The aim of this study was to investigate the factors associated with the past history of suicide attempts in high-dose regular benzodiazepine (BZD) users (HDRUs). 55 HDRUs were compared to matched controls. Using logistic regression analysis, it was found that only comorbid borderline personality disorder (BPD), not high-dose BZD use, was independently associated with a history of suicide attempt. The percentage of patients with a history of suicide attempt was significantly higher in HDRUs with comorbid BPD, compared to those without BPD. (29 refs)