Medical student mental health and the role of rumination

Mental illness is the second leading reason for tertiary students in Aotearoa New Zealand to consider dropping out of studies.¹ Twelve percent and 10% of New Zealanders aged 15–24 report moderate or greater symptoms of depression and anxiety, respectively (according to General Anxiety Score-7 [GAD-7] and Patient Health Questionnaire-9 [PHQ-9]), and rates have increased over time.² These symptoms appear to be more prevalent among the New Zealand tertiary student population,³ including medical students.⁴ Globally, meta-analyses report moderate or greater symptoms of depression in 27%⁵ and anxiety in 34%⁶ of medical students; however, these estimates are based on studies that use a range of different measures, making direct comparison with the former studies challenging. What is clear is that medical students face many risk factors contributing to poor mental health, including academic pressure, social isolation due to study location or hours, fear of impact of help-seeking on career progression/fitness to practice, perfectionistic personality traits and mental health stigma in medicine.^7,8

Rumination has been identified as a transdiagnostic risk factor for anxiety and depression symptoms in medical student populations.^9,10 Rumination is characterised by repetitive thoughts focussing on one’s negative emotions, and is categorised into two components: brooding and reflection.¹¹ Brooding has been linked to the development of depressive symptoms over time and maladaptive coping, whereas preliminary evidence suggests reflective rumination is associated with concurrent, but not longitudinal, depressive symptoms and more adaptive coping strategies.^11,12 Although rumination is an important treatment target, no studies in New Zealand thus far have examined rumination alongside mental health symptoms in tertiary students. We conducted a survey to examine the rate of depression and anxiety symptoms, as well as rumination, in a Christchurch-based medical student sample.

Methods

Ethics approval for the survey was granted by the University of Otago Human Ethics Committee (23/044). Survey distribution occurred between 9 June 2023 and 31 August 2023. Survey promotion occurred through email, social media, in-person promotion at large group teaching and word-of-mouth. All participants provided written informed consent.

The online Qualtrics survey collected the following data:

• Demographic details: gender (female, male, other) and ethnicity.
• Depression, anxiety and stress symptoms: the Depression Anxiety Stress Scale 21 (DASS-21) was used to identify mild, moderate, severe and extremely severe levels of depression, anxiety and stress symptoms, based on established cutoffs on the DASS-42.¹³ DASS-21 is widely utilised as a measure of mental health symptoms in international student studies^5,6 and was used in the most recent comparable New Zealand study.⁴
• Rumination: the Ruminative Responses Scale (RRS) included 22 questions on reflection, brooding and depression-related rumination symptoms.

In this paper, data were analysed using SPSS (version 31). Comparisons of mean scores of male and female genders used independent sample t-tests. A one-way ANOVA was used to explore the effect of ethnicity on survey outcomes. Games–Howell testing was used for post hoc comparisons. Pearson correlation analyses were used to investigate associations between rumination and depression and anxiety symptoms.

Results

One hundred out of a possible 335 (29.9%) medical students completed the survey. Seven students did not complete the RRS. Seventy-six students were female, 23 were male and one was non-binary. Respondents included 15 Māori, 57 Pākehā/NZ European, 25 Asian, one Pacific and two Other ethnicities.

Fifty-three percent of students reported above normal depression symptom levels: 17% mild, 16% moderate, 8% severe and 12% extremely severe. Fifty-five percent of students reported above normal anxiety symptom levels: 10% mild, 16% moderate, 13% severe and 16% extremely severe. Fifty-four percent of students reported above normal stress levels: 12% mild, 21% moderate, 15% severe and 6% extremely severe.

View Table 1–3, Figure 1.

Mean DASS and RRS subscale scores for the total sample, as well as by gender and ethnicity, are presented in Appendix Table 1.

The mean DASS anxiety score was significantly higher in female students than male students (mean difference=4.37, t=2.27, p<0.05). Although female mean scores were higher in every other measure, the differences were not statistically significant.

Survey findings by ethnicity are displayed in Figure 1. One-way ANOVA, comparing Pākehā, Māori and Asian groups, found significant between-group differences across all RRS subscales (p<0.02). Post hoc analysis revealed that Asian students had significantly higher mean scores than Pākehā students in RRS brooding (F=4.80, p=0.03) and RRS total (F=5.06, p=0.04).

Exploratory analysis revealed significant, positive correlations among all DASS and RRS subscales, including their total scores (see Table 3).

Discussion

This survey shows concerningly high levels of depression, anxiety and stress symptoms in medical students, with clear links to rumination. A substantial proportion of this Christchurch-based medical student cohort had moderate or greater levels of depression symptoms (36%), anxiety symptoms (45%) and stress (42%). Female students reported significantly more symptoms of anxiety than male students. Asian students reported significantly higher levels of brooding and total rumination than Pākehā students. While not statistically significant, Māori students reported higher levels of depression and anxiety symptoms, stress and rumination than Pākehā students. This is in keeping with the higher prevalence of mental illness symptoms reported in Māori adults compared to all other ethnicities in the New Zealand Health Survey.² These findings likely reflect broader social and structural determinants of mental health. Further research is required to explore the experience of Māori medical students, ideally within a larger sample size for increased power.

This sample reported greater levels of depression and anxiety symptoms than the Tōku Oranga study, which found moderate or greater symptom levels of 32% depression and 34% anxiety using the DASS-21 on a Christchurch-based medical student sample in 2019–2020.⁴ Compared with this study, the Tōku Oranga study has very similar demographics and response rate (28%). The increase in depression and anxiety symptoms in a similar cohort may be partly explained by lasting effects of the COVID-19 pandemic, or may simply reflect worsening mental health in the broader population as reported in the 2024 New Zealand Health Survey.²

This is the first study to examine rumination in New Zealand medical students. We found strong positive correlations between rumination, particularly the brooding component, and depression, anxiety and stress symptoms in our study cohort. This is consistent with existing research, highlighting rumination as a transdiagnostic risk factor and potential treatment target.^9,10 We are now, therefore, developing and testing brief interventions targeting rumination, with the potential for use across New Zealand tertiary student samples in treating and preventing depression and anxiety disorders (trial registration number: ACTRN12624000758505p).

This study has several limitations. Response bias is likely, with a response rate of 30%. Male students were under-represented at 23%. Self-selection may have attracted individuals with experience of mental illness, while excluding individuals with mental illness severe enough to prevent participation. DASS-21 and RRS are self-reported symptom questionnaires, not formal diagnostic measures. Finally, the cross-sectional study design prevents any understanding of causality.

Medical student mental health in New Zealand is a major concern. The medical profession ultimately relies on the wellbeing of its future practitioners, underscoring the need for focussed attention in this area. Although systemic and institutional approaches are needed to address the stressors students face, rumination is likely an important contributor to negative mental health outcomes. Further research is required to tailor accessible interventions for students with high levels of rumination.

View Appendix.