What are the key signs and screening tools to identify substance use in patients?

Identifying Substance Use in Patients

Use the single-question screen "How many times in the past year have you used an illegal drug or used a prescription medication for nonmedical reasons?" as your initial screening tool, which demonstrates 90-100% sensitivity and 74% specificity for substance use disorders. 1

Initial Screening Strategy

Universal screening is justified in all patients despite insufficient evidence that screening alone improves outcomes, based on the high prevalence, substantial morbidity and mortality associated with substance use, and proven effectiveness of early identification. 2, 1 The American Academy of Family Physicians recommends screening annually in established patients. 1

Primary Screening Tool

• Ask the single question: "How many times in the past year have you used an illegal drug or used a prescription medication for nonmedical reasons?" 2, 1
• If clarification is needed, add: "For instance, because of the experience or feeling it caused." 2
• Any response of 1 or more times is considered a positive screen requiring further assessment. 1

Secondary Assessment for Positive Screens

When the single-question screen is positive, administer the Drug Abuse Screening Test-10 (DAST-10) to quantify risk level, which demonstrates 90-100% sensitivity and 77% specificity. 2, 1

DAST-10 Questions and Scoring

The DAST-10 includes these 10 questions (give one point for each "yes" answer, except question 3 which is one point for "no"): 2

1. Have you used drugs other than those required for medical reasons?
2. Do you use more than one drug at a time?
3. Are you always able to stop using drugs when you want to? (reverse scored)
4. Have you ever had blackouts or flashbacks as a result of drug use?
5. Do you ever feel bad or guilty about your drug use?
6. Does your spouse (or parents) ever complain about your involvement with drugs?
7. Have you neglected your family because of your use of drugs?
8. Have you engaged in illegal activities to obtain drugs?
9. Have you ever experienced withdrawal symptoms (felt sick) when you stopped taking drugs?
10. Have you had medical problems as a result of your drug use (e.g., memory loss, hepatitis, convulsions, bleeding)?

Scoring interpretation: 2, 1

• 0 points = low risk: Reinforce healthy behavior
• 1-3 points = moderate risk: Monitor and reassess patient
• >3 points = substance abuse or dependence: Requires intervention

Risk Stratification After Positive Screen

Stratify positive screens into three categories to guide intervention intensity: 1

Hazardous Use

• Definition: Infrequent use with potential health consequences, risk of dependence, or legal repercussions 1
• Management: Brief counseling using motivational interviewing and ongoing assessment 1

Substance Abuse

• Diagnostic criteria (one or more within 12 months): 1
  • Recurrent use causing failure to fulfill major role obligations
  • Recurrent use in physically hazardous situations
  • Recurrent substance-related legal problems
  • Continued use despite persistent social/interpersonal problems
• Management: Brief counseling, negotiate a plan, and close follow-up 1

Substance Dependence

• Diagnostic criteria (three or more within 12 months): 1
  • Tolerance
  • Withdrawal
  • Loss of control
  • Persistent desire to quit
  • Time spent obtaining/using/recovering
  • Reduced activities
  • Continued use despite problems
• Management: Brief counseling, referral for specialty treatment, and consideration of pharmacotherapy 1

Clinical Signs of Drug-Seeking Behavior

Recognize that apparent "drug-seeking" behavior often represents legitimate medical needs, including pseudoaddiction from undertreated pain, therapeutic dependence, or anxiety about symptom recurrence. 3 However, true drug-seeking behaviors include: 4, 5

• Emergency calls or visits near the end of office hours 4
• Refusal to undergo appropriate examination, testing, or referral 4
• Repeated "loss" of prescriptions 4
• Tampering with prescriptions 4
• Reluctance to provide prior medical records or contact information for other treating providers 4
• "Doctor shopping" (visiting multiple prescribers to obtain additional prescriptions) 4
• Escalating use patterns 5

Role of Urine Drug Testing

Routine urine drug testing is not recommended for screening purposes, but can be used selectively to support a suspected diagnosis, assess for polysubstance use, or monitor treatment response. 2, 1

High-Risk Substance Considerations

Not all substance use carries equal risk. Heroin, methamphetamine, and crack cocaine are associated with intrinsically high risk of harm to self and others, requiring more aggressive intervention even with infrequent use. 2, 1 In contrast, ecstasy and marijuana have intrinsically lower (but not negligible) risk of harm, though they can still represent risky choices in the context of young age, genetic predisposition to dependence, unstable social circumstances, heavy use, or impaired coping mechanisms. 2

Assessment of Comorbidities

In patients with positive screens, assess for: 1, 3

• Mental illness (depression, anxiety, bipolar disorder) 1
• Intimate partner violence (rates exceed 50% in populations with substance use disorders) 3
• Infectious disease risks: HIV, hepatitis, STDs, and tuberculosis 3
• Suicidal ideation (increased risk in patients with substance use disorders) 6

Critical Pitfall to Avoid

Never allow concerns about being manipulated to cloud clinical judgment about legitimate pain medication needs. 3 Pseudoaddiction occurs when patients exhibit behavioral changes mimicking addiction but are actually secondary to inadequate pain control, and patients seek alternate sources or increased doses because prescribed analgesia provides insufficient relief. 3 Undertreating acute pain can lead to decreased responsiveness to opioid analgesics, making subsequent pain control more difficult. 3