Suicidal risk in bipolar I disorder patients and adherence to long-term lithium treatment

Objectives: Among the well-established treatments for bipolar disorder (BPD), lithium continues to offer an unusually broad spectrum of benefits that may include reduction of suicidal risk. Methods: We examined the association of suicidal acts with adherence to long-term lithium maintenance treatment and other potential risk factors in 72 BP I patients followed prospectively for up to 10 years at a Mood Disorders Research Center in Spain. Results: The observed rates of suicide were 0.143, and of attempts, 2.01%/year, with a 5.2-fold (95% CI: 1.5-18.6) greater risk among patients consistently rated poorly versus highly adherent to lithium prophylaxis (11.4/2.2 acts/100 person-years). Treatment non-adherence was associated with substance abuse, being unmarried, being male, and having more hypomanic-manic illness and hospitalizations. Suicidal risk was higher with prior attempts, more depression and hospitalization, familial mood disorders, and being single and younger, as well as treatment non-adherence, but with neither sex nor substance abuse. In multivariate analysis, suicidal risk was associated with previous suicidality > poor treatment adherence > more depressive episodes > younger age. Conclusions: The findings support growing evidence of lower risk of suicidal acts during closely monitored and highly adherent, long-term treatment with lithium and indicate that treatment adherence is a potentially modifiable factor contributing to antisuicidal benefits.