Not very long ago, addiction was considered a moral affliction. Addicts were seen as bad people, willfully selfish and hedonistic, rather than individuals suffering from a mental and physical affliction. After years of research, we now have a more enlightened understanding of addiction with the current model revealing that addiction is a chronic, progressive disease of the brain. In fact, addiction is sometimes alternately referred to as a substance use disorder, which prompts comparisons to conditions like Alzheimer’s disease or dementia as frequently as illnesses like diabetes.
Recent studies concerning the nature of addiction have identified high instances of co-occurring mental illnesses among individuals who suffer from substance use disorders. This has led many to question whether there’s some sort of relationship—perhaps even causation—between addiction and a secondary diagnosis in an individual. In other words, in individuals who suffer from both an addiction and an additional diagnosis, did one disease cause the other?
By definition, the term “co-occurring disorders” is used to refer to the instance of two diagnoses occurring in a single individual. As far back as the 1980s, research has continued to indicate that the disease of addiction has a high rate of co-occurring with other mental illnesses, with individuals who suffer from addiction being about twice as likely to also suffer from a mental illness when compared to the overall population. Likewise, those with mental illnesses are about twice as likely to become dependent on chemical substances. Addiction itself could be considered a mental illness, but the concurrent physical nature of addiction prevents it from being classified merely as a mental health disorder; however, since part of the disease is psychological, individuals who develop addictions will exhibit certain psychological symptoms in addition to physical, chemical dependence.
In terms of psychological symptoms, individuals who have developed addictions have a dramatically disrupted hierarchy of needs, suggested by their tendency to act against their own self-interests. This is illustrated by the habitual substance abuse behavior in spite of the numerous consequences, including a decline in overall physical health and potential legal repercussions. As such, addicts become incapable of controlling their impulses, which is also a symptom of many other mental illnesses. It’s also important to note that substance abuse directly affects levels of neurochemicals like dopamine and serotonin in the brain, which control one’s mood among other things. Similarly, mood disorders typically cause an imbalance in these chemicals and often require a medication like an antidepressant to correct the imbalance. Clearly, there’s much overlap between the disease of addiction and mental illness.
The rate of co-occurring mental illness is higher among individuals who suffer from drug addiction than those who suffer from alcoholism at an estimated 72 percent and 45 percent, respectively. Depressive disorders are a common occurrence among those with a substance use disorder, but the data is sparse and variable. In individuals who suffer from alcoholism, up to 67 percent are also diagnosed with a depressive disorder while up to 75 percent of those who are opioid-dependent receive a similar diagnosis. According to reports from treatment providers, between 20 and 45 percent of those in recovery for addiction are diagnosed with co-occurring post-traumatic stress disorder (PTSD), lending further credence to the theory that traumatic experiences significantly increase one’s likelihood of abusing alcohol or drugs. Between 10 and 15 percent of individuals in treatment meet the diagnostic criteria for social phobia, but reports indicate that they rarely receive an actual diagnosis while in treatment. With such astonishingly high rates of co-occurring disorders among addicts, researchers have come up with a few theories as to how addiction and mental illnesses might be related.
First, it’s suggested that the development of alcohol or drug addiction may trigger symptoms of a mental health disorder, which is evidenced by the increased risk for psychosis among users of marijuana. The second idea is that mental illness may trigger substance abuse and develop into an addiction, which is illustrated by the tendency of victims of trauma or violent crimes to turn to substance abuse as a means of coping. The final idea is the notion that addiction and a co-occurring mental illness have shared or overlapping risk factors, which can include genetic or biological anomalies, environmental triggers like stress or trauma, involvement of similar areas of the brain, or some factor relating to adolescent development. In actuality, it’s most likely that instances of co-occurring mental illness and addiction occur due to some interplay of all three possibilities. This is even more likely considering the strong psychological basis for addiction and the symptoms that addiction shares with mental illnesses. In short, addiction may cause mental illness, be caused by mental illness, or develop simultaneously and independently due to overlapping risk factors.
The brain is an enigma. Despite the mounting and continuous research, our understanding of the human mind is tentative and tenuous. However, we continue to develop a more thorough understanding of the most complex organ in any organism on the entire planet. It’s important to be knowledgeable on afflictions like substance use disorder and its relationship to mental illnesses. This can afford the ability to help those who suffer from such conditions find quality treatment for their symptoms and achieve better quality of life. If you or someone you know would benefit from learning more about addiction or the complicated relationship between addiction and co-occurring mental illness, contact us anytime—day or night—and one of our admissions coordinators can help you or your loved one begin the healing journey.
Written By Dane O’Leary
Integrated Treatment of Substance Abuse & Mental Illness