Spectrum of Anxiety Disorders Among Medical Students in a Nigerian Medical School : A Cross-Sectional Study With Standardized Screening Tools

Background: Anxiety disorders among medical students constitute a global problem, and also reflect the mental state of the general population. There is paucity of data on the spectrum of such disorders among medical students in Nigeria. Aim: The study aims to determine the prevalence of anxiety disorders among medical students, and the effect of socio-demographic characteristics. Methods: A total of 217 medical students from the second to the final years of study at Enugu State University of Science and Technology in south-east Nigeria were enrolled by simple random sampling. Five pretested, selfadministered standardized questionnaires were used as screening tools for anxiety disorders. Data were analyzed using the Statistical Package for Social Sciences program (SPSS version 20). A p-value less than 0.05 was taken as statistically significant. Results: Thirty one (14.3%) of the enrolled medical students fulfilled the screening criteria for anxiety disorders. Specifically, generalized anxiety disorder (GAD) was significantly related to gender (p =0.017) and the year of study (p =0.017). Post-traumatic stress disorder (PTSD) was significantly related to the year of study (p =0.037), and social anxiety disorder (SAD) to the year of study (p =0.003) and gender (p =0.04). Similarly, panic disorder was significantly related to the year of study (p =0.025) while specific phobia was significantly associated with marital status (p =0.003), parental monthly income (p =0.022) and student’s monthly allowance (p =0.002). Finally, obsessive-compulsive disorder was significantly related to marital status (p =0.034) and year of study (p =0.028). Conclusion: Medical students in Nigeria are prone to a spectrum of anxiety disorders. This susceptibility is influenced by socio-demographic characteristics.


Introduction
The medical student is constantly at risk of physical and psychological stress given the rigorous training programs and didactic syllabus (Bostanci et al., 2005).Constant perturbation of this individual with stressors may result in anxiety disorders.Short-term and long-term sequelae of these disorders include additional stress and anxiety, worsening academic performance, psychological or emotional impairment during professional life (which may affect quality of patient care), as well as depression and substance abuse (Gill & Mohammed, 2010).
Anxiety disorders among medical students remain a global challenge, which also reflect the mental state of the general population (Bostanci et al., 2005;Wittchen, 2002).Reports indicate that these disorders are particularly observed in the students' first academic year (Eller et al., 2006;Wittchen, 2002), and are attributed to academic stressors stemming from curriculum overload, paucity of leisure time and uncertainties which arise from the transit time between secondary school and first year in the university (Eller et al., 2006;Wittchen, 2002).
SAD normally occur during communication skills-based examinations or workshops such as viva voce and clinical presentation (Laidlaw, 2009).PTSD develop following a stressful event of an exceptionally threatening or catastrophic nature (Merikangas, 2004).For medical students, PTSD usually occur after failing a medical examination or when withdrawn from the school after examination failure.In addition, they are prone to developing depression with the attendant consequences to their emotional, mental and physical well-being (Tabalipa et al., 2018).
There is paucity of data on the spectrum of anxiety disorders among medical students in Nigeria.Thus, the present study aims to determine the prevalence of anxiety disorders among these students in this clime, and the effect of socio-demographic characteristics.

Study Design
This was a cross-sectional study which assessed the spectrum of anxiety disorders among medical students who attended Enugu State University of Technology Teaching Hospital in Enugu metropolis, south-east Nigeria.The study was conducted during the examination-free period in the University to minimize the effect of bias as much as possible.

Study Population
The study was carried out among medical students from second to the final year of academic study who gave their consent after explaining the optional nature of their participation and the liberty to withdraw from the study at any point.The first-year students (who were off-campus) and other students who failed to give consent were excluded.Questionnaires were administered to these students from Jan 2016 to July 2016.Socioeconomic class was assigned to the students using a method modified by Oyedeji (1985).

Questionnaire-Based Screening Tools
Five questionnaires were used to screen for the spectrum of anxiety disorders among these students.For SAD, the National Institute for Health and Care Excellence (NICE) recommends the use of the Mini-Social Phobia Inventory (Mini-SPIN) (Connor et al., 2001).PTSD was assessed using the 4-item Mini-SPIN which comprise four major questions with a dichotomous 'Yes' or 'No' answer.A score of 'YES' was scored 1 while a score of 'NO' was scored zero.A total score of 2 and above suggests likelihood of having PTSD (The Primary Care PTSD screen, 2016).Panic disorder was assessed with the standardized screening questionnaire which contains 8 major questions with 27 items with a dichotomous answer of 'YES' or 'NO'.An answer of 'YES' was scored 1 while a response of 'NO' was scored zero.A total score of 14 and above suggests panic anxiety disorders (The Primary Care PTSD screen, 2016).Phobia-screening questionnaire was used for specific phobias.It contains 8 items with a dichotomous 'YES' or 'NO' answer.A response of 'YES' was scored 1 while a response of 'NO' was scored zero.A total score of 4 and above suggest phobia (The Primary Care PTSD screen, 2016), OCDs questionnaire contains six items with a dichotomous 'YES' or 'NO' answer.A score of 'YES' was scored 1 while a score of 'NO' was scored zero.A total score of 3 and above suggest phobia (Tabalipa et al., 2018).For GAD, the GAD-scale was used to screen the students (Bibi & Nasir Ali, 2015).The initial item pool consisted of 8 items that reflected all of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV).The questionnaire was developed by asking the study subjects the frequency by which they were bothered by each symptom during the last 2 weeks.Response options were 'not at all', 'several days,' 'more than half the days,' and 'nearly every day': which scored as 0, 1, 2, and 3 respectively.In addition, an item to assess duration of anxiety symptoms was included.A score of 52-100 % indicated anxiety disorder or a score of ≥11 on GAD-7 indicated anxiety (Robert et al., 2006).

Data Analysis
Data were analyzed using the Statistical Package for Social Sciences program (SPSS version 20 Chicago.).Chi-square was used to test significant association for the qualitative variables while multivariate logistic regression was used to determine correlation.A p-value less than 0.05 was taken as significant for each statistical test

Ethical Consideration
Ethical clearance was sought and obtained from the Ethics Committee of the Enugu State University Teaching Hospital, Enugu.

Discussion
In the present study, the overall prevalence of anxiety disorders among medical students was 14.3%.Specifically, the relative frequencies of GAD, PTSD, SAD, panic disorder, specific disorder and OCDs were 39.6%, 32.3%, 17.1%, 5.1%, 33.6% and 18.0% respectively.The overall prevalence of anxiety disorders noted in this study is comparatively lower than the prevalence of 47% reported among medical students with multiple nationalities in Saudi Arabia: comprising Arabs, South Asians, and North Americans (Bibi & Nasir Ali, 2015).Interestingly, the study observed a higher prevalence of 63% among these students prior to examinations which rapidly declined to 47% after the examinations.Elsewhere in Malaysia, Sherina et al (2005) also noted a higher prevalence of 38.4% in their study among Malaysian medical students.Disparities between these prevalence rates may be due to study methodology, sample size, the type of questionnaire used and ethno-geographic variables.Nevertheless, the high prevalence rates of anxiety disorders among medical students underscores the need to possibly review the curriculum, examination methods, study environment and accommodation, which are all potential stressors and triggers of anxiety.
We noted in this study that GAD was significantly associated with gender and year of study.Specifically, there was a female preponderance among medical students in the clinical setting (especially 4 th and 5 th year of study) who exhibited this disorder, which was however least observed among the final year students.Challenges of facing new learning techniques in the clinical class such as clerking of and interacting with patients, as well as exposure to hospital environment to which these students were not hitherto exposed are all contributory factors.For the final year students, expectations to become competent doctors and to acquire good academic results may account for the low prevalence of the disorder among them (Zaid et al., 2007).
It is generally believed that females tend to have more anxiety symptoms than their male counterparts: an assumption which has been corroborated by the finding of the current study.Suggested reasons for this tendency include greater social freedom for expression of feelings, physiologic and neuro-hormonal factors ( (Blanch et al., 2008;Andrade et al., 2006;Soumya et al., 2006).The prevalence rate of 32.4% for PTSD obtained in the current study is less than the rates of 21.9% and 22.9% reported by Shrestha et al (2015), and Ameel et al ( 2011) respectively.Again, differences in study location, the questionnaire used as screening tool for anxiety disorders and sample size may account for this disparity in prevalence rates.Interestingly, PTSD were mainly noticed in the second year of study among medical students evaluated in the current study: a period these students are exposed to cadaveric dissection in learning the subject of Anatomy.A study by Peter & Lawrence (1990) noted that approximately 5% of the students in Anatomy class reported nightmares, intrusive visual images, insomnia, depression, and learning impairments.These psychologic responses strongly resemble PTSD: making the authors to conclude that the Anatomy laboratory may represent a significant emotional challenge to many medical students, as it may represent the student's first intimate experience with illness and death (Peter & Lawrence, 1990).Furthermore, the non-significant association of PTSD with age, marital status, profession, previous disaster experience, tragic events with relatives was also corroborated by Shrestha (2015).
The prevalence rate of 33.6% for SAD reported in this study is lower than the 56% recorded in Malaysia by Gill & Mohammad (2010).Again, SAD and panic disorder appeared significantly related to the year of study.For instance, these disorders were worse among 200 level students compared to other levels of medical training.Importantly, the reason for this observation may be the commencement of exposure of the students at this level of study to morbidity and mortality stereotypes like cadaveric dissection.
The present study also found that medical students who were not married were more likely to have phobia compared to their married counterparts.In addition, students whose parents were low-income earners and students with low monthly allowance all showed more tendency to phobia compared to students whose parents were high-income earners and their counterparts with high monthly allowance.Although Ali (2013) reported no significant difference in the prevalence of social phobia with respect to gender, family income or type of residence, another author in Baghdad, Iraq (Abdul, 2012) noted a significant association of phobia among medical students with rural residence and low socio-economic background.This study shows a high tendency for married students and those from high socio-economic class to have some protection from the component anxiety disorders.
Although the reason remains unclear, it has been documented that married students were significantly less susceptible to anxiety disorders compared to their single-status colleagues while those not involved in a romantic relationship were found to have significantly more anxiety disorders that those who were not (Johari & Hashim, 2009).
The prevalence of 33.6% for specific phobia obtained in this study compares well with the prevalence of 27% among medical students in the study by Ali (2013).Remarkably, it is much higher than the rates among non-medical undergraduate students by reported Johari & Hashim (2009), who documented a life-time and 12-month prevalence of 9.4% and 8.5% respectively.The reason for this high prevalence rate of phobia among medical students when compared to their non-medical counterparts may include fear of examination failure and course-withdrawal associated with medical schools.
Finally, in the present study, OCDs were found to be significantly related to marital status and year of study.These findings are in tandem with the observations of Torres et al (2016), who noted that prevalence rates for this disorder were higher among fresher students (year 1 and 2 students).According to these authors, the 'obsession' dimension was also associated with being a 'freshman' (Torres et al., 2016).

Study Limitations
The study was a single-center evaluation of medical students.Findings may not therefore be representative of these disorders among medical students in Nigeria.Secondly, the standardized questionnaires used as screening tools were self-administered and not interviewer-administered, giving room for possible wrong responses among students who might fully not have comprehended the items.

Conclusion
Medical students in Nigeria are prone to a spectrum of anxiety disorders.This susceptibility is influenced by socio-demographic characteristics.

Table 1 .
Socio-demographic characteristics of respondents

Table 2 .
Associations between factors and anxiety disorder (AGGREGATE)

Table 3 .
Associations between factors and General Anxiety Disorder

Table 4 .
Associations between factors and Post-traumatic stress Disorder

Table 5 .
Associations between factors and Social Panic Anxiety Disorder

Table 6 .
Associations between factors and Panic Anxiety Disorder

Table 7 .
Associations between factors and Specific Phobia

Table 8 .
Associations between factors and Obsessive-compulsive disorder