The mediating role of depression, anxiety, and sleep in the relationship between type D personality and asthma control: a cross-sectional study.

Type D personality, defined by the co-occurrence of negative affectivity and social inhibition, has been associated with poorer health outcomes in chronic diseases, including asthma. However, the psychological mechanisms underlying the relationship between Type D personality and asthma control remain unclear. This cross-sectional study included 150 adult patients with asthma recruited from a tertiary outpatient clinic. Participants completed the Asthma Control Test (ACT), Type D Personality Scale (DS-14), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), and Pittsburgh Sleep Quality Index (PSQI). Type D personality traits were identified in 39.3% of the sample. Compared with non-Type D individuals, patients with Type D personality had higher depressive and anxiety symptom scores and poorer sleep quality (all p < 0.05). Mediation analyses using bootstrapping (5,000 resamples) revealed significant indirect effects of Type D personality on asthma control through depression (β = -0.088, 95% CI [-0.132, -0.047]), anxiety (β = -0.115, 95% CI [-0.158, -0.078]), and sleep quality (β = -0.057, 95% CI [-0.091, -0.029]). These indirect effects remained statistically significant after adjustment for age, sex, smoking status, and FEV1 (% predicted). These findings suggest that Type D personality is indirectly associated with poorer asthma control through increased psychological symptom burden and impaired sleep quality.