efficacy of pharmaceutical intervention for AS is limited, it is essential to diagnose and treat comorbid conditions. Deficits in self-identifying emotions or in observing effects of ones behavior on others can make it difficult for individuals with AS to see why medication may be appropriate. Medication can be effective in combination with behavioral interventions and environmental accommodations in treating comorbid symptoms such as anxiety disorders, major depressive disorder, inattention, and aggression. The atypical antipsychotic medications risperidone, olanzapine and aripiprazole have been shown to reduce the associated symptoms of AS; risperidone can reduce repetitive and self-injurious behaviors, aggressive outbursts, and impulsivity, and improve stereotypical patterns of behavior and social relatedness. The selective serotonin reuptake inhibitors (SSRIs) fluoxetine, fluvoxamine, and sertraline have been effective in treating restricted and repetitive interests and behaviors, while stimulant medication, such as methylphenidate, can reduce inattention.Care must be taken with medications, as side effects may be more common and harder to evaluate in individuals with AS, and tests of drugs effectiveness against comorbid conditions routinely exclude individuals from the autism spectrum. Abnormalities in metabolism, cardiac conduction times, and an increased risk of type 2 diabetes have been raised as concerns with antipsychotic medications, along with serious long-term neurological side effects. SSRIs can lead to manifestations of behavioral activation such as increased impulsivity, aggression, and sleep disturbance. Weight gain and fatigue are commonly reported side effects of risperidone, which may also lead to increased risk for extrapyramidal symptoms such as restlessness and dystonia and increased serum prolactin levels.