Mental illness and addiction often overlap. In fact, nearly 9 million people have a co-occurring disorder according to the Substance Abuse and Mental Health Services Administration (SAMHSA). Yet, only 7 percent of these individuals get treatment for both conditions. And nearly 60 percent receive no treatment at all.
Comorbidity refers to the fact that two conditions, such as a specific mental health disorder and a substance use disorder, often co-exist together. What this means is that in many people with addictions, there is an underlying mental health issue as well. While neither condition actually causes the other, they do often exist together.
To better understand how comorbidity is possible, it helps to recognize that both are chronic brain disorders. In other words, when someone struggles with an addiction, their brain has been permanently rewired by the substance they abused. This causes the brain to function differently than before.
The changes that take place in the brain due to substance abuse occur in the same brain areas that are impacted by depression, anxiety, schizophrenia, and bipolar disorder. So, it should not be surprising that there is a high rate of comorbidity between addiction and other mental illnesses.
There are some mental health issues that can actually increase the risk factors for substance abuse. The result is some people with mental illnesses will turn to alcohol or drugs to cope with the pain of their mental health issues.