Publisher's Synopsis
Discourse about the relationship between seasons and human mood has a substantial history in medicine, the arts and the social sciences . Over the last decade, this perennial topic has been dominated by the construct of Seasonal Affective Disorder (SAD). SAD is a psychiatric syndrome characterised by depressions which recur at the same time each year, typically winter (Rosenthal et al, 1984b). SAD is typically understood as the extreme end of a continuum of normative seasonal variation in mood and behaviour (seasonality). The research reported here had four interrelated aims. The first aim was to test for the existence of seasonality in human mood (as defined by SAD). It can be argued that this topic is both important and potentially fruitful. Seasonality is critical for the validation of SAD itself: it has been proposed that the most important unresolved issue of SAD research is the definition of seasonality. Furthermore, seasonality is a scientifically interesting construct, because it implies a unique trait of mood variability in the context of environmental changes. As such, the investigation of seasonality provides a test of current understandings of the relationship between personality, mood and affective vulnerability. The second aim of the research, therefore, was to situate seasonality in the nomological web of trait constructs. The third aim was to test a novel hypothesis about the psychobiology of the trait of Neuroticism, a hypothesis that derived from the integration of seasonality into the nomological net of personality constructs. The key dependent variable in the research was mood, and therefore a fourth aim was to investigate a contemporary model of mood by testing the hypothesis that a Positive Affect system is partially driven by biological rhythms.
