Background: Depressed suicide attempters are, according to some earlier studies, treated more often with antipsychotics than depressive non-suicide attempters. Cluster B personality disorders, especially borderline personality disorder, are associated with a high suicide risk, and antipsychotics are commonly used for the reduction of symptoms. However, no previous study has taken comorbid personality disorders into account when assessing the use of antipsychotics in patients with unipolar depression. Therefore, the aim of this study was to investigate the clinical selection of pharmacotherapy in unipolar depression with and without a previous suicide attempt, taking into account potential confounders such as cluster B personality disorders. Methods: The study sample consisted of 247 patients with unipolar depression. The study was approved by the Regional Ethical Review Board in Lund, Sweden. Study participants were recruited from 4 different secondary psychiatric care clinics in Sweden and were diagnosed according to the DSM-IV-TR with the MINI and SCID II. Previous and ongoing psychiatric treatments were investigated in detail and medical records were assessed. Results: Thirty percent of the patients had made previous suicide attempts. Depressed suicide attempters underwent both lifetime treatment with antipsychotics and an ongoing antipsychotic treatment significantly more often than non-attempters. Significances remained after a regression analysis, adjusting for cluster B personality disorders, symptom severity, age at the onset of depression, and lifetime psychotic symptoms. Conclusions: This is the first study to consider the effect of comorbidity with cluster B personality disorders when comparing treatment of depressive suicide and non-suicide attempters. Our findings suggest that suicide attempters are more frequently treated with antipsychotics compared to non-suicide attempters, regardless of cluster B personality disorder comorbidity. These findings are important for clinicians to consider and would also be relevant to future studies evaluating reduction of suicide risk with antipsychotics in patients with psychiatric comorbidity and a history of attempted suicide.