Disturbo Affettivo Stagionale e Sindrome Premestruale

Objective: It has been accepted, since ancient times that seasonal environmental changes affect human behaviour and mood. Modern psychiatric research has proved the existence of pathological chronobiological factors. One of the main features in such disorders is the cyclical pattern, such as the well-known Seasonal Affective Disorder (SAD) first described by Rosenthal in the 80's. Of the cyclical disorders, the Premenstrual Syndrome (PMS) shows clinical analogies compared with Seasonal Affective Disorder. Aim of the study is to: a. evaluate the prevalence either of the Seasonal Affective Disorder and of the Premenstrual Syndrome in a sample of women unaffected by psychiatric disturbances, and b. evaluate the statistical prevalence of the Premenstrual Syndrome in a sub-group of women with a diagnosis of Seasonal Affective Disorder and the probability of association between the two disturbances, if any. Methods: A sample of 511 women in reproductive age and living in Central Italy (latitude of 41°-44°N) were studied. The subjects filled in an Italian adapted version of the Seasonal Pattern Assessment Questionnaire (SPAQ). Added to the questionnaire was a section to investigate the mood and tendency in changing behaviour during the ovulatory cycle. To discriminate the subjects affected by SAD, Subsyndromal-SAD, Summer-SAD, PMS and healthy subjects, a SPAQ scores methodology was adopted, in accordance with "Kenes criteria". The prevalence of SAD, Subsyndromal-SAD and PMS were calculated using the descriptive statistical tool. The statistical relation between SAD and PMS was analysed using the Prevalence Odds Ratio. Results: In the sample, the prevalence of SAD is 4.1%, Subsyndromal-SAD 13.9%, Summer-SAD 1.6% (Chart 2). The prevalence of PMS in the whole sample is 20.7% (Chart 2). The prevalence of PMS in the sub-sample of women affected by SAD is 42.9%, while in the sub-sample of women affected by Subsyndromal-SAD the prevalence is 32.4% (Chart 3). The Prevalence Odds Ratio for PMS and SAD is 3.03 (95% CI = 1.24-7.41); the Prevalence Odds Ratio for PMS and Subsyndromal-SAD/SAD is 2.48 (95% CI = 1.512-4.088). Conclusions: The prevalence of the Seasonal Affective Disorder emerging from the study results is comparable to that of similar studies performed in areas at Central Italy latitudes. Likewise, the results related to the prevalence of PMS are not unlike those from similar studies. Thus, the Premenstrual Syndrome and Seasonal Affective Disorder seem to be widespread in the female population of Central Italy. In addition, at a glance, it is reasonable to hypothesize that Seasonal Affective Disorder and Premenstrual Syndrome are disturbances with a high grade of overlapping as far as concents epidemiology. Furthermore, the prevalence Odds Ratio value > 1 confirms the hypothesis of the vulnerability to the premenstrual mood and behavioural variations in women affected by Seasonal Affective Disorder.