How Substance Abuse Affects Mental Health

Dr. Ximena Sanchez-Samper

Ximena Sanchez-Samper, MD is a Board- Certified Addiction Psychiatrist who obtained her degree as a psychiatrist at the Mayo Clinic in Rochester, MN and completed her Addictions Fellowship through the combined Massachusetts General Hospital, McLean Hospital / Brigham and Women’s Hospital Addictions Fellowship program in 2004.

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Understanding How Substance Abuse Affects Mental Health

Mental health is a person’s emotional, physiological and social well-being. It influences how individuals think, feel and behave in daily life. Several factors can change a person’s mental health. For instance, facing high demands without enough resources and support to accomplish a task can lead to mental illness. Substance abuse is another contributing factor to this problem. Let’s explore how abusing different substances affect mental health, the signs that they can show and possible treatment methods.

Effects of Different Substances on Mental Health

Various categories of substances are used for recreational purposes. These can be categorized according to how they affect the user’s body. They can result in long-term mental health issues.


These drugs can slow the function of the central nervous system. They affect the relaying of messages between the brain and the body, resulting in reduced concentration and coordination. They also interfere with a person’s ability to respond to the activities around them. Depressants include alcohol, cannabis, ketamine and benzodiazepines.

Prolonged use of depressants, especially alcohol and benzodiazepines, can lead to symptoms of depression and anxiety. Initially, these substances can provide relief from stress or anxiety. However, intense use can disrupt neurotransmitter balance in the brain. This leads to dysregulation of mood and worsening of underlying mental health conditions.

Depressants can also impair cognitive function, including memory, concentration and decision-making abilities. For instance, chronic alcohol use can lead to cognitive deficits and difficulties with learning and information processing. Benzodiazepines, on the other hand, can cause cognitive impairment, especially in older adults.

In some cases, prolonged use of depressants can induce psychosis. Symptoms may include hallucinations, delusions, paranoia and disorganized thinking. Alcohol-induced psychosis can occur during acute intoxication or withdrawal.

While these drugs are used to induce sleep, overreliance can result in disruption of normal sleep patterns. A person with substance use disorder (SUD) can suffer from insomnia. Without quality sleep, the individual may have poor mental health. This is because a person with insomnia is 10 times more likely to develop depression. They are also 17 times more at risk of developing anxiety than those who get good sleep.


These are drugs that change a person’s sense of reality by causing hallucinations. Drugs such as phencyclidine, cannabis and psilocybin “magic” mushrooms distort the five senses. When taken in small doses, hallucinogens give a feeling of floating, numbness, confusion, disorientation or dizziness. 

Any hallucinogen can cause mental issues or worsen existing problems. This can happen during hallucinations, which are primarily visual but can also be auditory, tactile or olfactory. The events in hallucinations are unpredictable and, sometimes, can be frightening. For some, there may be recurrent flashbacks even after the initial short-term effects have ended. This is known as hallucinogen persisting perception disorder (HPPD), which can occur weeks, months or years after complete cessation of substance use. While this does not happen to every user, a small portion of users experience at least one flashback. HPPD flashbacks and visual distortions can be distressing, leading to functional impairment or anxiety. 

Hallucinogens also disrupt normal thought processes, leading to disorganized thinking and loosening of associations. Individuals may experience a distorted sense of time, space and self. This makes it challenging to maintain a coherent understanding of reality. There may also be heightened emotional states and rapid mood changes. Some people experience euphoria, while others have intense anxiety, panic or dysphoria. These fluctuations of mood can contribute to a sense of vulnerability and psychological distress. 


These substances speed up the relaying of messages between the brain and body. Consequently, the user has increased alertness, energy and attention. Stimulants include caffeine, cocaine, nicotine and ecstasy. Sometimes, medical practitioners use stimulants such as methylphenidate for therapeutic purposes. This includes treatment of attention deficit hyperactivity disorder (ADHD) in children and narcolepsy. A 2016 study found that about 16 million adults had used a stimulant during the previous year on the recommendation of a medical professional. About 31.2% of these misused their medications without use disorders, while 2.5% developed stimulant use disorder. 

Substance abuse or misuse can affect an individual’s mental health by affecting mood regulation. This causes feelings of depression, anxiety and paranoia, particularly during the withdrawal phase. As the effects of the drug wear off, individuals may experience a crash. This is characterized by dysphoria, irritability and emotional instability. These effects occur because of chemical changes caused by the drug. There may be increased dopamine and norepinephrine levels in the brain, which disrupt neurotransmitter balance. Chronic stimulant use can also lead to downregulation of dopamine receptors, worsening feelings of depression and anxiety over time.

The heightened state of arousal produced by stimulants can contribute to feelings of paranoia. This is characterized by irrational fears, suspiciousness and hypervigilance. Individuals may perceive threats or dangers that are not present in reality, leading to social withdrawal and isolation.

Stimulant drugs, especially cocaine, can make pre-existing mental health conditions more severe or trigger the recurrence of previous problems. Individuals with a history of depression, anxiety or psychotic disorders may be vulnerable to the harmful effects of stimulant use. Those with a history of psychosis or schizophrenia may experience worsening symptoms or the onset of acute psychotic episodes after using a stimulant.

Ecstasy (MDMA) is a synthetic stimulant with hallucinogenic properties commonly used for its euphoric effects and enhancement of social interactions. However, its use is associated with cognitive impairments. Chronic use can lead to deficits in verbal and visual memory. These memory problems can persist even after someone stops using ecstasy. They may have long-term implications for academic, occupational and social functioning.

Factors Contributing to Mental Illness and Substance Use

Substance use is much more prevalent among people with mental health issues. Among U.S. adults in 2019, the rate of tobacco smoking was 1.8 times higher for those with mental illness in the previous year.

Up to 85% of people with schizophrenia and 70% of people with bipolar disorder smoke. The comorbidity between mental illness and substance use disorder does not mean that one necessarily causes the other. Various factors can cause mental illness and substance use disorder to develop in the same person.


Emotional or physical trauma can make a person vulnerable to substance use, resulting in dependence. For instance, a client who suffers from post-traumatic stress disorder (PTSD) can use substances to reduce anxiety. More than 20% of veterans with PTSD also have SUD, and almost a third of veterans seeking help for SUD also have PTSD.

Personality Traits

Some personality traits influence how people cope with stressors in their lives. Those who lack effective coping strategies may have developmental issues. They can also end up using substances to manage their situation. Traits such as low self-esteem, high levels of neuroticism (emotional instability) or perfectionism can create vulnerabilities to mental health issues. For instance, individuals with perfectionistic tendencies may experience heightened stress and anxiety. This increases their risk of conditions like obsessive-compulsive disorder or depression. 

Some people have personality disorders, which are, by themselves, mental health issues. These include borderline or antisocial personality disorders. When trying to manage the trait, a person can resort to drug use. Such a person is also vulnerable to other mental health issues. 

Genetic Influences

Genetics accounts for 40%–60% of an individual’s vulnerability to SUDs. This happens when a gene product influences how the body responds to a substance and how long it will remain in the bloodstream.  Genes may also alter the body’s response to stress. A stressed person may take dangerous risks or engage in novelty-seeking behaviors, including substance use. This can lead to mental disorders or developmental issues. 

Childhood Environment

Childhood experiences of abuse, neglect or other forms of trauma can increase the risk of both SUD and mental health disorders later in life. Traumatic experiences can disrupt healthy development, leading to difficulties in emotional regulation, coping mechanisms and interpersonal relationships. 

Childhood environments also include interactions with peers. Peer influence can significantly shape behaviors related to substance use and mental health. Children who associate with friends engaging in risky behaviors, such as substance use or delinquency, may be more likely to adopt similar behaviors. This can lead to more risk of SUD and mental health problems.

Treatment for Substance Use and Co-Occurring Mental Disorders

Clients suffering from both mental and substance use disorders will receive treatment for both conditions at the same time. Treatment options should be tailored to the person’s symptoms. Here are some effective treatment options.

Behavioral Therapy

Behavioral therapy can be used alone or when combined with medical treatment to manage co-occurring SUD and mental problems. The medical caregiver can choose cognitive behavioral therapy (CBT). This is a therapeutic approach that focuses on identifying and modifying irrational thought patterns and behaviors. CBT helps clients recognize and challenge the distorted beliefs and negative thought patterns that contribute to substance use and mental health symptoms. It also teaches coping skills to manage cravings, stress and triggers for substance use.

Alternatively, they may choose dialectical behavior therapy (DBT). This incorporates mindfulness skills and techniques to regulate emotions, improve interpersonal relationships and tolerate distress. DBT is effective for individuals with co-occurring substance use and borderline personality disorder or other emotion dysregulation issues. 

Additional therapies, such as assertive community treatment, therapeutic communities, and contingency management, are available. 


Medication-assisted treatment involves using medications alongside counseling and behavioral therapies. Specific medications are used to alleviate withdrawal symptoms and reduce cravings. They can also stabilize moods in individuals with co-occurring mental health issues.

Dual Diagnosis

Dual diagnosis or co-occurring disorder treatment addresses SUD and mental health issues simultaneously. This approach recognizes the relationship between substance use and mental health. It aims to provide care according to the individual’s needs. This treatment option is commonly applied to clients with severe mental health problems and substance misuse.

Support Groups

About 40%–60% of addicts are likely to relapse. That’s why it is crucial for recovering clients to join a support group. Here, they can receive peer support, encouragement and accountability from other individuals recovering from SUDs. Many support groups also offer specific meetings for individuals with co-occurring mental health issues. The person can also learn and adopt healthy lifestyle changes, such as adequate sleep, regular exercise, a nutritious diet and stress management techniques. These can support overall well-being and aid in recovery from both disorders.

Finding Treatment

If you or a loved one is suffering from SUD as well as mental health problems, you need to seek professional help. Researching different treatment options and providers is essential to finding the most suitable fit. Consider factors such as the type of treatment offered and the approach to treatment.  

At Charles River Recovery, we aim to provide our clients with the highest-quality treatment methods. We focus on their emotional, physical and spiritual needs and provide care and support for their recovery. Our licensed team offers individual treatment to each client, whether they suffer from alcohol, cocaine, meth, prescription pill or opioid use disorder.

Contact Charles River Recovery today to begin your recovery journey.