Changes in suicidal ideation during treatment among patients with major depressive disorder: A 6-month naturalistic follow-up study.

Aim: There is limited evidence regarding predictors of changes in suicidal ideation (SI) in patients with major depressive disorder (MDD). The objective of this study was to describe changes in SI over a 6-month period and identify their predictors from naturalistic observations of MDD patients.

Methods: In the cross-sectional analysis, we examined 257 patients with MDD at the first-visit assessment. Among the patients, 119 who completed the 6-month assessment (completers) were included in the longitudinal analysis. For the evaluation of depressive symptoms, including SI, the Quick Inventory of Depressive Symptomatology-Japanese version was administered at both the first-visit and follow-up assessments. At baseline, we also administered the Japanese version of the Ten Item Personality Inventory to assess personality traits and the PRIME Screen-Revised to assess psychotic symptoms.

Results: In the cross-sectional analysis of first-visit patients, 36.2% (93/257) exhibited SI. Among completers, 14.3% (17/119) had prolonged SI. Among the completers with SI at the first-visit assessment, 38.6% (17/44) had SI at the follow-up assessment (prolonged SI). In linear regression models including all completers, prolonged SI was positively associated with endorsement of suspiciousness/persecutory ideas and negatively associated with higher age.

Conclusion: More than one-third of completers who had SI at the first-visit assessment experienced prolonged SI (SI at follow-up). Our findings can help clinicians predict the course of MDD by identifying associated demographic and clinical characteristics.