High prevalence of seasonal affective disorder among persons with severe visual impairment

BackgroundLight severely affects the occurrence of seasonal affective disorder (SAD).AimsTo compare the prevalence of SAD in persons with severe visual impairment and persons with full sight, and in persons with severe visual impairment with or without light perception.MethodThis cross-sectional study assessed the Global Seasonality Score (GSS) and the prevalence of SAD among 2781 persons with visual impairment and 4099 persons with full sight using the Seasonal Pattern Assessment Questionnaire (SPAQ).ResultsRespondents with visual impairment had significantly higher GSS and prevalence of SAD compared with full sight controls, P<0.001. Light perception respondents were more vulnerable to seasonal change than both full sight and no light perception respondents.ConclusionsThe study showed a highly significant association between visual impairment and SPAQ-defined SAD parameters, supporting the hypothesis that decreased retinal light input plays a role in the pathogenesis of SAD.