A co-existing problem occurs when people have a mental illness and at the same time use substances in ways that could be harmful. This is sometimes also called “concurrent disorders.”
A co-existing problem occurs when we have a mental health problem and, at the same time, use substances in ways that could result in significant harm. It is not known how many people experience this dual problem (sometimes called a 'concurrent disorder'). But a national study in the United States, looking at mental illness alongside substance use in a lifetime, suggests about half of the people experiencing a mental illness also struggle with a substance use problem, and vice versa.