Prevalence of Depression, Depressive Symptoms, and Suicidal Ideation Among Medical Students: A Systematic Review and Meta-Analysis

Abstract

Importance: Medical students are at high risk for depression and suicidal ideation. However, the prevalence estimates of these disorders vary between studies.

Objective: To estimate the prevalence of depression, depressive symptoms, and suicidal ideation in medical students.

Data sources and study selection: Systematic search of EMBASE, ERIC, MEDLINE, psycARTICLES, and psycINFO without language restriction for studies on the prevalence of depression, depressive symptoms, or suicidal ideation in medical students published before September 17, 2016. Studies that were published in the peer-reviewed literature and used validated assessment methods were included.

Data extraction and synthesis: Information on study characteristics; prevalence of depression or depressive symptoms and suicidal ideation; and whether students who screened positive for depression sought treatment was extracted independently by 3 investigators. Estimates were pooled using random-effects meta-analysis. Differences by study-level characteristics were estimated using stratified meta-analysis and meta-regression.

Main outcomes and measures: Point or period prevalence of depression, depressive symptoms, or suicidal ideation as assessed by validated questionnaire or structured interview.

Results: Depression or depressive symptom prevalence data were extracted from 167 cross-sectional studies (n = 116 628) and 16 longitudinal studies (n = 5728) from 43 countries. All but 1 study used self-report instruments. The overall pooled crude prevalence of depression or depressive symptoms was 27.2% (37 933/122 356 individuals; 95% CI, 24.7% to 29.9%, I2 = 98.9%). Summary prevalence estimates ranged across assessment modalities from 9.3% to 55.9%. Depressive symptom prevalence remained relatively constant over the period studied (baseline survey year range of 1982-2015; slope, 0.2% increase per year [95% CI, -0.2% to 0.7%]). In the 9 longitudinal studies that assessed depressive symptoms before and during medical school (n = 2432), the median absolute increase in symptoms was 13.5% (range, 0.6% to 35.3%). Prevalence estimates did not significantly differ between studies of only preclinical students and studies of only clinical students (23.7% [95% CI, 19.5% to 28.5%] vs 22.4% [95% CI, 17.6% to 28.2%]; P = .72). The percentage of medical students screening positive for depression who sought psychiatric treatment was 15.7% (110/954 individuals; 95% CI, 10.2% to 23.4%, I2 = 70.1%). Suicidal ideation prevalence data were extracted from 24 cross-sectional studies (n = 21 002) from 15 countries. All but 1 study used self-report instruments. The overall pooled crude prevalence of suicidal ideation was 11.1% (2043/21 002 individuals; 95% CI, 9.0% to 13.7%, I2 = 95.8%). Summary prevalence estimates ranged across assessment modalities from 7.4% to 24.2%.

Conclusions and relevance: In this systematic review, the summary estimate of the prevalence of depression or depressive symptoms among medical students was 27.2% and that of suicidal ideation was 11.1%. Further research is needed to identify strategies for preventing and treating these disorders in this population.

Figure 1

Study Identification and Selection

Figure 2. Meta-analysis by Scores on the Aga Khan University Anxiety and Depression Scale and the Beck Depression Inventory

The vertical dashed lines indicate the pooled summary estimate (95% CI) for all studies in Figures 2–6: 27.2% (37 933/122 356 individuals); 95% CI, 24.7%–29.9%; I² = 98.9%, τ² = 0.78, P < .001. The area of each square is proportional to the inverse variance of the estimate. Horizontal lines indicate 95% confidence intervals of the estimate. The studies in Figures 2–6 are ordered alphabetically by screening instrument and then sorted by increasing sample size within each instrument.

Figure 3. Meta-analysis by Scores on the First, Second, and Short Form Versions of the Beck Depression Inventory, Brief Symptom Inventory Depression Scale, and the Center for Epidemiological Studies Depression Scale

The vertical dashed lines indicate the pooled summary estimate (95% CI) for all studies in Figures 2–6: 27.2% (37 933/122 356 individuals); 95% CI, 24.7%–29.9%; I² = 98.9%, τ² = 0.78, P < .001. The area of each square is proportional to the inverse variance of the estimate. Horizontal lines indicate 95% confidence intervals of the estimate. The studies in Figures 2–6 are ordered alphabetically by screening instrument and then sorted by increasing sample size within each instrument.

Figure 4. Meta-analysis by Scores on the Depression Anxiety Stress Scale, Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Criteria A and C, Derogatis Stress Profile, Emotional State Questionnaire, General Depression Scale Short Form, General Health Questionnaire, and the Hospital Anxiety and Depression Scale

The vertical dashed lines indicate the pooled summary estimate (95% CI) for all studies in Figures 2–6: 27.2% (37 933/122 356 individuals); 95% CI, 24.7%–29.9%; I² = 98.9%, τ² = 0.78, P < .001. The area of each square is proportional to the inverse variance of the estimate. Horizontal lines indicate 95% confidence intervals of the estimate. The studies in Figures 2–6 are ordered alphabetically by screening instrument and then sorted by increasing sample size within each instrument.

Figure 5. Meta-analysis by Scores on Several Scales

The vertical dashed lines indicate the pooled summary estimate (95% CI) for all studies in Figures 2–6: 27.2% (37 933/122 356 individuals); 95% CI, 24.7%–29.9%; I² = 98.9%, τ² = 0.78, P < .001. The area of each square is proportional to the inverse variance of the estimate. Horizontal lines indicate 95% confidence intervals of the estimate. The studies in Figures 2–6 are ordered alphabetically by screening instrument and then sorted by increasing sample size within each instrument. DSM-IV, Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition.

Figure 6. Meta-analysis by Scores on the Patient-Reported Outcomes Measurement Information System, Quick Inventory of Depressive Symptomatology, 90-Item Symptom Checklist, Thai Depression Inventory, and the Zung Self-Rating Depression Scale

The vertical dashed lines indicate the pooled summary estimate (95% CI) for all studies in Figures 2–6: 27.2% (37 933/122 356 individuals); 95% CI, 24.7%–29.9%; I² = 98.9%, τ² = 0.78, P < .001. The area of each square is proportional to the inverse variance of the estimate. Horizontal lines indicate 95% confidence intervals of the estimate. The studies in Figures 2–6 are ordered alphabetically by screening instrument and then sorted by increasing sample size within each instrument.

Figure 7. Meta-analyses of the Prevalence of Depression or Depressive Symptoms Among Medical Students Stratified by Screening Instrument and Cutoff Score

Pooled summary estimates are ordered alphabetically by screening instrument. The individual studies contributing to each summary estimate are reported in Figures 2 through 6. The area of each diamond is proportional to the inverse variance of the estimate. Horizontal extremes of the diamonds indicate 95% CIs of the estimate.

Figure 8. Meta-analyses of the Prevalence of Depression or Depressive Symptoms Among Medical Students Stratified by Study-Level Characteristics

The area of each diamond is proportional to the inverse variance of the estimate. Horizontal extremes of the diamonds indicate 95% CIs of the estimate. ^aComparison of studies reporting only on preclinical students with those studies reporting only on clinical students.

Figure 9. Meta-analyses of the Prevalence of Depression or Depressive Symptoms Among Medical Students Stratified by Newcastle-Ottawa Scale Components and Total Score

Full details regarding Newcastle-Ottawa risk of bias scoring are provided in eMethods 2 in the Supplement. Component scores for all individual studies are presented in eTable 2 in the Supplement. The area of each diamond is proportional to the inverse variance of the estimate. Horizontal extremes of the diamonds indicate 95% CIs of the estimate.

Figure 10. Meta-analysis of the Prevalence of Suicidal Ideation Among Medical Students

Contributing studies are stratified by screening modality and sorted by increasing sample size. The dotted line marks the overall summary estimate for all studies, 11.1% (2043/21 002 individuals; 95% CI, 9.0%–13.7%; Q = 547.1, τ² = 0.32, I² = 95.8%, P < .001). The area of each square is proportional to the inverse variance of the estimate. Horizontal lines indicate 95% CIs of the estimate.