Seasonal affective disorder (SAD), also known as winter depression, winter blues, summer depression or summer blues, is a mood disorder with which people who have normal mental health throughout most of the year experience depressive symptoms in the winter or summer, spring or autumn, repeatedly, year after year. In the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), SAD is not a unique mood disorder, but is "a specifier of major depression".
Once regarded skeptically by the experts,[who?] seasonal affective disorder is now well established. Epidemiological studies estimate that its prevalence in the adult population of the US ranges from 1.4 percent (Florida) to 9.7 percent (New Hampshire).
The US National Library of Medicine notes that "some people experience a serious mood change when the seasons change. They may sleep too much, have little energy, and may also feel depressed. Though symptoms can be severe, they usually clear up." The condition in the summer is often referred to as reverse seasonal affective disorder, and can also include heightened anxiety.
SAD was first formally described and named in 1984 by Norman E. Rosenthal and colleagues at the National Institute of Mental Health.
There are many different treatments for classic (winter-based) seasonal affective disorder, including light therapy with sunlight or bright lights, antidepressant medication, cognitive-behavioral therapy, ionized-air administration, and carefully timed supplementation of the hormone melatonin.
SymptomsSymptoms of SAD may consist of difficulty waking up in the morning, morning sickness, tendency to oversleep as well as to over eat, and especially a craving for carbohydrates, which leads to weight gain. Other symptoms include a lack of energy, difficulty concentrating on completing tasks, and withdrawal from friends, family, and social activities. All of this leads to the depression, pessimistic feelings of hopelessness, and lack of pleasure which characterize a person suffering from this disorder.
People who experience summer SAD (spring and summer depression) show symptoms of classic depression including insomnia, anxiety, irritability, decreased appetite, weight loss, social withdrawal, an increased sex drive, and suicide. Additionally, many patients are unable to cope with the increased temperatures during spring and summer.
Diagnostic criteriaAccording to the American Psychiatric Association DSM-IV criteria, Seasonal Affective Disorder is not regarded as a separate disorder. It is called a "course specifier" and may be applied as an added description to the pattern of major depressive episodes in patients with major depressive disorder or patients with bipolar disorder.
The "Seasonal Pattern Specifier" must meet four criteria: depressive episodes at a particular time of the year; remissions or mania/hypomania at a characteristic time of year; these patterns must have lasted two years with no nonseasonal major depressive episodes during that same period; and these seasonal depressive episodes outnumber other depressive episodes throughout the patient's lifetime. The Mayo Clinic describes three types of SAD, each with its own set of symptoms.
In the popular culture, sometimes the term "seasonal affective disorder" is applied inaccurately to the normal shift to lower energy levels in winter, leading people to believe they have a physical problem that should be addressed with various therapies or drugs.