Background: Understanding the prevalence and associated factors of suicidal ideation among patients with major depressive disorder (MDD) can help develop strategies to prevent deaths by suicide. However, data in this area for Southeast Asia is limited.

Objective: To investigate the prevalence and factors associated with suicidal ideation and its severity among patients with MDD in Thailand.

Materials and Methods: A cross-sectional study was conducted via a retrospective medical chart review of 329 patients with MDD who visited a psychiatric outpatient clinic. Data about suicidal ideation were collected using the ten-item diagnostic Montgomery-Åsberg Depression Rating Scale (MADRS) that consider risk factors such as patient background, medical conditions, co-morbid psychiatric disorders, and family history. The data was collected from the medical records and was analyzed by using logistic regression and Mann-Whitney U test to determine factors associated with suicidal ideation and factors associated with severity of suicidal ideation, respectively.

Results: The prevalence of suicidal ideation among patients suffering from MDD was 82.1%. Chronic physical illness was associated with an increased risk of suicidal ideation (adjusted odds ratio 1.87, p=0.04) and substance use disorder was a significant predictor of severity of suicidal ideation (p=0.036).

Conclusion: Chronic physical illnesses and substance use disorder can increase risk for suicidal ideation in patients with MDD. Early identification of patients with these risk factors may prevent transition from suicidal ideation to suicide attempt.

Keywords: Suicidal ideation; Major depressive disorder; Chronic illness; Substance use disorder

DOI: 10.35755/jmedassocthai.2022.02.13230

Received 12 July 2021 | Revised 27 October 2021 | Accepted 4 November 2021