Delusional Disorder & Substance Abuse: Causes, Symptoms & Treatment

4 min read · 6 sections

Delusional disorder is a mental health condition that is thought to have a lifetime prevalence in the general population of around 0.2 percent, according to the Journal of the American Academy of Psychiatry and the Law; however, this number may not represent the total amount of people who suffer from this disorder, as it may often go undetected.

People suffering from delusional disorder may function normally in society for the most part. Delusional disorder, as defined by Psych Central, is the presence of untrue beliefs that are either bizarre or non-bizarre in nature that persist for at least a month. Bizarre delusions are beliefs or situations that are likely not plausible, while non-bizarre ones may seem that they could even be realistic, which may be how this disorder can go without diagnosis.

Delusional disorder may be considered a subtype of a psychotic disorder. Delusional disorder differs from schizophrenia, of which delusions are also a sign, in that the delusions do not typically interfere with normal or psychosocial functioning abilities. The disorder may manifest from a paranoid personality disorder first, the Merck Manual reports. In order for a diagnosis of delusional disorder to be made, schizophrenic symptoms are not present; delusions are not the result of substance abuse or a mood disorder; and behaviors and life functioning are not significantly impaired.

Symptoms of Delusional Disorder

According to the Merck Manual, delusional disorder generally presents itself in middle to late adulthood. It may begin with individuals becoming seemingly obsessed with things, like the loyalty of friends and family members, or a general distrust of people. Suspicion, belief that they are being exploited, perceiving threats where they may not actually exist, reading more into a situation than is necessary, and quick reaction to anything that might be construed as a slight are common warning signs for delusional disorder.

Many times, the delusions a person suffers from seem perfectly logical, as they may be things that could actually happen in real life. Examples include the idea that a lover is cheating, that the boss is conspiring to fire the individual, that a friend may secretly work for the government, etc. These are called non-bizarre delusions. Prior to the publication of the newest Diagnostic and Statistical Manual of Mental Disorders, the DSM-5, in order for a diagnosis of delusional disorder to be made, the delusions had to be non-bizarre in nature. The DSM-5, in contrast to the DSM-IV and previous versions, includes bizarre delusions as well as non-bizarre ones. Bizarre delusions may be more “out there” and less plausible, such as the belief that someone switched out one’s internal organs or that one has insects crawling under their skin.

These delusions do not significantly interfere with a person’s life, however, and the individual may not seem to have an issue unless the delusional beliefs are stirred up. Mood disturbances may accompany delusions; however, they are typically short-lived. Anger, paranoia, violence, and irritability may be side effects of suffering from delusions and may therefore occur as the result of delusional disorder. Social isolation, relationship issues, legal battles, an unwillingness to accept necessary medical care, and troubles at work or school may be consequences of untreated delusional disorder, as these difficulties may be the result of persisting delusions as well.

People suffering from delusional disorder may, on some level, understand that their delusions are untrue, but be unable to shake them. Delusions can progress over time, and proper treatment can help individuals to learn how to manage these delusions as they arise and keep them from interfering with everyday living.

What Causes Delusional Disorder?

There is not a specific known cause for why one person may develop delusional disorder and another may not, although researchers have several theories involving genetics and a possible underlying predisposition to the disorder. Delusional disorder is related to schizophrenia, a serious mental illness involving psychosis and the significant impairment of daily life, and the Canadian Journal of Psychiatry explores a potential genetic link between the two disorders. Genes that are involved in the onset of schizophrenia may play a role in the development of delusional disorder. If a close family member battles schizophrenia, therefore, it may be more likely for an individual to suffer from delusional disorder. Other biological factors may be related to the onset of delusional disorder as well, News-Medical reports. An imbalance of brain chemistry or an injury to the frontal lobe may contribute to its onset, as may hearing or vision issues.

Someone who is already predisposed to thoughts that may be delusional in nature and then suffers from mitigating environmental factors may be more likely to suffer from delusional disorder as well. In this manner, environmental factors may also play a role in the onset of the disorder, per Psychology Today. High levels of stress due to loss of a job, medical treatments, or legal troubles may therefore increase the odds that a person will suffer from delusional disorder. It may often be the combination of biological, genetic, and environmental factors that together all contribute to why a person may battle delusional disorder.

Co-Occurring Delusional Disorders & Substance Abuse

Many different mind-altering substances may cause a person to suffer from delusions; however, for a diagnosis of delusional disorder, the delusions must not be the result of substance abuse. Someone suffering from delusional disorder may turn to drugs or alcohol in order to try and self-medicate the symptoms, however, which may actually serve to make them worse instead. Some substances, like alcohol, opioids (heroin and prescription pain killers), and benzodiazepine medications (sleep aids and anti-anxiety drugs), may seem to dampen the symptoms of delusional disorder temporarily, as these substances slow down functions of the central nervous system, like blood pressure, heart rate, and respiration levels.

These substances alter brain chemistry to do so, however, and repeated use makes changes in the way the brain functions, potentially leading to drug dependence and addiction. This may be particularly problematic when someone also suffers from a concurrent, or co-occurring, mental health disorder such as delusional disorder. The Substance Abuse and Mental Health Services Administration (SAMHSA) reports that almost 8 million Americans (aged 18 and older) battle co-occurring mental health and substance abuse disorders. Co-occurring disorders may be best served through specialized treatment programs that involve an integrated treatment method in order to work through some of the complications that may arise as the result of the two different disorders. Substance abuse may increase the magnitude of a person’s delusions and potentially lead to an exaggerated response (e.g., heightened aggression, self-harm, or more risky behaviors). Delusions may become more profound as the result of substance abuse therefore, and treatment may need to be tailored to address this.

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When and How to Get Help

Delusional disorder may be regularly overlooked and undiagnosed. Substance abuse may be the result of undiagnosed and untreated mental illness, and can lead to further issues surrounding drugs, alcohol, and addiction. Family members and loved ones are often some of the best resources for knowing when a problem may exist. Denial swirls around both addiction and delusional disorder, and the individual at risk may not wish to recognize that a problem exists.

Nonconfrontational, nonjudgmental, and positive support methods are vital in getting help for a loved one. Families and friends may wish to talk to a professional interventionist in order to develop a plan for a constructive conversation with the affected individual.

An intervention is a planned and structured meeting of people in a person’s social and familial circle, and may include coworkers, neighbors, church members, teammates, classmates, family members, and anyone else impacted by an individual’s substance abuse and/or mental illness. The main goal of an intervention is to get the person to seek out help, and a professional interventionist can assist with this process. A family doctor, mental health professional, or substance abuse treatment providers may be able to help with an intervention, or families may choose to find and use a professional interventionist who is a member of the Association of Intervention Specialists (AIS), follows a specific code of ethics, and is trained in helping families through a potentially difficult conversation as smoothly as possible.

In Conclusion

Delusional disorder is not commonly diagnosed, and therefore considered rare, although it is entirely possible that due to an individual’s high level of functioning in daily life, aside from their non-bizarre or bizarre delusions, the disorder often goes undiagnosed and therefore untreated. Substance abuse may be a method of self-medication for delusional disorder symptoms that may progress over time and ultimately results in worsening side effects as well as issues with drug or alcohol abuse, dependence and/or addiction. With a strong therapeutic alliance, individuals may learn how to manage and minimize delusions. An integrated treatment model can also reduce issues related to substance abuse and enhance long-term recovery with an improved quality of life.

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