Stress and delusions in postgraduate medical students: the mediating role of anxiety and depression and the moderating role of trait impulsivity

Postgraduate medical students face tremendous stress from multiple sources, which not only affects their professional performance, but may also have a wide and deep impact on their mental health through the intervention of affective states like depression and anxiety, and modulating factors such as personal impulsivity. Notably, this complex process of influence may increase the likelihood of certain psycho-pathological symptoms (e.g. delusions). However, this complex network of relationships and its specific mechanisms of action still require more field studies to validate and elucidate. This study explored the correlations of stress, anxiety, depression, impulsivity, and psychosis symptoms (delusions), while also examining the moderating role of impulsivity within this model. 6934 graduate students (2799 males and 4135 females) at a medical school were enrolled in the study, and asked to complete 10-item Perceived Stress Scale, Delusion symptoms scale, Anxiety Disorder Questionnaire, Patient Health Questionnaire-9 and Brief Barratt Impulsiveness Scale. Results indicated stress significantly and positively predicted delusions, with anxiety and depression mediating the stress-delusion relationship. In addition, Impulsivity moderated the effects of stress on anxiety, stress on depression, and stress on delusions. For individuals with high impulsivity, the impact of stress on anxiety and depression was more significant, indirectly increasing the risk of delusions. In contrast, for individuals with low impulsivity, the negative effects of stress on delusions were relatively small. Our study highlighted that postgraduate medical students experiencing high academic and life stress were more susceptible to anxiety and depression, increasing the risk of delusions. Therefore, targeted mental health interventions are essential for this group, emphasizing stress management, emotion regulation, and impulse control.