Prevalence of Depression and Depressive Symptoms Among Resident Physicians: A Systematic Review and Meta-analysis

Abstract

Importance: Physicians in training are at high risk for depression. However, the estimated prevalence of this disorder varies substantially between studies.

Objective: To provide a summary estimate of depression or depressive symptom prevalence among resident physicians.

Data sources and study selection: Systematic search of EMBASE, ERIC, MEDLINE, and PsycINFO for studies with information on the prevalence of depression or depressive symptoms among resident physicians published between January 1963 and September 2015. Studies were eligible for inclusion if they were published in the peer-reviewed literature and used a validated method to assess for depression or depressive symptoms.

Data extraction and synthesis: Information on study characteristics and depression or depressive symptom prevalence was extracted independently by 2 trained investigators. Estimates were pooled using random-effects meta-analysis. Differences by study-level characteristics were estimated using meta-regression.

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

Results: Data were extracted from 31 cross-sectional studies (9447 individuals) and 23 longitudinal studies (8113 individuals). Three studies used clinical interviews and 51 used self-report instruments. The overall pooled prevalence of depression or depressive symptoms was 28.8% (4969/17,560 individuals, 95% CI, 25.3%-32.5%), with high between-study heterogeneity (Q = 1247, τ2 = 0.39, I2 = 95.8%, P < .001). Prevalence estimates ranged from 20.9% for the 9-item Patient Health Questionnaire with a cutoff of 10 or more (741/3577 individuals, 95% CI, 17.5%-24.7%, Q = 14.4, τ2 = 0.04, I2 = 79.2%) to 43.2% for the 2-item PRIME-MD (1349/2891 individuals, 95% CI, 37.6%-49.0%, Q = 45.6, τ2 = 0.09, I2 = 84.6%). There was an increased prevalence with increasing calendar year (slope = 0.5% increase per year, adjusted for assessment modality; 95% CI, 0.03%-0.9%, P = .04). In a secondary analysis of 7 longitudinal studies, the median absolute increase in depressive symptoms with the onset of residency training was 15.8% (range, 0.3%-26.3%; relative risk, 4.5). No statistically significant differences were observed between cross-sectional vs longitudinal studies, studies of only interns vs only upper-level residents, or studies of nonsurgical vs both nonsurgical and surgical residents.

Conclusions and relevance: In this systematic review, the summary estimate of the prevalence of depression or depressive symptoms among resident physicians was 28.8%, ranging from 20.9% to 43.2% depending on the instrument used, and increased with calendar year. Further research is needed to identify effective strategies for preventing and treating depression among physicians in training.

Figure 1. Flow Diagram for Identifying Studies on the Prevalence of Depression or Depressive Symptoms Among Resident Physicians

All studies identified by hand searching reference lists were found in the database search. For simplicity, this number is not duplicated in the diagram.

Figure 2. Meta-analysis of the Prevalence of Depression or Depressive Symptoms Among Resident Physicians

Contributing studies are stratified by screening modality and ordered by increasing sample size. The area of each square is proportional to the inverse variance of the estimate. The dotted line marks the overall summary estimate for all studies, 28.8% (4969/17 560 individuals, 95% CI, 25.3%-32.5%, Q = 1247.11, τ² = 0.39, I² = 95.8% [95% CI, 95.0%-96.4%], P < .001). (Refer to footnotes of Table 1 and Table 2 for expanded names of diagnostic instruments.)

Figure 3. Meta-analyses of the Prevalence of Depressive Symptoms Among Resident Physicians in Subsets of Studies Stratified by Screening Modality and Cutoff Score

The area of each diamond is proportional to the inverse variance of the estimate. BDI indicates Beck Depression Inventory; CES-D, Center for Epidemiologic Studies Depression Scale; HANDS, Harvard Department of Psychiatry/National Depression Screening Day Scale; PHQ-9, 9-item Patient Health Questionnaire; PRIME-MD, 2-item Primary Care Evaluation of Mental Disorders questionnaire; Zung SDS, Zung Self-rating Depression Scale.

Figure 4. Meta-analyses of the Prevalence of Depression or Depressive Symptoms Among Resident Physicians Stratified by Study-Level Characteristics

The area of each diamond is proportional to the inverse variance of the estimate.

Figure 5. Meta-analyses of the Prevalence of Depression or Depressive Symptoms Among Resident Physicians Stratified by Newcastle-Ottawa Scale Components and by Total Score

The area of each diamond is proportional to the inverse variance of the estimate.