SEASONAL AFFECTIVE-DISORDER - A GUIDE TO DIAGNOSIS AND MANAGEMENT

Seasonal affective disorder (SAD) is characterised by recurrent depres sive episodes, occurring typically in winter(i.e. winter SAD). The aty pical symptoms of depression frequently precede the onset of each epis ode and are closely associated with the recurrence of the episodes. Wi nter depressive episodes are mostly of mild to moderate severity. Pati ents with winter SAD seldom require hospitalisation, have psychotic sy mptoms or are at risk of suicide. However, most patients do experience marked impairment of functioning at work and in their social relation s. Light therapy is the treatment of choice fur patients with winter S AD. Treatment with bright light in the morning results in remission in two-thirds of patients with mild episodes, but in le:ss than half of those with moderate to severe episodes. The clinical response to the d aily administration of light is usually observed within 1 to 2 weeks o f the onset of this treatment. The presence of atypical symptoms of de pression, rather than the severity of the episode, best predict a ther apeutic response to light therapy. It is recommended that therapy be c ontinued throughout the winter to prevent relapse and optimise outcome . Preliminary data from controlled trials indicate that drug treatment may also be effective in patients with winter SAD. Current data sugge st efficacy for the selective serotonin (5-hydroxytryptamine; 5-HT) re uptake inhibitors fluoxetine anti sertraline. and the reversible inhib itor of monoamine oxidase A moclobemide. There are no studies on the e fficacy of psychological therapies in these patients. Comorbid disorde rs frequently influence the clinical picture in patients uc SAD by mod ulating the course of illness, and each may require specific intervent ion.