Alcohol and drug misuse are no longer confined to younger people, as the baby boomer cohort of older people shows the fastest rise in rates of mortality from drugs and from alcohol. This chapter provides an overview of substance misuse in older people, starting with its terminological, epidemiological, and pharmacological aspects. It goes on to detail clinical aspects that include screening, diagnosis, and presentations such as alcohol withdrawal, self-harm, drug intoxication, overdose, drug withdrawal, and psychosis.

Particular attention is paid to age-related syndromes such as alcohol-related brain damage – amnestic syndrome and alcohol-related dementia. The chapter also considers the relevance of comorbid physical disorders that can affect a range of pathologies and dysfunctions, particularly in gastro-intestinal, respiratory, cardiovascular, and neurological systems.

The organisation of care is also discussed, in order to highlight the importance of multi-agency working to provide a range of interventions that include liaison old age psychiatry and hepatology. The chapter goes on to cover medico-legal aspects as well as substance misuse and driving. It concludes with a section on discharge planning, emphasising the role of multidisciplinary teams in harm reduction – as well that of carers, non-statutory organisations, medical, and mental health services.