The psychopharmacology of autism spectrum disorder and Rett syndrome

Autism spectrum disorder (ASD) appears in early childhood and is characterized by persistent deficits in communication and social interaction, as well as restricted interests, repetitive behaviors, and unusual sensory issues. ASD can be idiopathic or syndromic, in the latter case representing one of the many manifestations of a genetic disorder, such as Rett syndrome. Psychopharmacology cannot directly ameliorate core autistic symptoms, but rather aims at treating comorbid disorders, such as ADHD, sleep disturbances, psychomotor agitation and aggressiveness, seizures, and anxiety. Until the 1990s, it was mainly based on typical neuroleptics and tricyclic antidepressants, whereas second-generation antipsychotics later became first-line drugs for these same indications. In general, selective serotonin reuptake inhibitors have not proven effective in ASD patients. Psychostimulants are frequently prescribed, but display modest efficacy and enhanced potential for side effects and noncompliance. Targeted patients benefit from mood stabilizers and antiepileptic drugs. Experimental drug treatments for ASD include oxytocin and vasopressin, bumetanide, sulforaphane, nutritional supplements, memantine, and d-cycloserine. Work performed on syndromic forms, represents an important source of information for experimental therapies of ASD and knowledge of the unique mechanisms underlying autism in each individual patient may in the future pave the path to personalized drug treatments.