Co-occurring Psychiatric and Medical Conditions
What to know
Co-occurring disorders are common; integrated treatment is the standard. Understand common pairings: depression and alcohol, PTSD and substance use, ADHD and stimulants, anxiety and benzodiazepines. Know that suicide risk is elevated with substance use and must be assessed. Medical complications: alcohol (liver disease, pancreatitis, cardiomyopathy, Wernicke-Korsakoff), opioids (respiratory depression, overdose, infectious disease from injection), stimulants (cardiac, stroke, psychosis), tobacco (multiple cancers). Understand medication interactions (e.g., benzodiazepines + opioids = respiratory depression). Recognize trauma-informed care and the risk of self-medication. Know that psychiatric symptoms may improve with abstinence (e.g., substance-induced mood disorder).
Traps
Questions assume treating one disorder will resolve the other. Watch for items that recommend benzodiazepines for anxiety in patients with SUD without caution - generally avoided. Don't miss substance-induced psychiatric presentations versus independent disorders. Note that opioid + benzodiazepine co-prescribing raises overdose risk.
Rule of thumb
Treat both disorders concurrently, not sequentially. If psychiatric symptoms resolve with abstinence, consider a substance-induced disorder; if they persist, evaluate for an independent disorder.
Worked example
A patient with alcohol use and depression improves after 4 weeks of abstinence. This suggests a substance-induced depressive disorder; continue monitoring before initiating long-term antidepressant therapy.