Substance Misuse Psychiatry

Abstract

Clinicians in all areas of medicine are likely to encounter people with substance misuse issues, so an understanding of the key issues is essen­tial. Human beings have used intoxicating substances, such as alcohol, nicotine, cannabis, and heroin, for millennia. Motivations might include experimentation, pleasure, social enhancement, or for physical or psy­chological pain management. Some people who use these legal and illegal substances experience problems related to their use, including loss of control, adverse consequences, withdrawals or cravings, damaged end organs, risky behaviour, and premature death. Substance misuse impacts not only on individual physical and mental health but also upon families and wider society by increased healthcare, criminal justice, social ser­vices, and unemployment costs. Drug and alcohol problems affect between 10% and 25% of the popu­lation each year, and up to 35% of people have ever used illicit drugs. Alcohol, an intoxicating sedative, is the most commonly used drug, with 25% of the UK population drinking above ‘low-risk’ limits. In England in 2010 there were an estimated 300 000 opiate, crack-cocaine, and inject­ing drug users, and only half were in treatment. Substance misuse is commonly associated with physical and mental health co-morbidity. The prevalence of co-existing mental health and substance use problems (termed ‘dual diagnosis’) may affect between 30% and 70% of those presenting to healthcare and social care settings. In general, four interrelationships in dual diagnosis are recognized: • substance use leading to social problems and psychological symptoms not amounting to a diagnosis • substance use leading to social dysfunction and secondary psychiatric and physical illness • substance use exacerbating an existing mental or physical health prob­lem and associated social functioning • primary psychiatric illness precipitating substance misuse which may also be associated with physical illness and affect social ability. Given the array of substance misuse problems, an individual treat­ment approach is essential and may involve psychological, pharmaco­logical, and social intervention. An empathic, non-judgemental clinical approach is essential to engage people with substance misuse problems. Motivational interviewing is an evidence-based talking therapy to help people in denial about their problems make changes for themselves and avoids imposing change prematurely.