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Understanding the connections between mental health conditions and substance use disorders

Mental illness looks different on everyone.
While 37.6% of white adults with a diagnosis-based need for mental health or substance use disorder treatment received care, only 22.4% of Latinos and 25% of Black Americans did.

The stigma surrounding substance use disorders and mental health conditions has long dominated how both issues are discussed, and how those who experience these issues are seen. Because substance use disorders and mental illness frequently co-occur, meaning individuals experience both at the same time, increased stigma and stereotypical associations of one condition with the other have coloured people’s views of both.

Substance use disorders are a type of mental health condition, a disorder affecting the brain that impacts an individual’s ability to moderate their use of substances. Some of the substances commonly associated with this include alcohol, tobacco and nicotine products, opioids like heroin and oxycodone, stimulants such as methamphetamine and cocaine, and tranquilizers, including Xanax and Valium.

Though they manifest in many different ways, mental illnesses are disorders that disrupt the brain, mood, and behaviour, and impact daily life.

In 2020, 6.7% (or 17 million) of U.S. adults had both a substance use disorder and at least one other diagnosed mental illness. Those with serious mental illness, or mental illness that significantly impacted daily activities, had particularly high rates of co-occurring substance use disorder with certain substances. Misuse of opioids and tranquilizers, for instance, was roughly 6 percentage points higher among those with serious mental illness than those without a diagnosed mental illness.

Understanding why the two conditions often co-occur relates to recognizing that substance use disorder is a mental health condition, influenced by many of the same factors as other mental illnesses like depression and schizophrenia. Genetics, experiences with trauma or violence, environmental conditions, and many other factors impact how and why substance use disorders and other mental health conditions occur.

Decreasing the stigma around both conditions will, according to research, likely make receiving treatment easier.

To explore the factors that influence these conditions, Zinnia Health looked at the connection between mental illness and substance use disorder, citing early 2020 data from the Substance Abuse and Mental Health Services Administration (released in October 2021) and academic studies.

21% of U.S. adults suffer from mental health disorders

More than half of all U.S. adults will receive a mental illness diagnosis in their lifetime, according to the U.S. Centres for Disease Control and Prevention. Many mental health conditions occur together, including depression, anxiety, attention deficit hyperactivity disorder, bipolar disorder, and post-traumatic stress disorder.

Substance use disorder also commonly co-occurs alongside other mental health conditions.

Despite the common co-occurrence of substance use disorder and other mental illnesses, one condition does not always cause the other, and experiencing one condition does not always mean a person will develop the other.

Family history can influence mental health risk factors

Over the last couple of decades, scientists have increasingly come to recognize the influence of genetics on mental illness. Most research indicates that while there is no one specific gene responsible for mental health conditions, thousands of gene variants can have small impacts on mental health.

Similarly, family history and genetics account for between 40% and 60% of an individual’s susceptibility to substance use disorder.

Certain genetic factors can predispose people to dependence on certain substances. Genes can also interact to alter one’s behaviours toward risk-taking or reward-seeking, increasing or decreasing the likelihood of trying substances in the first place.

Research has also shown that similar genes are responsible for the risk of mental illness, as well as for substance use disorder, illuminating new ways of understanding the high rates of both issues occurring simultaneously.

Stress and trauma can be contributing factors for developing mental health disorders

Traumatic experiences, as well as acute stress, have been shown to have the capacity to alter the brain, particularly the amygdala, hippocampus, and prefrontal cortex (which deal with emotion, memory, and decision-making, respectively). But environmental factors like trauma and stress also have the potential to change genetic expression, bringing out some genetic material that may have previously been dormant.

The idea that environmental circumstances can trigger changes in our bodily systems, called epigenetics, also means that mental illness or substance use disorder can sometimes be brought on by traumatic or stressful situations.

Apart from the biological changes stress and trauma can inflict on the body and brain, experiencing traumatic events can cause some to self-medicate in order to deal with psychological distress. Using psychoactive substances to self-medicate can create the risk of developing future mental health conditions, as well as a substance use disorder.

Substance use can increase risk for developing other mental health conditions

Substance use can change the brain in many of the same areas altered by mental health conditions such as anxiety, depression, impulse-control disorders, and schizophrenia.

Psychoactive substances can also bring on symptoms similar to those caused by mental illness, including psychosis, paranoia, hallucinations, altered sleep patterns, mood swings, and increased risk-taking behavior. And if substance use begins before the onset of mental illness, it can increase the risk of developing a mental health condition in predisposed individuals.

There are many effective drug therapies for treating mental health conditions

Medication-based therapy has proven to be effective for many with both mental health conditions and substance use disorder.

With medical supervision, antidepressants, anti-anxiety medications, antipsychotics, and mood stabilizers, among others, can help mediate mental illness symptoms by reducing irregular brain activity, managing physical symptoms like increased heart rate, and changing how compounds like serotonin are used in the brain.

Medication-assisted therapy can also be successful in treating substance use disorder and addiction—particularly when used in conjunction with counselling and behavioral therapy. Medications like methadone can help safely prevent recovering individuals from using substances and can reduce uncomfortable or dangerous withdrawal symptoms.

Targeted behavioural therapies can also help patients with co-occurring mental health conditions

Behavioral therapies, along with medication-based treatments, can help those coping with substance use disorder and or a mental health condition. Integrated treatments, which involve treating both the substance use disorder and the mental illness simultaneously, are seen as the most effective since they acknowledge the often-intermingled causes and symptoms of the co-occurring conditions.

There are, however, many barriers that keep over half of those experiencing a mental health condition from receiving treatment. Stigma around both mental illness and substance use disorder can make seeking help feel shameful and can inspire fear and real-world consequences for wanting treatment.

Many individuals suffering from a mental health condition or a substance use disorder fear losing a job or being ostracized from their community or family. Another major barrier to receiving treatment is its often-prohibitive financial cost.

Stark disparities have emerged in who has access to quality treatment, falling along class and racial lines. While 37.6% of white adults with a diagnosis-based need for mental health or substance use disorder treatment received care, only 22.4% of Latinos and 25% of Black Americans did.

This story originally appeared on Zinnia Health and was produced and distributed in partnership with Stacker Studio.