Sleep disturbance as a potential mediator for stress frequency and internalizing psychopathology

Stress predicts sleep disturbance and is a risk factor for internalizing psychopathology (anxiety and depression). Sleep disturbance can also be a risk factor for these disorders, suggesting it may mediate links between stress and internalizing psychopathology, but previous literature has not directly tested this model. I hypothesized that sleep disturbance would mediate stress frequency predicting internalizing psychopathology and investigated whether these links were specific to anxiety or depression, or common to both. In the current study, 603 treatment-seeking undergraduate and graduate students completed stressful life event, sleep disturbance, anxiety symptom, and depression symptom questionnaires during their first session at the Brandeis Counseling Center. The hypotheses were tested with two mediation models, one with anxiety and depression symptoms separately, and one with an internalizing psychopathology composite as outcomes. Because sleep disturbance and stress may be outcomes as well as risk factors of internalizing psychopathology, we compared the fit of the hypothesized models to reversed models. Sleep disturbance mediated the association between stress and general internalizing, depression, and anxiety symptoms, with no significant differences between depression and anxiety effects. For the reversed models, sleep disturbance mediated the association between anxiety and depression, and stress, with anxiety having a larger significant association on sleep disturbance. These findings demonstrate the importance of sleep maintenance to prevent stress and internalizing psychopathology, specifically in vulnerable populations, such as college students.