PurposeThis study estimated the prevalence of depressive disorders among PhD students and analyzed the underlying factors in the Indian context.Design/methodology/approachThe authors utilized an “Integrative framework” and a mixed-method approach involving survey and in-depth interviews. The survey was conducted among 240 PhD students using multistage cluster sampling in two public universities of Kerala, India. Data were collected using a self-administered Patient Health Questionnaire-9. In-depth interviews were conducted among 12 students using semi-structured interview guide. Multinomial regression and thematic analyses were undertaken to examine the factors associated with depressive disorders.FindingsAbout 31.7, 41.7, 17.9, 6.7 and 2.1% had no/minimal, mild, moderate, moderately severe and severe depressive disorders, respectively. Students belonging to economically weaker section (OR = 3.06; 95% CI = 1.32–7.12), having limited knowledge of local language (OR = 4.24; 95% CI = 1.00–17.95) and earning less than INR 20,000/month (OR = 2.36; 95% CI = 1.12–5.00) were more likely to report moderate to severe depressive disorders. In addition, thematic analyses of interviews found that financial hardship, disagreement between student-supervisor, compromised students' support services and an uncertain job market were the key factors affecting the mental health of students and inhibiting academic performance.Originality/valueThis study adds to the existing literature by examining the prevalence and underlying factors of depressive disorders among doctoral students in the Indian context. The results of this study can act as a guide for universities and educational regulatory bodies to address the burgeoning issue of depressive disorders among research students in India.