Longitudinal evaluations were conducted on 61 adults who were referred to aMood Disorders Unit with a history of depression (all index episodesreached criteria for DSM-III-R major depression or dysthymia) and who hadcompleted a cognitive behavioural therapy group either on its own or incombination with an assertion training group. Assessment of personality wasmade using DSM-III-R Axis II personality disorder categories. Thesecategories were aggregated to form three groups: (i) no personalitydisorder; (ii) Cluster B (dramatic-erratic); and(iii) Cluster C (anxious-fearful), and were used to identify responsivenessto treatment and outcome at long-term follow-up. A battery of self-reportmeasures were administered pretreatment, posttreatment and at long-termfollow-up (1–3 years later). Both groups showed significantimprovements in mean scores during treatment and these gains were maintainedover the follow-up period. However, improvement in those patients withoutpersonality disorders was greater at posttreatment and at long-termfollow-up, both in level of depressive symptomatology and proportion ofcases meeting criteria for recovery. The treatment implications of theseresults are discussed.