Individuals who struggle with addiction also frequently have mental health problems. The prevalence of depression and anxiety among addicts is particularly high. One researcher has speculated that these conditions may have a similar root cause in the brain, and he is working to develop a medication that will provide substance abuse help for millions of Americans with co-occurring conditions.

Shafiqur Rahman, a pharmacology professor at South Dakota State University, believes that a single receptor in the brain may be at the heart of addiction to nicotine and alcohol as well as mental disorders like depression and anxiety, according to CNBC.

He is currently studying different substances that he believes will stimulate this receptor, causing it to take away the reward responses associated with smoking and drinking. This may also help alleviate some of the symptoms associated with some mood disorders.

He told the news source that he has found one substance called lobeline, which has shown some promise in early trials.

A majority of the people who seek substance abuse help also have some form of mental disorder, according the Substance Abuse and Mental Health Services Administration.