|Year : 2019 | Volume
| Issue : 4 | Page : 237-243
The prevalence rate and associations of depressive symptoms and smoking among applied medical science students in a large university in Saudi Arabia: A cross-sectional study
Eiad AlFaris1, Farhana Irfan1, Hussein Saad Amin2, Riaz Qureshi3, Nasr AlMaflehi4, Mohammed Ali Batais2, Abdullah M A. Ahmed5, Gominda Ponnamperuma6, Saira AlQahtani7, Abrar T AlTurki8, Amro K Bin Abdulrahman9, Cees van der Vleuten10, Heba AlFaris11
1 King Saud University Chair for Medical Education Research and Development; Department of Family and Community Medicine, College of Medicine, King Saud University, Riyadh, Saudi Arabia
2 Department of Family and Community Medicine, College of Medicine, King Saud University, Riyadh, Saudi Arabia
3 Department of Family Medicine, Aga Khan University Hospital, Karachi, Pakistan
4 Periodontics and Community Dentistry Department, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
5 King Saud University Chair for Medical Education Research and Development, King Saud University, Riyadh, Saudi Arabia
6 Centre for Medical Education, National University of Singapore, Singapore
7 Family Medicine Department, Ministry of Health, Riyadh, Saudi Arabia
8 Department of Pediatrics, King Saud Medical City, King Saud University, Riyadh, Saudi Arabia
9 Public Health Department, College of Medicine, Al Imam Mohammad Ibn Saud Islamic University, Riyadh, Saudi Arabia
10 Department of Educational Development and Research, Faculty of Health, Medicine and Life Sciences, School of Health Professions Education, Maastricht University, Maastricht, The Netherlands
11 Department of Surgery, King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia
|Date of Web Publication||4-Oct-2019|
Department of Family and Community Medicine, College of Medicine, King Saud University, PO Box 2925, Riyadh 11461
Source of Support: None, Conflict of Interest: None
Background: Depression among health professional students is a topic of concern. Often, it is associated with other unhealthy habits such as smoking. This study aimed to find the prevalence rate of depressive symptoms and smoking among applied medical science (AMS) students and their associations with each other. Methodology: In this descriptive-analytic, cross-sectional study, a stratified proportionate sampling strategy was used to select the study sample from the AMS school students, Saudi Arabia, during the academic year 2012–2013. The students were screened for depressive symptoms and smoking status using Beck Depression Inventory (BDI II) and a sociodemographic form, which included the smoking status. Results: The instruments were administered to 461 AMS students, representing 27.6% of the total school students (1672). Overall, 46% of the total sample (43% of males and 48% of females) had depressive symptoms. The rate of smoking currently was 11.5%, and it was much lower among female students (2.2%) as compared to their male counterparts (20.3%). There was a higher mean BDI score among current smokers compared to nonsmokers (P = 0.049). This association was statistically significant among the female students (P = 0.029) but not among the male students (P = 0.072). Conclusion: The rate of depressive symptoms in this study is alarmingly high. The association between the presence of depressive symptoms and smoking is in line with the literature on this topic. A qualitative study in this population is recommended to explore students' perception of the factors associated with smoking, depression, and stress and their coping strategies.
Keywords: Applied medical sciences students, depression, mental health, prevalence, smoking
|How to cite this article:|
AlFaris E, Irfan F, Amin HS, Qureshi R, AlMaflehi N, Batais MA, A. Ahmed AM, Ponnamperuma G, AlQahtani S, AlTurki AT, Bin Abdulrahman AK, der Vleuten Cv, AlFaris H. The prevalence rate and associations of depressive symptoms and smoking among applied medical science students in a large university in Saudi Arabia: A cross-sectional study. J Nat Sci Med 2019;2:237-43
|How to cite this URL:|
AlFaris E, Irfan F, Amin HS, Qureshi R, AlMaflehi N, Batais MA, A. Ahmed AM, Ponnamperuma G, AlQahtani S, AlTurki AT, Bin Abdulrahman AK, der Vleuten Cv, AlFaris H. The prevalence rate and associations of depressive symptoms and smoking among applied medical science students in a large university in Saudi Arabia: A cross-sectional study. J Nat Sci Med [serial online] 2019 [cited 2022 Jan 21];2:237-43. Available from: https://www.jnsmonline.org/text.asp?2019/2/4/237/260448
| Introduction|| |
With the increasing demands and high expectations of today's life, anxiety and depression are becoming a common occurrence., Psychological illnesses among students were found to negatively influence not only their well-being and academic achievement but also patient care.,,
Depression is the most common mental health problem seen among health professional (HP) students , and is on the rise. Women, in general, are more susceptible to depression than men. Studies have found that the prevalence of depressive symptoms among health science students was higher among female students and in early academic years.,, With the rapid academic and environmental changes and academic competitiveness, it is expected that the students will have this trend., Hojat and Lyons  have reported that stressful life events adversely influence both the general health and the mood of applied medical sciences (AMS) students, thus increasing the prevalence of depression, loneliness, and anxiety among these students, when compared to their counterparts in other HPs. Furthermore, students with psychological symptoms may resort to inappropriate health behaviors such as smoking.
Smoking has been found to be strongly associated with stress, anxiety, and depression.,,, A recent systematic review of 148 studies found an association in both directions (smoking to later mental health and mental health to later smoking), with about half of the studies indicating that smoking precedes depression, while a third of the studies indicating that smoking is preceded by depression. This is in line with the other reported studies., However, recent results from Mendelian randomization analyses do not show a causal role of smoking heaviness in the development of anxiety and depression.
At present, the Arab world is facing a tobacco epidemic and a dramatic increase in smoking levels and tobacco-related morbidity and mortality. According to the WHO report on the global tobacco epidemic, 2017, the prevalence of cigarette smoking among youth in Saudi Arabia was 8.0% (male = 13%, female = 5%). A study among Saudi youth on smoking revealed an overall smoking prevalence of 14.5% (32.7% of male and 5.9% of female university students).
The studies in Saudi Arabia have focused more on the prevalence and explored the knowledge, attitudes, and beliefs of smokers among Saudi school and university students. However, the relationship of smoking to well-being has not been explored much. A study done on a similar relationship in the late nineties reported a higher rate of depression (11%) among smokers (male 28%, female 5%). In general, the females are consuming less cigarettes, probably due to cultural reasons. An increasing trend is seen which could be due to the influence of advertisement, peer pressure, imitation, enhancing the social status, and to relieve pressure or anxiety.
Most of the previous international studies in the literature that have investigated the association between smoking and depression have focused on the youth or patients, and only very few were conducted among HP students.,,,, Only a limited number of studies has investigated the association of smoking status with depressive symptoms among HP students and among AMS students in particular. Hence, this study aimed to determine the prevalence of depressive symptoms among Saudi AMS university students and its relation with smoking.
Aim and hypotheses of this study
The main aim of the present study was to explore the association between the presence of depressive symptoms and smoking status among AMS students. Other secondary aims were to estimate the rate of current smokers with significant depressive symptoms. The following hypothesis was made: current smoking is an indicator of depression.
| Methodology|| |
This was a cross-sectional, descriptive study.
Setting of the study
The study targeted students of all academic years and both sexes attending the School of AMS at King Saud University (KSU), Riyadh, Kingdom of Saudi Arabia, during the academic year 2012–2013. Like other Saudi undergraduate HP schools, KSU operates on a single-gender basis (i.e., teaches the two genders separately). The school students are almost all of Saudi nationality (a homogenous set of students with similar ethnicity and cultural backgrounds). Students receive a monthly financial stipend (267 USD), and they do not pay university fees or tuition. The chance of getting enrolled to the school once they finish secondary school does not differ by sex or marital status.
The AMS school in the KSU has 12 specialties such as radiological science, clinical laboratory technology, physiotherapy, optometry, speech therapy, and clinical nutrition. The curriculum starts with a preparatory year, followed by 3 years in the selected field and then 1 year of internship. The 1st (preparatory) year consists of an intensive English course and general sciences such as organic chemistry and biostatistics. Each specialty has its own subjects although there are common subjects such as computer technology, physics, statistics, and communication skills. Teaching during this period is mostly didactic and practical courses with little clinical exposure. After graduation, the AMS graduates are either employed as technologists in the hospital or teaching assistants in the university.
Based on a previous study findings, which indicate that the prevalence of depressive symptoms was estimated to be 30% ± 3%, with a confidence level of 95% and a margin of error of 5%, the RaoSoft website was used to estimate the required sample size for the population of 1672 AMS students. The minimum required sample size was estimated to be 313. To overcome the expected nonresponse rate and to have a reasonable number from the different subgroups (e.g., sex and academic year), 568 students (a higher number) were invited to participate in the study.
Stratified random sampling strategy using a proportional allocation method was used to determine the number of students, based on the students' year of study and sex. Microsoft Excel program was used to randomly select the study sample within each year and sex after getting the list of students' names in each year and sex.
A short, self-administered, demographic questionnaire (with five items) was administered to the students to gather information about their age, sex, marital status, college, year of study, and smoking status. Participants were asked whether they ever smoke. Those who responded “no” were termed as “never smokers.” Only those who answered “yes” were asked to respond to the second question, “Do you currently smoke?” They were given three options: daily, some days, and never. According to the National Health Interview Survey, those who responded as smoking cigarettes every day or some days were termed as “current smokers.” Similarly, a “nonsmoker” was defined as an adult who was not currently smoking cigarettes. The consumption of other types of nicotinic substances was not considered in this study.
The Beck Depression Inventory II (BDI-II) was administered at the same time. Participation was voluntary. Informed verbal consent was obtained from the students, and anonymity and information confidentiality were assured. Furthermore, to maintain anonymity, no written documentation that could link the participant to the research study was used. The Institutional Review Board of the College of Medicine approved this method of consent (Reference no. 11/3106/IRB).
Beck Depression Inventory II
This is a 21-question multiple-choice self-report inventory, one of the most widely used psychometric tests for measuring the severity of depression, with four response options ranging from 0 to 3 for each item. The total maximum score for all items thus is 63. A score of 0–13 is considered minimal, 14–19 mild, 20–28 moderate, and 29–63 severe depression; scores >13 are considered significant depressive symptoms. The BDI-II is a psychometric instrument that measures depression, with broad applicability worldwide in both research and clinical practice., It was selected because of its wide use, specificity, and sensitivity at detecting depression among university students, high reliability, and improved concurrent and content validity based on available psychometric evidence.
Validation of the Arabic version
The original (English) BDI-II was translated into Arabic by two Arab psychiatrists. The validity of the Arabic version was checked with a back-translation into English by another psychiatrist who had no knowledge of the instrument. The translation and the back-translation were found to be in close agreement. Furthermore, it was in close agreement with psychometric study on Beck Depression Scale.
Based on the recommendations of the Vice Dean of the school, a group of trustworthy students referred to hereafter as team leaders (TLs) was invited to participate in the data collection. All of them were inspired to be diligent and honest in a training session.
TLs were assigned on the ratio of one TL for each 25–30 students and were awarded a financial incentive (500 SR = 133 US$) once they performed their assigned tasks properly and efficiently. The selected research students were informed by the TL about the required details before filling out the questionnaires.
The instrument (demographic and BDI II questionnaires in printed format) along with a cover letter, highlighting the aims and objectives of the study, was distributed to the selected students, and students returned the completed questionnaires either immediately or 1 day later.
BDI-II scores and demographic data were entered into SPSS Statistical Package for the Social Sciences IBM (SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp., USA). Descriptive statistics along with Chi-square test (after checking the cell count fit), Student's t-test, and ANOVA were performed to compare the prevalence of depressive symptoms with the students' sociodemographic factors (i.e., sex and year of study) and also with their smoking status. P < 0.05 was considered statistically significant.
| Results|| |
Of the 568 AMS students who were approached, 460 completed the questionnaire (response rate 81%). A lower response rate was found among the 1st- and 5th- year students. The reliability coefficient (Cronbach's alpha) of the BDI-II scores was 0.83.
The sex distribution of the sample was 51% males and 49% females [Table 1]. The mean age of the students was 21.04 ± 1.55 years.
|Table 1: Sociodemographic characteristics of applied medical science students (n=460) and their association with the rate and severity of depression|
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The mean BDI-II score for the whole study sample was found to be 14 (standard deviation = 8.52), and it was higher for female students (14.208) than their male counterparts (13.33). However, the difference was not statistically significant (P = 0.265) [Table 1].
Although not statistically significant, the rate of total depressive symptoms was highest among the 5th-year (53.8%) and the 1st-year students (52.6%) and was lowest (38.7%) among the 4th-year students [Table 2].
|Table 2: Association between year of study and severity of depressive symptoms among applied medical science students|
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The rate of current smokers was 11.5%, and it was much lower among female students (2.2%) compared to their male counterparts (20.3%). There was a statistically significant higher severity of depressive symptoms (as reflected by the mean BDI-II score) among those who were current smokers (15.94) compared with those who were nonsmokers (13.42) (P < 0.049). It was, however, only true for the female students (BDI-II mean score 22.40 versus 14.02) (P < 0. 029) but not for the male students [Table 3].
|Table 3: Association between smoking status and the Beck Depression Inventory mean scores for all the male and female applied medical science students|
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| Discussion|| |
In line with the previous studies, the current study found an association between the severity of depressive symptoms of AMS students and their smoking status. Although an alarming rate (46%) of depressive symptoms among AMS students was found, the rate of current smokers (11.5%) was relatively low.
Depressive symptoms versus smoking
The current study found a positive association between the severity of depressive symptoms and smoking. Most of the studies that investigated the association between depressive symptoms and smoking were conducted among the youth and patients,,,, and only a few were conducted among the university students. All the studies among university students found a positive association between the severity of depressive symptoms and smoking., For example, a Nigerian study, among university students with an odds ratio of 3.67. The incentive learning theory suggests that adverse internal states are the primary drivers which function as motivational states of smoking behavior among depressed individuals. This could provide an explanation for the relationship between smoking and depression observed in the current study.
As the current study is cross-sectional study, causality in either direction (depressive symptoms causing smoking or smoking leading to depressive symptoms) cannot be claimed. It indicates a higher likelihood of depressive symptoms among university students who smoke compared to their nonsmoking counterparts. The desire to smoke in this age group is probably prompted by unfavorable internal or external states such as depression.
Moreover, the depressive symptoms among female nonsmoking students were significantly less severe compared to the current smokers. Literature has shown a connection between sex and smoking status. It is reported that adolescent and adult females have greater smoking–depression relationship than their male counterparts.,,, However, some other studies showed an increased risk of depression among male, but not female, smokers.,, Gritz et al. explained that cigarette smoking prevalence differs by ethnicity, culture, and gender-specific effects on the smoking–depression relationship is complex and remains incompletely understood. Kassel et al. suggested that smoking–depression relationship requires investigation through a transdisciplinary, contextual lens to increase our understanding of the processes involved.
The current study represents an important geographical extension to the scope of previous research by reinforcing that smoking among college students is associated with a greater likelihood of depressive symptoms. The reason could be psychological states (e.g., depression) provoking smoking or vice versa.
Prevalence of depressive symptoms
Compared to the high prevalence rate of depressive symptoms reported in this study, the prevalence rate has been variable in other studies among medical students ranging from 12% in the USA and Canada  and 47.0% in Saudi Arabia. On the other hand, studies in the other health specialties found a figure of 21% among physiotherapy students in India, 25% for chiropractic students in Canada, 44% among nursing students in Greece, and 51% among pharmacy students in Egypt.
The use of different instruments to assess the rate of depressive symptoms, such as the BDI-II versus the Center for Epidemiological Studies Depression 10 scale, could in part explain these different figures. Cultural issues such as low sense of control, economic factors, and income inequalities were found to be associated with the rate of depressive symptoms. In an earlier study, among medical students in Saudi Arabia, the conventional curriculum students were found to have a higher rate of depressive symptoms than their system-based counterparts.
The higher prevalence of depressive symptoms among females (though statistically not significant) is in line with some reports,, and not so with some other cross-sectional ,, and longitudinal studies., The highest rate of depressive symptoms among the final-year students is in line with the findings of other studies cited in the literature. It could be attributed to difficulty in making career choices, as well as a concern and a lack of self-confidence on fitness and competence for future clinical practice.,
Literature suggests that students with depressive symptoms may maintain or restart smoking to cope with stress. This is more likely to happen among students who lack healthy coping mechanisms and mood management techniques. They may resort to unhealthy coping mechanisms such as smoking. Cognitive-behavioral therapy interventions may help smoking cessation as well as the depressive symptoms.
Therefore, screening for depression for this population is probably worthwhile to combat the negative consequences and unhealthy coping behaviors. Student-centered curriculum and academic counseling facilities for students in educational or psychosocial difficulties are probably needed.
Prevalence of smoking
The rate of current smokers in the current study (11.5%) is relatively low when compared to university students from South European countries: male and female students in Greece (44% vs. 42%), Italy (43% vs. 35%), and Portugal (47% vs. 42) but comparable to developing countries such as Thailand (14% vs. 2%) and South Africa (15% vs. 4%).
Strengths and limitations
The current study gathered data on depressive symptoms of AMS students, using a validated inventory. To the best of our knowledge, it is one of the very few studies that tested the relationship between smoking and depression among AMS students. Therefore, the results of this study can serve as a reference for future prospective studies in the field of student well-being. The stratified proportionate sampling strategy is another strength, vouching for the validity of the study results.
However, the study is not without limitations. It was conducted in one school and therefore may not be generalizable for other AMS students' population. The use of self-administered inventory (the BDI inventory) identifies depressive symptoms rather than actual clinical depression. Furthermore, a cause–effect relationship cannot be established based on the findings of this study since it is of cross-sectional design.
The lower response rate among the 1st- and 5th- year students is probably due to the coincidence of the data collection period being near their examinations.
| Conclusion|| |
Smoking among AMS students in a large university was found to be associated with a higher severity of depressive symptoms and therefore could be looked at as an alarm to screen for depression and support if needed.
Further exploratory research is needed to verify the association between smoking and depression and the strategies needed for the elimination of school-related causes of depression and possibly smoking.
We gratefully acknowledge the students who participated in this study and the administration at the Applied Medical Science College who helped collect data for this study.
Financial support and sponsorship
This work was financially supported by the Deanship of Scientific Research, King Saud University, for funding through Vice Deanship of Scientific Research Chairs.
Conflicts of interest
There are no conflicts of interest.
| References|| |
Turner DP, Thompson ME, Huber LR, Arif AA. Depressive symptoms and academic performance of North Carolina college students. N C Med J 2012;73:169-75.
Dyrbye LN, Thomas MR, Shanafelt TD. Systematic review of depression, anxiety, and other indicators of psychological distress among US and Canadian medical students. Acad Med 2006;81:354-73.
Dahlin ME, Runeson B. Burnout and psychiatric morbidity among medical students entering clinical training: A three year prospective questionnaire and interview-based study. BMC Med Educ 2007;7:6.
Sabih F, Siddiqui FR, Baber MN. Assessment of stress among physiotherapy students at Riphah centre of rehabilitation sciences. J Pak Med Assoc 2013;63:346-9.
Beiter R, Nash R, McCrady M, Rhoades D, Linscomb M, Clarahan M, et al.
The prevalence and correlates of depression, anxiety, and stress in a sample of college students. J Affect Disord 2015;173:90-6.
Aktekin M, Karaman T, Senol YY, Erdem S, Erengin H, Akaydin M, et al.
Anxiety, depression and stressful life events among medical students: A prospective study in Antalya, Turkey. Med Educ 2001;35:12-7.
Phimarn W, Kaewphila P, Suttajit S, Saramunee K. Depression screening and advisory service provided by community pharmacist for depressive students in university. Springerplus 2015;4:470.
Wahed WY, Hassan SK. Prevalence and associated factors of stress, anxiety and depression among medical Fayoum University students. [published online February 20, 2016]. Alex J Med 2016. doi:10.1016/j.ajme.2016.01.005.
Al-Faris EA, Irfan F, Van der Vleuten CP, Naeem N, Alsalem A, Alamiri N, et al
. The prevalence and correlates of depressive symptoms from an Arabian setting: A wake up call. Med Teach 2012;34 Suppl 1:S32-6.
Dyrbye LN, Thomas MR, Shanafelt TD. Medical student distress: Causes, consequences, and proposed solutions. Mayo Clin Proc 2005;80:1613-22.
Al-Mulhim AA, Al-Kuwaiti A. The future of the curriculum of allied (applied) health sciences in Saudi Arabia. J Family Community Med 2002;9:55-9.
Hojat M, Lyons K. Psychosocial characteristics of female students in the allied health and medical colleges: Psychometrics of the measures and personality profiles. Adv Health Sci Educ Theory Pract 1998;3:119-32.
Adewuya AO, Ola BA, Aloba OO, Mapayi BM, Oginni OO. Depression amongst Nigerian university students. Prevalence and sociodemographic correlates. Soc Psychiatry Psychiatr Epidemiol 2006;41:674-8.
Taylor AE, Fluharty ME, Bjørngaard JH, Gabrielsen ME, Skorpen F, Marioni RE, et al
. Investigating the possible causal association of smoking with depression and anxiety using Mendelian randomisation meta-analysis: The CARTA consortium. BMJ Open 2014;4:e006141.
Al-Subaie AS. Smoking and Its relationship to depression and anxiety among Saudi University students. Int J Ment Health 1998;27:3, 86-95.
Chaiton MO, Cohen JE, O'Loughlin J, Rehm J. A systematic review of longitudinal studies on the association between depression and smoking in adolescents. BMC Public Health 2009;9:356.
Audrain-McGovern J, Rodriguez D, Rodgers K, Cuevas J. Declining alternative reinforcers link depression to young adult smoking. Addiction 2011;106:178-87.
Fluharty M, Taylor AE, Grabski M, Munafò MR. The association of cigarette smoking with depression and anxiety: A systematic review. Nicotine Tob Res 2017;19:3-13.
Trosclair A, Dube SR. Smoking among adults reporting lifetime depression, anxiety, anxiety with depression, and major depressive episode, United States, 2005-2006. Addict Behav 2010;35:438-43.
Mojtabai R, Crum RM. Cigarette smoking and onset of mood and anxiety disorders. Am J Public Health 2013;103:1656-65.
Maziak W, Nakkash R, Bahelah R, Husseini A, Fanous N, Eissenberg T, et al
. Tobacco in the Arab world: Old and new epidemics amidst policy paralysis. Health Policy Plan 2014;29:784-94.
Ajoud ME. Factors of smoking among Saudi Youth in the Northern Border Region. J Soc Welfare and Hum Rights 2013;1:22-35.
Ansari K, Farooqi FA. Comparison and prevalence of smoking among Saudi females from different departments of the college of applied medical sciences in Dammam. Int J Health Sci (Qassim) 2017;11:56-62.
Ibrahim AK, Kelly SJ, Adams CE, Glazebrook C. A systematic review of studies of depression prevalence in university students. J Psychiatr Res 2013;47:391-400.
Ryan H, Trosclair A, Gfroerer J. Adult current smoking: Differences in definitions and prevalence estimates – NHIS and NSDUH, 2008. J Environ Public Health 2012;2012:11.
Beck AT, Steer RA, Brown GK. Manual for Beck Depression Inventory-II. San Antonio, TX: The Psychological Corporation; 1996.
Beck AT, Ward CH, Mendelson M, Mock J, Erbaugh J. An inventory for measuring depression. Arch Gen Psychiatry 1961;4:561-71.
Wang YP, Gorenstein C. Psychometric properties of the beck depression inventory-II: A comprehensive review. Braz J Psychiatry 2013;35:416-31.
Storch EA, Roberti JW, Roth DA. Factor structure, concurrent validity, and internal consistency of the beck depression inventory-second edition in a sample of college students. Depress Anxiety 2004;19:187-9.
Munafò MR, Araya R. Cigarette smoking and depression: A question of causation. Br J Psychiatry 2010;196:425-6.
Pesko MF. Stress and smoking: Associations with terrorism and causal impact. Contemp Econ Policy 2014;32:351-71.
Mathew AR, Hogarth L, Leventhal AM, Cook JW, Hitsman B. Cigarette smoking and depression comorbidity: Systematic review and proposed theoretical model. Addiction 2017;112:401-12.
Goodman E, Capitman J. Depressive symptoms and cigarette smoking among teens. Pediatrics 2000;106:748-55.
Steuber TL, Danner F. Adolescent smoking and depression: Which comes first? Addict Behav 2006;31:133-6.
Massak A, Graham K. Is the smoking-depression relationship confounded by alcohol consumption? An analysis by gender. Nicotine Tob Res 2008;10:1231-43.
Husky MM, Mazure CM, Paliwal P, McKee SA. Gender differences in the comorbidity of smoking behavior and major depression. Drug Alcohol Depend 2008;93:176-9.
Wang Y, Browne DC, Storr CL, Wagner FA. Gender and the tobacco-depression relationship: A sample of African American college students at a historically black college or university (HBCU). Addict Behav 2005;30:1437-41.
Mykletun A, Overland S, Aar Leif E, Liab HM, Stewart R. Smoking in relation to anxiety and depression: Evidence from a large population survey: The HUNT study. Eur Psychiatry 2008;23:77-84.
Korhonen T, Broms U, Varjonen J, Romanov K, Koskenvuo M, Kinnunen T, et al.
Smoking behaviour as a predictor of depression among Finnish men and women: A prospective cohort study of adult twins. Psychol Med 2007;37:705-15.
Gritz ER, Prokhorov AV, Hudmon KS, Chamberlain RM, Taylor WC, DiClemente CC, et al.
Cigarette smoking in a multiethnic population of youth: Methods and baseline findings. Prev Med 1998;27:365-84.
Kassel JD, Stroud LR, Paronis CA. Smoking, stress, and negative affect: Correlation, causation, and context across stages of smoking. Psychol Bull 2003;129:270-304.
AlFaris E, Irfan F, Qureshi R, Naeem N, Alshomrani A, Ponnamperuma G, et al.
Health professions' students have an alarming prevalence of depressive symptoms: Exploration of the associated factors. BMC Med Educ 2016;16:279.
Gunase KN, Mubeen G, Ronika A. Prevalence study of depression among physiotherapy students in Pune. Int J Contemp Med 2015;3:93-7. [doi: 10.5958/2321-1032.2015.00021.2].
Kinsinger S, Puhl AA, Reinhart CJ. Depressive symptoms in chiropractic students: A 3-year study. J Chiropr Educ 2011;25:142-50.
Melissa-Halikiopoulou C, Tsiga E, Khachatryan R, Papazisis G. Suicidality and depressive symptoms among nursing students in Northern Greece. Health Sci J 2011;5:90-7.
Ibrahim MB, Abdelreheem MH. Prevalence of anxiety and depression among medical and pharmaceutical students in Alexandria. Univ Alex J Med 2015;51:167-73.
Steptoe A, Tsuda A, Tanaka Y, Wardle J. Depressive symptoms, socio-economic background, sense of control, and cultural factors in university students from 23 countries. Int J Behav Med 2007;14:97-107.
AlFaris EA, Naeem N, Irfan F, Qureshi R, van der Vleuten C. Student centered curricular elements are associated with a healthier educational environment and lower depressive symptoms in medical students. BMC Med Educ 2014;14:192.
Buchman BP, Sallis JF, Criqui MH, Dimsdale JE, Kaplan RM. Physical activity, physical fitness, and psychological characteristics of medical students. J Psychosom Res 1991;35:197-208.
Tjia J, Givens JL, Shea JA. Factors associated with undertreatment of medical student depression. J Am Coll Health 2005;53:219-24.
Hojat M, Glaser K, Xu G, Veloski JJ, Christian EB. Gender comparisons of medical students' psychosocial profiles. Med Educ 1999;33:342-9.
Clark DC, Zeldow PB. Vicissitudes of depressed mood during four years of medical school. JAMA 1988;260:2521-8.
Richman JA, Flaherty JA. Gender differences in medical student distress: Contributions of prior socialization and current role-related stress. Soc Sci Med 1990;30:777-87.
Madhyastha S, Latha KS, Kamath A. Stress and coping among final year medical students. AP J Psychol Med 2014;15:74-80.
Dahlin M, Joneborg N, Runeson B. Stress and depression among medical students: A cross-sectional study. Med Educ 2005;39:594-604.
Schleicher HE, Harris KJ, Campbell DG, Harrar SW. Mood management intervention for college smokers with elevated depressive symptoms: A pilot study. J Am Coll Health 2012;60:37-45.
Carlson MD, Morrison RS. Study design, precision, and validity in observational studies. J Palliat Med 2009;12:77-82.
[Table 1], [Table 2], [Table 3]