Substance misuse other than alcohol in older adults

Three broad categories (textbook classification). (a) Medications — prescribed (benzodiazepines, opioids, Z-drugs, anticholinergics) and non-prescribed / over-the-counter (codeine, antihistamines, laxatives, decongestants); (b) socially sanctioned psychoactive substances — tobacco, caffeine; (c) illicit substances — cannabis, opioids, cocaine.

Changing epidemiology. There is a growing trend of substance misuse in the elderly, driven by a generation of lifetime drug users now entering old age. Prescribed benzodiazepine and opioid misuse remains far commoner than illicit drug use. In India, traditional patterns include opium and doda-post use in Rajasthan and Punjab, and cannabis (bhang, ganja) in older men.

Why it is missed. Older people rarely present complaining of substance misuse — they present with associated physical problems. Symptoms are wrongly attributed to ageing or dementia (falls, confusion, incontinence, self-neglect, weight loss). Add stigma, screening tools validated in the young, and the absence of work or legal markers in a retired person.

Age-specific vulnerability. Reduced hepatic and renal clearance, reduced lean body mass and total body water, increased CNS sensitivity, and polypharmacy with drug interactions — so much smaller quantities produce toxicity and withdrawal than in younger adults.

Assessment. Sensitive but persistent enquiry plus an informant history, supported by standardised screening tools. Review every prescribed and over-the-counter drug, look for multiple prescribers and early repeat requests, and actively treat comorbid depression, pain and insomnia, which perpetuate the disorder. Examine social factors — housing and a social network of substance users.

Management. A multistage, integrated physical + psychological + social package delivered concurrently, not consecutively, in a form acceptable to older people. Detoxification where physical dependence exists. Age-specific, non-confrontational, supportive group programmes retain older patients better than mixed-age confrontational programmes — one study found confrontational programmes achieved half the abstinence of those promoting self-esteem, tolerance and peer relationships. Follow with rehabilitation, aftercare and relapse prevention.

Cannabis is the fastest-growing substance of misuse in adults aged ≥65 (2023–2025). Recent national survey data show a sharp rise in past-year use, and current reviews link it in older adults to falls, orthostatic hypotension, tachyarrhythmia, cognitive impairment and cannabis-induced psychosis, compounded by drug interactions and unregulated cannabidiol products. In parallel, the 2023 AGS Beers Criteria strengthened the caution against combining opioids with benzodiazepines or gabapentinoids in older adults. If asked for 15 marks, add: screening instruments (ASSIST, DAST, Severity of Dependence Scale); detailed opioid misuse and opioid use disorder management with buprenorphine/methadone in the elderly; withdrawal syndromes by substance; Indian data from the NDDTC-AIIMS "Magnitude of Substance Use in India" report and the Nasha Mukt Bharat Abhiyaan; the interface with elder abuse and financial exploitation; and prevention through rational prescribing and deprescribing.