Personality factors in Seasonal Affective Disorder: Is seasonality an aspect of neuroticism?

Seasonal Affective Disorder (SAD) is a recently-defined variant of recurrent major depression which is understood as having a uniquely biological aetiology. Notwithstanding the appealing simplicity of lightʹs putative role in the aetiology and treatment of SAD, there are a priori grounds for expecting that a wider range of variables might be relevant. Based on the accepted description of SAD as a continuum of mood vulnerability and the clinical overlap between SAD and neurotic depression, it was hypothesized that the trait construct of neuroticism might prove relevant to SAD. Results suggested that the tendency to report seasonal variation in SAD symptoms covaries with neuroticism. Furthermore, reports of seasonality were found to covary with a tendency to attribute moods to non-seasonal environmental factors beyond the individualʹs control.