Back to basics—substance use assessments

The seasoned prescriber will know the long-term benefits of taking an initial, comprehensive substance use history before prescribing psychoactive medications. Too often (and sometimes too late), busy practitioners may realize that had they taken a little more time, they would not be receiving increasingly frequent requests from a patient for more of those “painkillers” or “nerve pills.”


Screening and clinical assessment are not the same. Screening should occur when a patient first presents, and may include screening tools, biological testing (e.g. urine toxicology, lab work for serum indicators of substance/alcohol use), physical and mental state examination. Registrants should consider having the following screening tests available in their EMR, or otherwise readily accessible: CAGE (brief 4 –item tool), Full AUDIT (Alcohol Use Disorders Identification Test), DAST (Drug Abuse Screening Test), CRAFFT (Car Relax Alone Forget Friends Trouble; for young people and their drug and alcohol involvement). 

Clinical assessment

Clinical assessment determines the impact substance use has, or has had, on the patient, and includes the ongoing assessment of the patient’s physical well-being, mental and social functioning. Clinical assessment is recommended whenever initiating psychoactive medications, and is essential to continue throughout longer-term prescribing. 

Clinical assessment includes:

  • Use of legal, illegal, prescribed and over-the-counter substances: how much, how often, route of use, length of use, detox or treatment experiences, periods of abstinence
  • The patient’s view: does the patient think that they have, or have had, a problem with substance use?
  • Psychiatric history: admissions, suicide attempts, outpatient psychiatric review
  • Impacts of substance use on different aspects of life such as work, family, and relationships
  • Medical history of related complications such as hepatitis, septicemia, abscesses, cirrhosis, endocarditis, osteomyelitis, and unintentional overdose
  • Family history of substance use (often a significant “red flag”)
  • Social history including lifestyle, criminal involvement, unemployment
  • Physical examination, specifically assessing for presence of stigmata of substance use disorder
  • Drug testing, lab work
  • Urine drug screening (point-of-care dipstick) and perhaps breathalyzer

Clinical assessments may be daunting at first, but they quickly become routine if conducted on all patients in a non-judgmental manner, and may promote an open dialogue, which strengthens the patient-physician relationship.