In most cases, seasonal affective disorder symptoms appear during late fall or early winter and go away during the sunnier days of spring and summer. Less commonly, people with the opposite pattern have symptoms that begin in spring or summer. In either case, symptoms may start out mild and become more severe as the season progresses. Signs and symptoms of SAD may include: SAD 
Feeling listless, sad or down most of the day, nearly every day
Losing interest in activities you once enjoyed
Having low energy and feeling sluggish
Having problems with sleeping too much
Experiencing carbohydrate cravings, overeating and weight gain
Having difficulty concentrating
Feeling hopeless, worthless or guilty
Having thoughts of not wanting to live
 Fall and winter SAD Symptoms specific to winter-onset SAD, sometimes called winter depression, may include: SAD 
Oversleeping
Appetite changes, especially a craving for foods high in carbohydrates
Weight gain
Tiredness or low energy
 Spring and summer SAD Symptoms specific to summer-onset seasonal affective disorder, sometimes called summer depression, may include: 
Trouble sleeping (insomnia)
Poor appetite
Weight loss
Agitation or anxiety
Increased irritability
 Seasonal changes and bipolar disorder People who have bipolar disorder are at increased risk of seasonal affective disorder. In some people with bipolar disorder, episodes of mania may be linked to a specific season. For example, spring and summer can bring on symptoms of mania or a less intense form of mania (hypomania), anxiety, agitation and irritability. They may also experience depression during the fall and winter months.