When it comes to addiction, it's not often a problem on its own. In many cases, there can be other mental health issues present (sometimes referred to as a dual diagnosis) which need to be identified and treated accordingly for the best outcome, says Chambless Johnston, CEO of East Tennessee Recovery Centre.

As a doctor who specializes in addiction treatment, Dr. Johnston of Johnston City, Tennessee, understands that it's important to establish from the start that addiction is in itself a mental illness. Addiction can change how a person functions and interferes with their ability to work or maintain relationships. In some cases, the drugs used can go beyond behavioral changes and cause physical issues affecting heart rate and breathing, which can lead to overdose deaths. Meanwhile, the large amounts of neurotransmitters responsible for pleasure released from drug use can rewire the brain to seek out more of it despite the risks.

High Rate of Substance Dependent Patients Have Comorbid Diagnoses

A comorbid condition is one that exists alongside another. However, while those who abuse substances can develop other mental illnesses as a result, the existing mental health conditions may be a driver for the addictive behavior. Statistics show that about 50% of people who have a mental illness will also develop dependence on substances at some point and the opposite scenario is also true.

Among the mental illnesses that drive substance abuse, anxiety-related illnesses have high rates, explains Dr. Chambless Johnston. Research shows that these types of disorders (which include PTSD) are commonly associated with drug abuse, while depression and bipolar disorder also are found alongside substance abuse often. In fact, a study of comorbid psychiatric disorders in substance dependent patients suggests the most common comorbid illnesses with addiction are depressive disorders. The same study of inpatients shows more than 80% of the subjects had at least one comorbid mental disorder, with about a third having major depression.

Particular Mental Disorders May Dictate Which Drugs are Abused

Mental illnesses tend to pair with certain abused drugs. For example, those with ADHD may develop a habit of taking stimulants that are used to treat the disorder, while those with depression tend to turn to alcohol — which is in itself a depressant and can worsen symptoms in the long-term. Meanwhile, patients with eating disorders such as anorexia may become dependent on drugs that lower appetite.

Knowing some key information can help a doctor identify a co-existing condition apart from addiction, which is considered a mental illness on its own. There are common risk factors for both addiction and developing mental illnesses — and one doesn't necessarily cause the other, explains Chambless Johnston. For example, there can be genetic factors that contribute to both — there's also some evidence that shows stress and trauma can be passed down and cause genetic changes that become risk factors for future generations.

Age When Substance Abuse Began Important Factor

Using drugs at an earlier age tends to raise the risk of addiction or mental illness later in life. The abuse of a substance can cause brain damage more easily during development.

There are other factors that dictate how susceptible to addiction a person may be — including the effect a particular drug has on them, namely their tolerance for it and how good it makes them feel after taking it (the "high”).

Environmental factors must also be considered to uncover the triggers for substance abuse or a mental health disorder. There may be a particularly traumatic experience contributing to both, as well as an ongoing stressful environment.

Behavioral Clues in Diagnosing Comorbid Mental Disorders

While attempting to diagnose a comorbid mental condition, there are other clues that health professionals can look to, explains Chambless Johnston. These can include showing more anger or aggression, developing sleeping issues, as well as mood swings, unexplained fatigue, and feelings of guilt that are out of the ordinary. Mental illnesses can also affect a person's libido and lead to suicidal thinking.

What this comes down to is the need for an individualized treatment plan that considers the addiction and the mental illnesses in a comprehensive manner for the best outcomes, says Dr. Chambless Johnston. The treatments can include techniques such as cognitive behavioral therapy. Medication assisted treatment (MAT) can also be an option depending on the situation. Some medications have also been shown to treat both dependency on a drug as well as helping provide relief from a mental disorder — for example, Wellbutrincan helpcurb nicotine use as well as depression.

Treatment a Major Step Towards Recovery, Says Dr. Chambless Johnston

The important first step is learning how to recognize and acknowledge substance abuse or other mental illnesses in order to properly address it, says Chambless Johnston.

Having treatment does not mean a person is cured and does not guarantee a person will not start using the drug again (relapse.) However, statistics show that those who receive proper treatment will have a better outcome and that treatment can be adjusted in the case of a relapse to ensure continued success.