IMAGES PROVIDED BY:
(1) Science Source / Photo Researchers, Inc.
(2) Glowimages
(3) Bartomeu Amengual / age fotostock
(4) Jutta Klee / Stone
(5) Symphonie / Iconica
(6) Nikolaevich / Photonica
(7) Jetta Productions, Inc / Iconica
(8) 3D4Medical.com
(9) Megan Wyeth / Aurora
(10) Charles Gullung / Photonica
(11) Image Source
(12) Steve McAlister / Riser
(13) Mauro Fermariello / Photo Researchers, Inc.
(14) Mauro Fermariello / Photo Researchers, Inc.
(15) Katzer / Mauritius
(16) Christopher Furlong / Getty Images
(17) Dr. Jeremy Burgess / Photo Researchers, Inc.
(18) Leigh Schindler / Photodisc
(19) Alistair Berg / Digital Vision
(20) David J. Phillip / AP
(21) Will McIntyre / Photo Researchers, Inc.
(22) Universal Images Group / Getty
(23) Frank Gaglione / Riser
SOURCES:
Barkham, M. British Medical Bulletin, 2001.
Gjerdinjen, D. Journal of the American Board of Family Medicine, 2007.
Harvard Health Publications: "Exercise and Depression."
Johns Hopkins Health Alerts: "The Many Benefits of Pets."
Johns Hopkins Medicine: "Seasonal Affective Disorder."
Mental Health America: "Co-occuring Disorders and Depression."
National Institute of Mental Health, National Institutes of Health: "How is depression diagnosed and treated?" "What causes depression?" "What are the signs and symptoms of depression?" "What illnesses often co-exist with depression?" "Magnetic Stimulation Scores Modest Success as Antidepressant," "Major Depressive Disorder in Children."
The Merck Manual: "Depression."