The meaning of sad is affected with or expressive of grief or unhappiness : How to use sad in a sentence. Major depressive disorder with a seasonal pattern (formerly known as seasonal affective disorder, or sad) is characterized by recurrent episodes of depression in late fall and winter, alternating with Ò€¦

If something looks sad, it looks worse than it should because it is notÒ€¦. Learn more. Bright light therapy is a common treatment for seasonal affective disorder and for circadian rhythm sleep disorders. Information about seasonal affective disorder (sad), a type of depression, including signs and symptoms, how sad is diagnosed, causes, and treatment options.