[Phototherapy: clinical and therapeutic evaluation of a 2-year experience]

The concept of seasonal periodicity in psychiatry has been studied for thirty years in different domains, particularly in that affective disorders. It seems to be established that winter seasonal depressions are correlated to a particular vulnerability to the decrease in ambient light; this led directly to the development of phototherapy as primary treatment of SAD, simultaneously to the development of the clinical concept. Since the first demonstration by Rosenthal of the efficacy of phototherapy in SAD, numerous studies have confirmed that bright light provides rapid and effective treatment for this type of disorder. Phototherapy has been used at the Centre Psychothérapique des Hôpitaux Civils de Colmar for five years in three ways: as an alternative treatment to medication, in addition to antidepressive medication, and as primary treatment of seasonal depression. We describe the evaluation protocol of this treatment, which was established in collaboration with the Psychiatric Clinic of the University of Basel. The principal inclusion criterion for this study was the presence or regular phases of depression or loss of energy in autumn and winter; the regularity of the appearance of symptoms in winter was predominant over the severity of the symptoms, their seasonal occurrence being the most important predictive factor in favour of phototherapy. Our prospective study enabled us to include, over a period of two years, 18 subjects presenting very different symptomatology. Though the sample was heterogeneous, the results of treatment efficacy are satisfactory: we note effectively a decrease of 67.5% in the modified Hamilton scale even though strict criteria for seasonality (Seasonal Screening Questionary, Rosenthal's Criteria) were not always respected. These data should lead us to widen the indication for phototherapy, particularly in patients presenting mood disorders which are not exclusively seasonal, and support the accumulating experimental data for the selective antidepressive effect of light.