Depression and Problematic Substance Use

Depression and Problematic Substance Use

This is the first in a series of articles looking at the relationship between psychosocial functioning and problematic substance use.

Research suggests that over 80 per cent of problematic drug users may have a mental health issue, most commonly depression. Studies consistently report high levels of dual-diagnosis, or the co-existence of mental health and substance use problems. Drugs and alcohol may be used as a form of self-medication to help people to deal with depression and anxiety, and that anxiety can be further compounded by fears about feelings returning when drugs and alcohol are withdrawn. Substance use problems often evolve from efforts to self-medicate amongst those with mental health difficulties, and that this makes cessation of use that much harder.


Depression is therefore a risk factor for continued drug use and depressive disorders are the second most commonly diagnosed psychiatric disorder after dependent substance use amongst problematic drug users (PDUs). Where they also have poor levels of baseline social adjustment, high levels of depression can make PDUs ill-prepared to deal with life crises, other than by using drugs.

Substance use often has a reciprocal relationship with wider problems that are amplified by social impoverishment and poorly developed coping skills. In the absence of alternative sources of satisfaction, as a short-term solution to depression and wider mental health issues, drugs perpetuate the longer-term problems.

People with high depression scores on psychosocial assessments such as the Client Evaluation of Self and Treatment (CEST), have been found to engage in riskier drug taking behaviours and other risky health-related behaviours. Conversley, assessing and treating depression can reduce the probability of engagement in such risky behaviours. Higher depression levels measured at intake into drug treatment often result in lower levels of abstinence at discharge from treatment, regardless of whether substance use preceded onset of depression or whether individuals used drugs or alcohol to ‘self-medicate’ or ameliorate the effects of pre-existing depression symptoms. It is commonly found that depression poses a high risk for relapse. Depressive episodes may also reduce people’s confidence in avoiding relapse and may make people pessimistic about their ability to change their drug-using behaviour. As Bandura (2004) suggested:

People also rely on their physical and emotional states to judge their capabilities. They read their tension, anxiety, and depression as signs of personal deficiency. In activities that require strength and stamina, they interpret fatigue and pain as indictors of low physical efficacy ... People’s beliefs in their coping efficacy also affect their emotional life and how much stress, anxiety and depression they experience in threatening or disheartening situations. Those who believe they can manage threats and adversities view them as less inimical and act in ways that reduce their aversiveness [sic] or change them for the better.

This suggests that improving people’s self-efficacy (see later article) may also reduce their feelings of anxiety and depression. Anxiety is the subject of the next article.

<< All Posts