Substance Use Disorder
Substance use disorder is a pattern of substance use causing significant impairment or distress, defined per DSM-5 and treated per the ASAM/SAMHSA National Practice Guideline.
Symptoms
DSM-5 lists 11 criteria across four groupings -- impaired control, social impairment, risky use, and pharmacological effects (tolerance, withdrawal) -- with severity graded as mild (2-3 criteria), moderate (4-5), or severe (6+).
Causes and risk
A combination of genetics, adverse childhood experiences, early initiation of substance use, family history, and social/environmental factors.
How it is evaluated
Diagnosis follows DSM-5 criteria assessed over a 12-month period; screening tools help identify use patterns that warrant fuller evaluation.
Treatment
Medication combined with psychosocial treatment is the standard of care; for opioid use disorder specifically, methadone and buprenorphine are first-line and reduce overdose mortality, per the ASAM/SAMHSA guideline, which also states that medication should not be withheld if a patient declines counseling.
When to seek care
Signs of overdose (unresponsiveness, slow or stopped breathing, blue lips or fingertips) are a medical emergency -- call 911 immediately, administer naloxone if available, and stay with the person, since re-overdose can occur up to about 90 minutes after naloxone wears off. Withdrawal from alcohol or sedatives can also be medically dangerous and should be managed under clinical supervision rather than stopped abruptly alone.