Ratio of rates of suicide attempts to suicides in the general population and in mood disorder patients

Attempt/suicide rate-ratios indicate lethality in clinical samples, but comparisons with nonclinical populations require better information on attempt-rates. We conducted a protocol-based, systematic review to identify reports of attempt (A) and suicide (S) rates per 100,000 person-exposure years (100k PEY) in general-population samples, compared with corresponding standardized rates from large clinical samples of men and women diagnosed with DSM-5-TR bipolar disorder (BD) or major depressive disorder (MDD). In 50 international reports (81M nonclinical subjects), A averaged 178/100k PEY [CI: 123–234] (men), 270 [188–353] (women); S averaged 17.4 [15.3–19.5] (men), 6.50 [5.42–7.58] (women); A/S averaged 9.56 [6.97–12.2] (men), 45.1 [34.2–56.0] (women), 27.4 [20.6–34.2] overall. Among 4388 mood-disorder patients (62.7% women, 33.3% BD), rates averaged: BD-men: A 908, S 165, A/S 5.49; MDD men: A 451, S 52.0, A/S 8.67; BD-women: A 1210, S 46.1, A/S 26.2; MDD-women: A 513, S 24.9, A/S 20.6. Rate-ratios for mood-disorder vs. general-population samples were: men: A 3.76, S 6.32, A/S 1/1.57; women: A 2.84, S 4.66, A/S 1/1.78. Regional and temporal variability in reported suicide attempt rates and variance in ascertainment methods probably contribute to difficulties in identifying suicide attempts accurately worldwide. A averaged 224, S 12.0, and A/S 27.4/100k PEY in general-population samples. Standardized rates of A and S were higher and A/S lower with mood-disorders vs. nonclinical samples, with consistently greater suicidal lethality (4.15-fold lower A/S: 6.09 vs. 25.3) in men vs. women. • The ratio of attempt/suicide rates (A/S) is proposed as a suicidal “lethality index” • Systematic review (k=50) of suicidal rates provided general-population estimates • General-population attempt/suicide (A/S) rate-ratio was 45.1 in women, 9.56 in men • Among mood-disorder patients, overall A/S rate-ratio was 25.3 in women, 6.09 in men • By A/S ratio, lethality was consistently greater among men