Two-thirds of patients with seasonal affective disorder (SAD) improve with light therapy, often starting within one week. Most find the 15- to 30-minute regimen easy to fit into daily life, and with the recent introduction of light boxes costing about $100, regard treatment as affordable.

Despite demonstration of light therapy's benefits over the past 25 years, many psychiatrists have yet to incorporate it into their practice, Raymond Lam, M.D., a professor of psychiatry at the University of British Columbia in Vancouver, told PsychiatricNews.

Aiming to change that, he and Edwin Tam, M.D., a clinical associate professor of psychiatry at the University of British Columbia, developed A Clinician's Guide to Using Light Therapy (Cambridge University Press, 2009).

Lam and Tam describe clinical features and differential diagnosis of SAD and discuss who should and should not use light therapy. They offer advice on selecting light devices, monitoring clinical response, managing side effects, and combining light therapy with antidepressants and other treatments. They also provide clinician resources, including patient questionnaires, instruction sheets, rating scales, and a sample insurance reimbursement letter.

In addition, they discuss light treatment for nonseasonal depression and other psychiatric disorders.