Depression severity and psychosocial determinants of physical activity behavior in in-patients with major depressive disorders

Background: Physical inactivity is a world-wide health issue. In people with major depressive disorders
approximately 68% do not reach the recommended physical activity levels. Psychosocial determinants of and
implicit attitudes towards physical activity serve to explain physical activity behavior and may form the basis of
interventions to promote physical activity. The aim of this study was to examine, whether psychosocial de-
terminants and implicit attitudes towards physical activity vary according to depression severity.
Methods: Physically inactive, adult in-patients diagnosed with major depressive disorder (according to ICD-10)
were recruited from four Swiss psychiatric clinics. Psychosocial determinants of physical activity were
assessed with seven questionnaires pertaining to motivational and volitional aspects of physical activity. Implicit
attitudes towards physical activity were measured with a computer-based Single Target Implicit Association Test.
Results: In-patients (N = 215, Mage = 41 ± 13 years, 53% female) with major depressive disorder reporting more
severe (n = 52) depression symptomology exhibited less favorable psychosocial determinants for physical ac-
tivity behavior (self-efficacy, negative outcome expectancies, intention, intrinsic motivation, introjected moti-
vation, external motivation, action planning, perceived barriers, coping planning) compared to those with mild
(n = 89) and moderate (n = 74) depression symptomology. Positive outcome expectancies, identified, social
support and implicit attitudes towards physical activity did not vary according to depression severity.
Conclusions: Psychosocial determinants of physical activity do vary according to depression severity. Attempts to
promote physical activity among people with major depressive disorder should take depression severity into
account when developing and delivering interventions