Factors related to suicide attempts among individuals with major depressive disorder

Chidchanok Ruengorn^1,2, Kittipong Sanichwankul³, Wirat Niwatananun², Suwat Mahatnirunkul³, Wanida Pumpaisalchai³, Jayanton Patumanond^1
1Clinical Epidemiology Unit, Faculty of Medicine, ²Department of Pharmaceutical Care, Faculty of Pharmacy, Chiang Mai University, Chiang Mai, Thailand; 3Suanprung Psychiatric Hospital, Chiang Mai, Thailand

Background: Major depressive disorder (MDD) is the leading cause of suicidal behaviors. Risk related to suicide attempts among individuals with MDD remains uninvestigated in upper northern Thailand, where the completed suicide rate is the highest in the nation.
Objective: To examine risk related to suicide attempts among individuals with MDD.
Methods: Individuals diagnosed with MDD using the International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10), codes F32.x and F33.x, seeking care at Suanprung Psychiatric Hospital between October 2006 and May 2009 were eligible. All individuals with MDD admitted due to suicide attempts were defined as cases (n = 186), and four controls per case were selected from those who did not attempt suicide on the same day or within a week of case selection (n = 914). Their medical charts were reviewed for sociodemographic and clinical factors influencing suicide attempts using multivariable logistic regression analysis.
Results: Factors related to suicide attempts were stressful life events (adjusted odds ratio [OR], 2.32; 95% confidence interval [CI]: 1.27–4.24), alcohol use (adjusted OR, 2.08; 95% CI: 1.29–3.34), intermittent or poor psychiatric medications adherence (adjusted OR, 2.25; 95% CI: 1.44–3.51), up to two previous suicide attempts (adjusted OR, 3.64; 95% CI: 2.32–5.71), more than two previous suicide attempts (adjusted OR, 11.47; 95% CI: 5.73–22.95), and prescribed antipsychotics (adjusted OR, 3.84; 95% CI: 2.48–5.95). Risk factors that were inversely related to suicide attempts were increasing years of MDD treatment; one to five years (adjusted OR, 0.22; 95% CI: 0.11–0.44), over five years (adjusted OR, 0.44; 95% CI: 0.23–0.86), and antidepressant prescribed (norepinephrine [NE] and/or serotonin reuptake inhibitors [SRIs], adjusted OR, 0.28; 95% CI: 0.10–0.78). The final model explained 85.8% probability of suicide attempts.
Conclusion: Seven key factors suggested from this study may facilitate clinicians to identify individuals with MDD at risk of suicide attempt and provide them close monitoring, timely assessment, and intensive treatments.

Keywords: mood disorders, affective disorders, suicide behaviors, risk factors