From the Guidelines
Major depressive disorder, as defined by the DSM-5, requires at least five symptoms to be present during the same 2-week period, with at least one symptom being either depressed mood or loss of interest/pleasure, and these symptoms must cause clinically significant distress or impairment in functioning 1. The specific symptoms of major depressive disorder include:
- Depressed mood most of the day, nearly every day
- Markedly diminished interest or pleasure in almost all activities
- Significant weight loss or gain (more than 5% of body weight in a month) or changes in appetite
- Insomnia or hypersomnia nearly every day
- Psychomotor agitation or retardation observable by others
- Fatigue or loss of energy
- Feelings of worthlessness or excessive/inappropriate guilt
- Diminished ability to think or concentrate, or indecisiveness
- Recurrent thoughts of death, suicidal ideation, or suicide attempts These symptoms cannot be attributable to physiological effects of substances or medical conditions, and are not better explained by other psychiatric disorders, as stated in the DSM-5 criteria 1. It is essential to note that the severity of depressive disorders can be based on symptom count, intensity of symptoms, and/or level of impairment, and that mild depression might be defined as 5 to 6 symptoms that are mild in severity, while severe depression might be characterized by all of the depressive symptoms listed in the DSM-5 or severe impairment in functioning 1. Understanding these criteria is crucial for proper diagnosis and treatment planning, as accurate identification of major depressive disorder guides appropriate therapeutic interventions, and the DSM-5 criteria provide a standardized framework for diagnosing and assessing the severity of major depressive disorder 1.
From the Research
DSM-5 Criteria for Major Depressive Disorder
The DSM-5 criteria for major depressive disorder (MDD) are defined as five or more of the following symptoms in the past 2 weeks, during which at least one is depressed mood or loss of interest or pleasure 2. The symptoms include:
- Depressed mood
- Diminished interest or pleasure in activities
- Significant weight loss or gain, or decreased or increased appetite
- Insomnia or hypersomnia
- Psychomotor agitation or retardation
- Fatigue or loss of energy
- Feelings of worthlessness or excessive or inappropriate guilt
- Poor concentration or indecisiveness
- Recurrent thoughts of death or suicidal ideation, plan, or attempt
Diagnosis and Severity
Depression diagnosis requires five or more symptoms, with one of them being either depressed mood or anhedonia (loss of interest or pleasure) 3. The severity of depression is a continuous variable and can be assessed using scales such as the Hamilton Depression Rating Scale (HAMD). The DSM-5 symptoms can help discriminate between severely depressed (SD) and moderately depressed (MD) patients, as well as between MD and non-depressed (ND) subjects.
Symptom Criteria
The diagnostic criteria for depression were developed based on clinical experience rather than empirical study 4. However, studies have examined the psychometric properties of the DSM criteria for major depression, finding that all criteria are significantly associated with the diagnosis 4. Some symptoms, such as insomnia, fatigue, and impaired concentration, which are also criteria for other disorders, perform as well as the criteria unique to depression.
Limitations of DSM Criteria
The DSM criteria for major depression may not capture all important features of the disorder 5. Compared to textbook descriptions of clinical depression, the DSM criteria are narrower for some symptoms, such as mood and cognitive content, and do not include other symptoms and signs, such as changes in volition/motivation, slowing of speech, anxiety, and depersonalization/derealization. This suggests that the DSM criteria should be understood as an index of the disorder rather than the disorder itself.