Mental Illness and Substance Abuse: The Intersection

What is mental illness?

A mental illness is loosely defined as “a wide range of conditions that affect mood, thinking, and behaviour.” Meanwhile, a substance abuse disorder is defined as “a mental disorder that affects a person's brain and behaviour, leading to a person's inability to control their use of substances such as legal or illegal drugs, alcohol, or medications.”

The four D’s of mental illness are deviance, dysfunction, distress, and danger. Mental illnesses are deviant from normal behaviour and thought patterns, they cause dysfunction and distress to the person suffering (also to those around them), and they can make a person dangerous, to themselves and others.

How are mental illnesses and substance abuse issues interrelated?

Mental illness and substance abuse often go hand in hand, and here is why; more often than not, a person who abuses substances such as alcohol, marijuana, opioids, etc, does so as a form of self-medication. The reasons for doing so range from chronic pain treatment to just experiencing a moment of peace from the chaos of their minds, for the high. Many substances put your mind at ease, even if it is temporary, but they all take a toll on your mental health, as soon as the high is over. The after-effects of stimulant drugs such as nicotine and cocaine are bouts of depression, anxiety, and paranoia. Reportedly, small doses of cocaine can make the user feel euphoric, energetic, talkative, and hypersensitive. The drug can also temporarily decrease the need for food and sleep, but long term, it can trigger psychosis and schizophrenia.

What are Co-Occurring Disorders?

These are the median between mental illness and substance abuse disorders. Co-occurring disorders ( also referred to as a dual diagnosis or comorbidity ) are defined as “The coexistence of both a mental illness and a substance use disorder.” There are specific substances that are more likely abused by people with certain mental disorders. For example, according to the DSM-5, an alcohol use disorder is more likely to take place in people with pre-existing bipolar disorders and/or schizophrenia. Opioid use and abuse is linked with depressive disorders. Nicotine addiction, or a tobacco abuse disorder, is commonly seen amongst eating-disordered people.

People with mental illness are more likely to develop drug abuse disorders. According to the National Institute on Drug Abuse, “Roughly half of the individuals who have either a mental illness or substance abuse disorder will have the other at some point in their lives.” Several pathways result in co-occurring disorders; self-medication habits with drugs and/or alcohol for anxiety, depression, or PTSD develop into full-blown addictions, or a consequence of consistent drug abuse turns out to be a mental illness such as depression, anxiety, or more extreme disorders.

To conclude, both mental illness and substance abuse disorders can exist exclusively from each other, but it is also feasible for them to lead to one another, and even coexist.

What is it like to live with a co-occurring disorder?

Like most mental illnesses, there is a severity scale of co occurring-disorders, ranging from category I-IV.

The Four Quadrants Model (National Association of State Mental Health Program Directors & National Association of State Alcohol and Drug Abuse Directors, 1999) classifies clients into four basic groups based on the extremity of their symptoms:

Category I: Less severe mental disorder/ less severe substance disorder (wherein both the mental and substance disorder are at a similar level of intensity and are typically manageable).

Category II: More severe mental disorder/ less severe substance disorder (higher severity of mental illness than substance abuse).

Category III: Less severe mental disorder/ more severe substance disorder (higher level of drug abuse than mental illness).

Category IV: More severe mental disorder/ more severe substance disorder (more or less equally high severity of both mental and substance disorder).

People living with this disorder are in constant mental turmoil. The sheer amount of stress that co-occurring disorders inflict on the brain is devastating. When left untreated, co-occurring disorders can lead to higher risks of suicide, hospitalization, violence, imprisonment, and drug overdose. Intriguingly, a large percentage of people who have co-occurring disorders are not thoroughly assessed or diagnosed properly. Often, they are only diagnosed with one of their co-occurring disorders, which can result in several difficulties with treatment.

How are co-occurring disorders treated?

Individuals who are diagnosed with co-occurring disorders should have both issues treated concurrently, or at the same time. The most recommended approach to treating co-occurring disorders is known as an integrated approach.

The goal of an integrated treatment program is to help the individual manage their mental health issues, achieve abstinence from substances, and reach their highest possible level of independence.