Diagnosis of Substance Use Disorder

Overview

Substance Use Disorder (SUD) is a medical condition characterized by an inability to control the use of a substance despite harmful consequences. It affects an individual’s brain and behaviour, leading to the compulsive use of drugs or alcohol. Diagnosing SUD involves a comprehensive assessment of behavioural, psychological, and physiological criteria.

Diagnostic Criteria

The diagnosis of SUD is primarily based on criteria outlined in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), published by the American Psychiatric Association. The DSM-5 criteria for SUD include:

DSM-5 Criteria

The DSM-5 categorizes SUD into mild, moderate, or severe based on the number of criteria met. There are 11 criteria, and they are grouped into four categories:

  1. Impaired Control:
    • Taking the substance in larger amounts or over a longer period than was intended.
    • Persistent desire or unsuccessful efforts to cut down or control substance use.
    • Spending a great deal of time obtaining, using, or recovering from the substance.
    • Craving, or a strong desire or urge to use the substance.
  2. Social Impairment:
    • Recurrent substance use resulting in a failure to fulfill major role obligations at work, school, or home.
    • Continued substance use despite having persistent or recurrent social or interpersonal problems caused or exacerbated by the effects of the substance.
    • Important social, occupational, or recreational activities are given up or reduced because of substance use.
  3. Risky Use:
    • Recurrent substance use in situations in which it is physically hazardous.
    • Continued substance use despite knowledge of having a persistent or recurrent physical or psychological problem that is likely to have been caused or exacerbated by the substance.
  4. Pharmacological Criteria:
    • Tolerance, as defined by either of the following:
      • A need for markedly increased amounts of the substance to achieve intoxication or desired effect.
      • A markedly diminished effect with continued use of the same amount of the substance.
    • Withdrawal, as manifested by either of the following:
      • The characteristic withdrawal syndrome for the substance.
      • The substance (or a closely related substance) is taken to relieve or avoid withdrawal symptoms.

Severity Specifiers

  • Mild: Presence of 2-3 criteria.
  • Moderate: Presence of 4-5 criteria.
  • Severe: Presence of 6 or more criteria.

Assessment Tools

Several assessment tools and screening instruments are used to diagnose and evaluate the severity of SUD:

  1. Screening Tools:
    • CAGE Questionnaire: A quick screening tool with four questions related to cutting down, annoyance by criticism, guilty feelings, and eye-openers.
    • AUDIT (Alcohol Use Disorders Identification Test): A 10-item questionnaire developed by the World Health Organization to screen for harmful alcohol use.
    • DAST (Drug Abuse Screening Test): A self-report instrument for assessing drug use and related problems.
  2. Structured Interviews:
    • Structured Clinical Interview for DSM-5 (SCID-5): A semi-structured interview guide for making DSM-5 diagnoses, including SUD.
    • Addiction Severity Index (ASI): A comprehensive interview that assesses multiple areas of functioning, including medical, employment, drug and alcohol use, legal, family/social, and psychiatric status.

Physical Examination and Laboratory Tests

  • Physical Examination: To identify signs of substance use or complications (e.g., track marks, liver disease).
  • Laboratory Tests:
    • Urine or blood tests to detect the presence of drugs or alcohol.
    • Liver function tests, complete blood count (CBC), and other relevant tests to assess the impact of substance use on physical health.

Differential Diagnosis

It is essential to differentiate SUD from other conditions that may present with similar symptoms, such as:

  • Mental health disorders (e.g., depression, anxiety).
  • Medical conditions (e.g., chronic pain, liver disease).
  • Other substance use or abuse (e.g., prescription medications).

Conclusion

The diagnosis of SUD requires a thorough assessment using DSM-5 criteria, validated screening tools, structured interviews, physical examination, and laboratory tests. Early and accurate diagnosis is crucial for effective treatment and management, which may include behavioral therapies, medications, and support services.