What are the DSM-5 criteria for diagnosing mental disorders?

Definition

The DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, 5th Edition) provides standardized criteria for diagnosing mental disorders. A mental disorder is defined as a syndrome characterized by clinically significant disturbance in cognition, emotion regulation, or behavior, reflecting dysfunction in psychological, biological, or developmental processes.

DSM-5 Diagnostic Criteria

To diagnose a mental disorder using DSM-5, the following general criteria must be met:

1. Clinically Significant Disturbance: There must be a disturbance in cognition, emotion regulation, or behavior.
2. Dysfunction: The disturbance reflects a dysfunction in psychological, biological, or developmental processes.
3. Distress or Disability: The disturbance causes significant distress or impairment in social, occupational, or other important areas of functioning.
4. Not Culturally Expected: The disturbance is not merely an expectable or culturally approved response to a common stressor or loss.
5. Not Due to Substance or Medical Condition: The symptoms are not attributable to the physiological effects of a substance or another medical condition.

Worked Example: Major Depressive Disorder (MDD)

Step 1: Identify symptoms (at least 5 out of 9) present during the same 2-week period, representing a change from previous functioning. At least one symptom must be either (1) depressed mood or (2) loss of interest/pleasure.

Let $S$ be the set of symptoms:

$$ S = { \text{depressed mood}, \text{loss of interest}, \text{weight change}, \text{insomnia/hypersomnia}, \text{psychomotor changes}, \text{fatigue}, \text{worthlessness/guilt}, \text{concentration problems}, \text{suicidal thoughts} } $$

Suppose a patient reports:

• Depressed mood
• Loss of interest
• Fatigue
• Insomnia
• Worthlessness

This meets the criterion: $|S_{\text{present}}| = 5$.

Step 2: Assess distress/impairment:

• The symptoms cause significant distress or impairment in social or occupational functioning.

Step 3: Rule out other causes:

• Symptoms are not due to substance use or another medical condition.

Takeaways

• DSM-5 criteria require clinically significant disturbance, dysfunction, and distress/impairment.
• Diagnosis must rule out cultural norms, substance use, and medical conditions.
• Each disorder has specific symptom criteria, but all follow the general DSM-5 framework.