The ideal is an angle of about 30° to 60° to let enough light meet the eye and allow for the patient to, for example, read or eat during light therapy. The intensity of light critically depends upon the distance from the light source. Light boxes should be powerful enough to deliver an intensity of about 10 000 lux at a distance of 60 to 90 cm. If the light box is less powerful, treatment

time should be expanded (see above). Patients Inhibitors,research,lifescience,medical should be encouraged to seek exposure to environmental light on sunny days. Sunlight has much higher intensity than light delivered by a light therapy device (see above). Despite the fact that light therapy is now recommended as a treatment of choice for SAD, only in Switzerland has the economic argument that in the long run, light

is cheaper than drugs, attained government endorsement and mandatory reimbursement by medical insurance.51 Inhibitors,research,lifescience,medical The fact that there is no reimbursement for light therapy has been widely criticized by patients with SAD, their relatives, and experts in the field of SAD.52 Case reports on SAD patients resistant to several antidepressants, but finally responsive to light therapy illustrate that, although depressive symptoms may often be only moderate, SAD can lead to severe impairment in occupational and social functioning and can precipitate catastrophic life events.52,53 Pharmacotherapy Although light therapy is recommended as Inhibitors,research,lifescience,medical the first-line option for SAD, some patients do not experience sufficient relief of depressive symptoms with light. BLT can then be supplemented with antidepressant Inhibitors,research,lifescience,medical drugs. Other patients with SAD feel unable to integrate light therapy into their daily routine, or other logistical difficulties in administering light therapy are present. The evidence of SAD being Inhibitors,research,lifescience,medical associated with a dysfunction in brain serotonin systems has guided the search for promising pharmacological treatments of SAD. Data emerging from multiccntcr placebo-controlled trials has led to the recommendation of the SSRIs sertraline and fluoxetine as first-line treatments of SAD. Other antidepressant compounds, like monoamine oxidase inhibitors, dopaminergic

and noradrenergic agents, melatonin, β-blockers as melatonin antagonists, herbs, and nutritional supplements like L-tryptophan and vitamin D have been investigated in small studies. The efficacy Fossariinae of these medications has not yet been proven in SAD. Open trials, controlled studies, and placebo-controlled studies in SAD are EGFR inhibitor listed in Tables III to V.54-75 New pharmacological agents are of potential value in the treatment of SAD, for example, agomelatine (Valdoxan).This new dual melatoncrgic and specific serotonergic antidepressant has been shown to be efficient in the treatment of major depression76: it exhibits a specific core action on circadian rhythms, and therefore could be of particular value in the treatment of SAD. More specific studies are underway to more obtain information about its activity in SAD.