(1) Authoritative online information
(2) Recommended books
(3) Authoritative online information about light therapy
(4) Resources for professionals
(1) Authoritative online information
Norman Rosenthal, MD - What is Seasonal Affective Disorder?
Mayo Clinic - Seasonal Affective Disorder
Seasonal Affective Disorder Association (UK)
Portland Psychotherapy Clinic - Winter blues and seasonal affective disorder
A.D.A.M. Medical Encyclopedia (via PubMed) - Seasonal Affective Disorder
Mental Health America - Seasonal Affective Disorder
NHS (UK) - Seasonal Affective Disorder
Consumer Reports - Shedding light on winter depression (2005)
(2) Recommended books
*Note: My top recommendation is Rosenthal's 2013 workbook (see below).
Rohan, K. (2008). Coping with the Seasons: A Cognitive Behavioral Approach to Seasonal Affective Disorder, Workbook. Oxford University Press. [Amazon]
Rosenthal, N. E. (2012). Winter blues - Everything you need to know to beat Seasonal Affective Disorder, 4th Ed. Guilford. [Available at the Corvallis-Benton County Library] [Author's website] [Amazon]
Rosenthal, N. E. (2013). Winter Blues Survival Guide: A Workbook for Overcoming SAD. Guilford. [Amazon]
(3) Authoritative online information about light therapy
(4) Resources for professionals
Rohan, K. J., Meyerhoff, J., Ho, S., Evans, M., Postolache, T. T., & Vacek, P. M. (2016). Outcomes one and two winters following cognitive-behavioral therapy or light therapy for seasonal affective disorder. American Journal of Psychiatry, 173, 244-251. [link]
Seasonal Pattern Assessment Questionnaire (SPAQ) [PDF]