Trajectories and predictors of suicidal ideation in clinical characteristics and pharmacological treatments for major depressive disorder: a study based on a national multi-centered prospective cohort

Suicidal ideation (SI) is a significant precursor and risk marker for suicide behaviors in major depressive disorder (MDD). Exploration of SI trajectory from a longitudinal framework are essential for treatment guidelines and clinical management of suicide risk. This study sought to explore SI trajectories and its associated clinical, sociodemographic characteristics, and initial treatment among patients with MDD. We used data from a non-interventional, national multi-centered prospective cohort study. 1 461 patients with MDD were included in the growth mixture modeling using SI at baseline, 2 weeks, 4 weeks, 8 weeks, 12 weeks, and 6 months, 9 months, and 12 months as the indicator. A multinomial regression was employed with SI trajectory as the outcome and anhedonia, depressive symptoms, atypical depressive symptoms, pharmacological treatments, and other covariates as the predictors. Four distinct SI trajectories were identified: a consistently low SI trajectory(50.7%), a persistently mild SI trajectory(20.6%), a fast declined SI trajectory(8.9%), and a slowly declined trajectory(19.8%). Compared to those with a consistently low SI trajectory, a higher score of anhedonia was associated with an increased risk of experiencing persistently mild (RRR = 1.20, 95%CI: 1.05, 1.38) and slowly declined SI (1.54, 95%CI: 1.32, 1.80). Severity of depressive symptom was also positively associated with the risk of experiencing persistently mild (1.15, 95%CI: 1.13, 1.18) and slowly declined SI (1.17, 95%CI: 1.14, 1.21). And the risk of experiencing slowly declined SI was higher for those use SSRI(1.49, 95%CI: 1.02, 2.31), and for those use antidepressant and antipsychotic/mood stabilizer combined therapy (3.78, 95%CI: 1.48, 9.61). The findings of this study are potentially useful for clinical practice as critical indicators of profiles and interventions for prognosis among patients with MDD. Further research is warranted to explore potential modifiable factors and the association between SI trajectories and suicide behavior.