From social withdrawal sub-types to sleep problems: the cross-sectional and longitudinal mediating role of depression.

The approach-avoidance motivation theory divides social withdrawal into three sub-types: Social avoidance, shyness, and unsociable. Behavioral patterns influence physiological health according to the mind-body medicine model. Previous studies had associated withdrawal sub-types with depression, and sleep problems are typical symptoms of depression. Therefore, it was reasonable to hypothesize that withdrawal sub-types predict sleep problems through depression. However, the association between withdrawal and sleep problems, and the possible mediating role of depression between them, was rarely explored. Thus, the present research (targeted Chinese college students) aimed to study the relationships of withdrawal sub-types, depression, and sleep problems, comprised comprising two questionnaire-survey studies: Study 1 (N = 494) explored the cross-sectional relationships with hierarchical multiple regression and cross-sectional mediating analysis. Study 2 (N = 233) examined the longitudinal relationships with three-wave longitudinal mediation models. The results of study 1 showed that both social avoidance and shyness significantly predicted sleep problems fully through depression, but unsociable was not associated with depression or sleep problems. The results of study 2 showed that social avoidance was the only sub-type longitudinally predicted sleep problems through depression. The conclusion was that social avoidance is may be the riskiest sub-type due to its significant associations with the two outcomes in both studies, the effects of shyness on the two outcomes are questionable due to its conflicted results of two studies, unsociable is may be the most benign sub-type due to its weak associations with the two outcomes. The different relationship-patterns of three sub-types implicate that socially avoidant college students are potentially at higher risk of depression and sleep problems and require special attention.