Disorders characterized by impulsivity include disorders of impulse control (intermittent explosive disorder, pyromania, kleptomania, pathological gambling and trichotillomania), paraphilias, sexual impulsions and sexual addictions and impulsive aggression personality disorders (borderline, antisocial, histrionic and narcissistic personality disorders). Impulsivity has a substantial impact on both individuals and society. Impulse control disorders may be conceptualized as a subset of the obsessive-compulsive spectrum. In this article, we examine the genetic and neurobiological aetiology of these disorders and possible treatment options. The link between serotonergic dysfunction and the pathophysiology of impulsivity is discussed, and studies that examine the efficacy of various selective serotonin reuptake inhibitors and other alternatives in the treatment of impulsive disorders such as pathological gambling, sexual addictions and borderline personality disorder are presented.