Among mood disorder patients, comorbid personality disorders (PDs) increase the risk of suicide attempts (SAs) to approximately two-fold.
The excess risk is mostly due to patients with comorbid PDs spending more time in major depressive episodes (MDEs) than those without.
All DSM-IV PD clusters increased the rate of new SAs, although cluster C PDs more than the others.
After adjusting for time spent in MDEs, only cluster C further increased the SA rate.
Direct risk-modifying effects of PDs were also found.