In numerous studies of adolescents and young adults, researchers have found that young people with mental health problems are more likely than those without these issues to also have alcohol or substance use problems. In fact, adolescents receiving treatment for depression are more likely than their non-depressed peers to experience substance abuse problems. The converse of this phenomenon also appears to be true. Among youth living in the community, approximately 20 percent of those who use alcohol or other drugs are estimated to also experience depression at the same time. They are also estimated to be four times more likely than their non-using peers to have a disruptive behavior diagnosis, like conduct disorder. Experiencing both mental health and substance abuse problems is known as having a co-occurring disorder.
These findings have been echoed in several surveys of college students. In analyzing data from the Spring 2002 National College Health Survey (NCHS), the National Center on Addition and Substance Abuse at Columbia University found that students experiencing depression were more likely than their non-depressed peers to use alcohol and other drugs:
- Alcohol use was more likely among students who reported being depressed or diagnosed with depression in past school year. Binge drinking was more likely among students who reported being depressed and among those who felt suicidal or had attempted suicide in the past year.
- Smoking was much more likely among students who reported being depressed or diagnosed with depression in the last school year. It was also much more common among students who felt suicidal or had attempted suicide in the past year.
- Marijuana use was more likely among students who reported being depressed and diagnosed with depression in the past school year. It was also much more common among students who felt suicidal in the past year or had attempted suicide.
Multiple studies have also found that young people with one mental illness are more likely than their peers to have other mental illnesses or be at risk for experiencing them at some point in the future. Several studies conducted across individual campuses have found that students with depression, for example, are more likely to experience other mental health problems like anxiety or eating disorders.
Students with poor mental health also appear to be more likely to engage in risky behaviors, further endangering their health, productivity, and overall wellbeing. In a recent survey of college students conducted by the Harvard College Alcohol Study (CAS), researchers found that survey respondents considered to have poor mental health or depression (PMHD) were more likely than students without PMHD to report drinking, drinking to get drunk, and to experience drinking-related harms, such as falling behind in work, vandalizing, having unsafe sex, and overdosing.
The direction of these relationships and the extent to which one disorder may precede or cause another is still being investigated. But despite the gaps in knowledge about the progression of co-occurring disorders, it is important for campuses to consider that mental health, suicide, and alcohol and other drug use issues do not often occur in isolation; there is a strong likelihood that students experiencing one problem will also experience another. Therefore, addressing mental health issues through an overall comprehensive approach is one way of responding to these co-occurring disorders.