Experts examining the relationship between substance use and mental health disorders say drug use may often be the first red flag that parents and healthcare providers notice when a child is dealing with mental illness symptoms. According to psychologists at Northeastern University, people with depression, anxiety, schizophrenia or bipolar disorder tend to use alcohol and drugs more than the general population, and substance use can delay diagnosis and treatment of underlying mental health conditions.
The federal Substance Abuse and Mental Health Services Administration reports that approximately 21.5 million adults in the United States have a co-occurring disorder, also known as a dual diagnosis of mental health and substance use disorder. Robert Leeman, professor and chair of Northeastern’s department of public health and health sciences, noted that using substances can exacerbate symptoms associated with mental health conditions such as schizophrenia and could increase the risk of violence, particularly when substance use is heavy and involves drugs associated with psychosis such as cannabis and methamphetamine.
People may start using drugs and alcohol to self-medicate feelings of being out of control, jumpy, depressed or anxious. However, starting substance use in adolescence, particularly the early teens, also increases the probability of having a mental health disorder later. Since mental health conditions such as schizophrenia or bipolar disorder tend not to manifest until a child is in their late teens or twenties, family and healthcare professionals may attribute a teen’s problems to alcohol and drug use without recognizing an underlying condition. When a child has a mental illness alongside substance abuse, the family and health professionals often focus first on substance abuse because it tends to be the most disruptive to those around them.
Experts note that approximately 17 years ago, people who worked with patients with substance abuse disorder and those with mental health illnesses operated in separate systems. Kristen Lee, a Northeastern teaching professor in behavioral science, emphasized that co-occurring disorders should be treated concurrently to help a person regain insight and functioning. At minimum, the history of substance use should be considered when treating mental health conditions to avoid treatment that will exacerbate substance use.
This article is an AI-assisted summary. All facts and figures are drawn from the original report: https://news.northeastern.edu/2025/12/22/nick-reiner-drug-use/