For a comprehensive overview of all types of mental illness, visit Psych Central. Launched in 1995, the site is one of the longest-running mental health outposts online, and it was named one of Time.com's 50 Best Websites in 2008. You will find places to network with peers, a medication library and quizzes, such as “Do I need therapy?”

Mental Help Net is nearly as old and also award-winning. The amount of information here is staggering, but do not miss “Depression: A Primer” by a blogger and illustrator named “Ellen” who has struggled with the disease. To hear from other patients in their own words, go to Schizophrenia.com. In addition to a collection of blogs by people who have schizophrenia, it offers a comprehensive guide to living with the illness.

Millions of people endure anxiety, eating disorders and obsessive-compulsive disorder—but few realize that these ailments are all related. At the oddly named but excellent site called BrainPhysics, sufferers can explore the roots of these obsessive-compulsive spectrum disorders, find local doctors and support groups, and chat with others who have gone through similar experiences.

The Internet seems to be saturated with information for parents about attention-deficit hyperactivity disorder (ADHD) and other learning disorders, but few sites offer something for the kids themselves. At LD Online, a section for kids featuring a child artist and writer every day complements an exemplary collection of knowledge for parents.

Perhaps the most promising new addition to the online mental health scene is afterdeployment.org, a site for veterans and active servicemen and servicewomen who may be dealing with a host of problems, including post-traumatic stress disorder, anxiety and depression. The Department of Defense, along with an impressive lineup of psychiatrists and psychologists, created the site because of a congressional mandate. Launched in August, the sleek, interactive portal offers videos, self-check quizzes and online workshops, but one of its most important features is that it allows its users to remain anonymous. Many service members fear the stigmatization that therapy may bring in the culture of the armed forces—this site has the potential to help those people with its perfect use of the impersonal yet intimate nature of the Internet.

PsychCentral: http://psychcentral.com

Mental Help Net: www.mentalhelp.net

Schizophrenia.com: www.schizophrenia.com

BrainPhysics: www.brainphysics.com

LD Online: www.ldonline.org

afterdeployment: www.afterdeployment.org