Insomnia and Neuroticism in Pakistani Medical Students: A Cross-Sectional Study

Background: Sleep disorders, particularly insomnia, represent a significant health concern in medical education. Neuroticism, characterized by emotional instability and stress reactivity, shows cross-sectional associations with sleep disturbances in healthcare trainees. Limited research examines these relationships among South Asian medical students. This cross-sectional study investigated insomnia symptom prevalence, personality correlates, and environmental factors among Pakistani medical students. Methods: We conducted a cross-sectional study among 364 undergraduate medical and dental students in Peshawar, Pakistan (June–November 2024). Data collection occurred during examination months. Data collection employed validated instruments: the Insomnia Severity Index (ISI) and the NEO Five-Factor Inventory neuroticism subscale (NEO-FFI-12). Statistical analyses included Pearson correlations, chi-square tests, and multivariate regression with interaction terms. Results: Among 364 participants (mean age 21.3 ± 2.3 years, 52.2% female), 47.0% reported severe insomnia symptoms (ISI 22–28), with 89.0% experiencing at least subthreshold symptoms (ISI ≥ 8) during the 2-week assessment period. These prevalence rates reflect symptom severity over a 2-week period during examination months and do not represent clinical diagnoses of chronic insomnia disorder, which requires ≥3 months of symptoms with clinical confirmation. High neuroticism (NEO-FFI ≥ 37) characterized 59.8% of students. Multivariate regression revealed a robust cross-sectional association between neuroticism and insomnia symptom severity (β = 0.239, 95% CI [0.173, 0.305], standardized β = 0.342, p < 0.001) and may reflect measurement during peak examination stress rather than stable trait-outcome relationships. Hostel residents showed non-significantly higher clinical insomnia prevalence than day scholars (75.9% vs. 67.5%, p = 0.081). Clinical-year students demonstrated significantly lower insomnia severity than pre-clinical students (β = −1.271, p < 0.001), a finding that contradicts assumptions about increasing stress through training progression. The neuroticism × living arrangement interaction was non-significant (p = 0.118); however, post hoc power analysis indicated the study was underpowered to detect small moderation effects, making this finding inconclusive. Conclusions: This study documents high insomnia symptom severity during a 2-week assessment period in Pakistani medical students, with a robust cross-sectional association with neuroticism. However, these findings must be interpreted within the constraints of the cross-sectional design, which cannot establish temporal precedence or causality between neuroticism and insomnia symptoms. These symptom prevalence rates likely reflect a combination of chronic sleep disorders and transient examination-related stress. Living arrangements showed small, non-significant associations with insomnia. The observed association between neuroticism and insomnia may be partially mediated or confounded by unmeasured variables, including academic stress, psychiatric comorbidities, substance use, and other sleep disorders. Findings suggest potential benefits from interventions addressing cognitive-emotional factors, though comprehensive diagnostic assessment is needed to distinguish chronic insomnia disorder from transient, stress-related sleep difficulties. Longitudinal research with objective sleep measures, structured psychiatric assessment, and systematic confounder evaluation is essential to establish causal relationships and intervention efficacy in this population.