A dual vulnerability hypothesis for seasonal depression is supported by the seasonal pattern assessment questionnaire in relation to the temperament and character inventory of personality in a general population.

BACKGROUND: Personality structure obtained from the psychobiological Temperament and Character Inventory (TCI) was studied in relation to self-reported seasonal variations in mood and behavior measured by the Seasonal Pattern Assessment Questionnaire (SPAQ). METHODS: The subjects comprised 1761 adults (57.6% women) in the age range 35-85 years, enrolled in the Betula prospective random cohort study of Umea, Sweden. RESULTS: Personality profiles of subjects who reported the occurrence of a high degree of seasonal variation as such were associated with a combination of high self-transcendence (ST) and high persistence (PS), irrespective of the level of harm avoidance (HA). Subjects who reported feeling worst in winter were associated with high HA, irrespective of the levels of ST and PS. Also, subjects feeling worst in summer or experiencing overall problems with seasonal variation were associated with high HA in their personality profiles. Using the SPAQ criteria to define seasonal affective disorder (SAD) or subsyndromal SAD (S-SAD), subjects with these disorders often had combinations of high self-transcendence (ST) and high persistence (PS), but with different associations with HA. LIMITATIONS: No evaluations were made for SAD or subsyndromal SAD according to the DSM-IV or ICD 10 criteria. CONCLUSIONS: Our results relating SPAQ with TCI give support for a dual vulnerability hypothesis for seasonal depression proposed in the literature, where it is attributed to a combination of a seasonal factor and a depression factor. Examining the literature regarding the relationships between the different TCI scales and monoamine neurotransmitter functions, those relationships suggest that these two vulnerability factors for seasonal depression may be modulated by different neurotransmitter systems.

An epidemiological study on gender differences in self-reported seasonal changes in mood and behaviour in a general population of northern Sweden.

Gender differences have been reported regarding symptoms, prevalence and heritability of seasonal affective disorders (SAD). We focus on gender aspects in this study of self-reported seasonal changes in mood and behaviour in a general population. The Seasonal Pattern Assessment Questionnaire (SPAQ) was completed by 2620 adults (55.6% women) aged 35-85 years, enrolled in the Betula prospective random cohort study of Umeå, Sweden. October to February turned out to be suitable winter months. SAD was found in 2.2% and sub-syndromal SAD (S-SAD) in 5.7%. Women had about 1.5 times higher prevalences than men, and seasonality problems decreased with age in both genders. Preference for eating least was distributed with a peak in summer, whereas preference for eating most had a major peak in winter (winter eaters) and a minor peak in summer (summer eaters). Significantly more of winter eaters in women, and significantly more of summer eaters in men, felt worst in winter. Seasonal change in weight was considered significantly as a problem by women but not by men. Winter behaviour of sleeping most was considered significantly as a problem by men but not by women. Women reacted significantly to temperature-related changes (negatively to cold/short days and positively to hot/long days), whereas men reacted significantly to sunshine-related changes (negatively to cloudy days and positively to sunny days). Subtle gender differences may thus underlie the pathophysiology of seasonal problems. Studies of an eventual efficacy of treating SAD women with raised ambient temperature, and gender-specific comparisons with other therapies, would be of interest.