The objective of this review is to examine clinical trials of the treatment of personality disorders (PDs). The method is a narrative review of published controlled trials of psychotherapy and pharmacotherapy. Results show that a variety of methods reduce impulsivity, with less striking results for affective instability. There is good support for well-structured methods of psychotherapy, mainly in borderline personality disorder (BPD), but evidence for the efficacy of pharmacotherapy is weak. Research on other PD categories is sparse.