• attempts;
  • bipolar disorders;
  • ideation;
  • major depression;
  • risk factors;
  • sex;
  • suicide;
  • temperament

Objective:  We estimated risks of suicidal behaviors in 2826 mood-disorder patients evaluated and followed in a Sardinian mood disorders research center over the past 30 years.

Method:  We determined rates of suicidal ideation, attempts, and suicides, with associated risk factors, in men and women with DSM-IV bipolar I (BP-I; n = 529), BP-II; (= 314), or major depressive disorders (MDD; = 1983), at risk for an average of 11 years of illness.

Results:  Observed rates (% of patients/year) of suicide ranked: BP-II (0.16) ≥ BP-I (0.14) > MDD (0.05); attempts: BP-I (1.52) > BP-II (0.82) > MDD (0.48); ideation: BP-II (42.7) > MDD (33.8) > BP-I (22.7). The ratio of attempts/suicides (lethality index) ranked: BP-II (5.12) < MDD (9.60) ≤ BP-I (10.8). Male/female risk-ratios were greater for suicide than attempts or ideation. One-third of all reported acts occurred within the first year of illness, and earliest among MDD patients. Factors associated independently with suicidal acts included BP diagnosis, hospitalizations/person, and early illness-onset; factors associated with suicidal ideation were having an affective temperament, BP-II diagnosis, and higher suicidality-corrected depression score at intake.

Conclusion:  Suicidal behaviors were more prevalent among BPD than MDD out-patients.