Medical student depression and its correlates across three international medical schools

Table 1 Chi-square and analysis of variance comparisons of group characteristics

Variable	Yale University School of Medicine, n = 205	Middle Eastern Medical School, n = 126	Xiangya School of Medicine, n = 142	Entire population, n = 473	Statistics
Age, mean (SD1)	25.3 (2.4)	22.1 (1.0)	22.0 (1.5)	23.4 (2.5)	F = 174.7a
Gender	43.4% Male (M) 56.6% Female (F)	37.3% M 62.7% F	43.7% M 56.3% F	41.8% M 58.2% F	χ2 = 0.5
Sleep2 in hr, mean (SD)	6.6 (1.0)	6.6 (1.0)	6.5 (0.9)	6.5 (1.0)	F = 5.6a
Exercise3, mean (SD)	2.5 (1.8)	1.4 (1.7)	1.6 (1.8)	1.9 (1.8)	F = 18.1a
Depression screening by PHQ-24 category	Not depressed: 62.8% Mild depression: 33.3% Depressed: 3.8% (n = 7)	Not depressed:10.5% Mild depression: 48.8% Depressed: 41.1% (n = 51)	Not depressed: 16.2 % Mild depression: 69.7% Depressed: 14.1% (n = 20)	Not depressed: 33.6% Mild depression: 49.0% Depressed: 17.4% (n = 78)	χ2 = 161.1a
Stress5	Yes: 58.4% (n = 108)	Yes: 75.4% (n = 95)	Yes: 82.9% (n = 116)	Yes=70.9% (n = 319)	χ2 = 25.3a
Unmet mental health need6	Disagree: 49.5% Neutral: 17.7% Agree: 32.8%	Disagree: 32.5% Neutral: 16.7% Agree: 50.8%	Disagree: 47.1% Neutral: 18.1% Agree: 34.8%	Disagree: 44.1% Neutral: 17.6% Agree: 38.3%	χ2 = 12.1b

^aP < 0.01;

^bP < 0.05;

¹SD: Standard deviation;

²For the purposes of scale measurement, if a participant answered < 4 h a night, 3.5 was the number coded, 4-5 h a night = 4.5; 6-7 h a night = 6.5, and > 8 h a night was coded as 8.5;

³Mean number of days per week spent exercising at least 30 consecutive minutes;

⁴PHQ-2: Patient Health Questionnaire-2; where not depressed = 0, mild depression is 1-2, depressed is ≥ 3;

⁵Response to question “Are you stressed?”;

⁶Answer of agreement to Likert scale question “there are times I have a mental health need for which I do not seek care”. Agree and Strongly Disagree were collapsed into one category; Agree and Strongly Agree were collapsed into another.

Table 2 Comparison of samples of medical students on depression (ANCOVA)¹

Over the past 2 wk, how often have you been bothered by any of the following problems? (PHQ-22)	a United States	b Middle Eastern country	c China	Paired comparison
	LS mean (SE)	LS mean (SE)	LS mean (SE)
1 Little interest or pleasure in doing things	0.37 (0.05)	1.18 (0.06)	0.92 (0.06)	b > a, c; c > a
2 Feeling down, depressed or hopeless	0.36 (0.05)	1.07 (0.06)	0.76 (0.05)	b > a, c; c > a
Total Score	0.73 (0.08)	2.25 (0.10)	1.68 (0.09)	b > a, c; c > a

¹Adjusted for differences in unmet mental health needs;

²PHQ-2: Patient Health Questionnaire-2; where not depressed = 0, mild depression is 1-2, depressed is ≥ 3. LS mean: Least square mean; SE: Standard error.

Table 3 Comparison of samples of medical students on emotional exhaustion (ANCOVA)¹

Survey items	a United States	b Middle Eastern country	c China	Paired comparison
	LS mean (SE)	LS mean (SE)	LS mean (SE)
I feel emotionally drained by my studies.	2.82 (0.07)	1.92 (0.08)	2.31 (0.07)	a > b, c; c > b
I feel used up at the end of a day in medical school.	3.44 (0.08)	3.05 (0.10)	2.84 (0.08)	a > b, c
I feel burned out from my studies.	2.83 (0.07)	2.81 (0.09)	2.41 (0.08)	a > c, b > c
I have become less interested in my studies since my enrollment in medical school.	2.51 (0.08)	2.40 (0.10)	2.07 (0.09)	a > c, b > c
Emotional exhaustion component	2.90 (0.05)	2.55 (0.07)	2.42 (0.06)	a > b, c

¹Adjusted for differences in Patient Health Questionnaire-2 total score. LS mean: Least square mean; SE: Standard error.

Table 4 Multiple linear regression on medical student depression measured by patient health questionnaire-2 in response to demographic, behavioral and psychological variables

Predictor variables	R2	Adjusted R2	F	Significance	B	Std. Error	β	t
Model	0.473	0.461	41.621	P < 0.001
Age					0.025	0.027	0.043	0.906
Male					-0.089	0.101	-0.032	-0.881
Sleep					0.006	0.105	0.002	0.055
Exercisea					-0.120	0.044	-0.103	-2.756
Unmet mental health needsa					0.235	0.041	0.228	5.780
Emotional exhaustiona					0.496	0.072	0.271	6.903
Stress					-0.264	0.122	-0.086	-2.155
Middle Eastern countrya					1.477	0.157	0.475	9.439
Chinaa					1.005	0.155	0.338	6.492

^aP < 0.01. Associated changes in R² for the following independent variable last added into the model, as its unique contribution to the improvement in the model’s goodness-of-fit: Exercise: 0.01; Unmet mental health needs: 0.045; Emotional Exhaustion: 0.061; Stress: 0.006; Middle Eastern country: 0.113; China: 0.054