The most accepted description of the symptoms of depressive disorders are those published in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM 5), published by the American Psychiatric Association. A symptom is any subjective evidence of a disorder — in other words, a phenomenon that is experienced by the individual affected by the condition.
Before discussing specific symptoms, it is important to differentiate depressive episodes and depressive disorders. Depressive episodes are specific time periods during which one experiences the signs and symptoms of depression. Depressive disorders are conditions diagnosed based upon the occurrence of depressive episodes. The diagnosis of major depressive disorder is made when one meets the diagnostic criteria for a major depressive episode.
Major Depressive Episodes
Major depressive disorder is diagnosed when symptoms have been experienced almost every day for at least two weeks. The symptoms must be more intense than the normal fluctuations in mood that all of us experience in our daily lives. There are several criteria that must be met for a diagnosis of major depressive disorders as outlined in DSM 5.
The first criterion is that one must experience a specific number of depressive symptoms for a diagnosis to be made. DSM 5 lists nine possible symptoms of depression. Five are needed for a diagnosis of major depression, and at least one of these five has to be either depressed mood or loss of interest or pleasure in activities. The symptoms of depression can manifest as mood symptoms, physical symptoms or cognitive (thinking) symptoms.
The first two possible symptoms of depression are mood symptoms. These are depressed mood and anhedonia. To meet the criteria for depressed mood, one must feel depressed most of the day almost every day. This mood state might be described as feelings of sadness, emptiness or hopelessness. Anhedonia means decreased ability to experience pleasure. For major depressive disorder, one must experience markedly diminished interest or pleasure in all or almost all activities most of the day nearly every day. As stated above, for a diagnosis of depression, one must have one or both of these symptoms. Many people experience both.
Other possible symptoms of depression are physical symptoms that impact bodily function. One of these is either significant weight gain or weight loss when not dieting. Sleep disturbance is another, manifested by the inability to sleep or oversleeping nearly every day. Increased or decreased psychomotor behavior (bodily movement) can be a symptom. This is known as psychomotor agitation (trouble sitting still or jittery) or retardation (slowed movements). Finally, daily fatigue or loss of energy is a physical symptom of depression.
The cognitive symptoms of depression may manifest as frequent daily thoughts that one is worthless or thoughts and feelings of inappropriate guilt. Another cognitive symptom can be diminished ability to think or concentrate or indecisiveness nearly every day. Lastly, recurrent thoughts of death and/or thoughts of committing suicide can be a depressive symptom.
If you (or someone you know) are having thoughts of suicide or self-harm, this is an emergency and immediate evaluation by a medical or mental-health professional is necessary. Several options exist for getting help immediately and are listed in the overview article. One of these is the National Suicide Prevention Lifeline. This is a free, 24-hour hotline available to those experiencing emotional crises or having thoughts of harming themselves or others. The number is 1-800-273-TALK (8255).
In addition to symptoms discussed above, several additional criteria must be met for a diagnosis of a major depressive disorder. One is that the symptoms must cause clinically significant distress or impairment in social, occupational or other important areas of functioning. In other words, the symptoms are more intense than normal mood fluctuations and interfere with the functioning of life. Additional criteria are that the episode is not due to the effects of a substance or medical condition or better explained by another psychiatric disorder. Finally, the individual must never have experienced a manic episode or a hypomanic (milder mania) episode. If there has been a prior manic episode the diagnosis would be one of the bipolar disorders.