There are a number of important factors that we know can contribute to a person developing an addiction. For instance, we know that things like one’s environment, one’s social circumstances and simply one’s physical access to drugs can be hugely influential in whether or not a person becomes addicted. However, we still know very little about what biological factors might predispose a person to becoming addicted, which is why much addiction research focuses on causality.
Since addiction is, in many ways, as much a mental disorder as it is a brain disease, researchers have been trying to identify ways that the two could be related. In particular, do psychiatric disorders cause addiction or vice versa?
This is a very prominent question in today’s addiction research, but there’s very little explanation why this is such an important question to answer. Therefore, let’s take a moment to look at what the potential relationship between psychiatric disorders and addiction might be and why it’s so important.
What Do We Know About Psychiatric Disorders and Addiction?
Time and again, studies have found that there are high levels of correlation between mental and emotional disorders and addiction. This means that those who suffer from addiction have a higher-than-average likelihood of also suffering from a psychiatric disorder. Currently, it’s estimated that about one in five American adults suffer from some type of mental illness.1 Meanwhile, those who are diagnosed with a mental illness at some point in their lives are estimated to account for 69 percent of all alcohol, 84 percent of all cocaine and 68 percent of all cigarettes consumed.2
Most researchers agree that one of three possible scenarios is happening in each instance of these co-occurring disorders. First, it’s possible that drug abuse can cause symptoms of one or more mental disorders. Second, it’s possible that individuals suffering from certain mental disorders can develop substance abuse problems since substance abuse can be a symptom of a number of different mental disorders. Finally, it’s possible that the development of addiction and many psychiatric disorders involve similar areas of the brain or risk factors.3
New Study Reinforces Link Between Mental Illness and Opioid Use
There have been a variety of effects attributed to long-term opioid abuse, including self-injury, vehicular accidents, depression,4 anxiety and suicide. However, researchers from Indiana University have actually found that the reverse can be true, too. In other words, the study shows that individuals who exhibit such symptoms as depression, suicide attempts and self-injury as part of mental or emotional disorders have an increased likelihood of developing long-term opioid use problems.
We’ve known that individuals who are prescribed opioids for an amount of time are at risk of becoming dependent on those drugs. However, not only is the same true for individuals who suffer from psychiatric disorders, but these individuals also exhibit an increase in their likelihood of long-term opioid use.5 According to these statistics, about 1.7 percent of all individuals who are prescribed opioid drugs become dependent. However, attention deficit and similar disorders were associated with a 1.5-times increase in an individual’s likelihood of long-term opioid use. Other disorders were associated with a threefold increase in likelihood with the highest risk — a ninefold increase — being among those individuals who have histories of opioid abuse in the past.
What Does This Relationship Tell Us?
There’s strong evidence of a relationship between psychiatric disorders and addiction. However, a relationship does not equate to causality.6 As well, this relationship isn’t the same between addiction and every psychiatric disorder or for every individual. What research shows is that the relationship is complex, suggesting many possible points of overlap between addiction and psychiatric disorders. The fact that there’s a relationship tells us that there is likely a number of shared risk factors between addiction and certain mental illnesses. In other words, many of the main risk factors for addiction — i.e., environment, social group, genetics — are also risk factors of certain psychiatric disorders. As well, we know that depression, bipolar disorder, anxiety and schizophrenia affect many of the same areas of the brain that are affected by addiction.7
Individuals with mental health disorders may be less inhibited than the average person, making them more likely to experiment with substance abuse and leaving themselves vulnerable to the development of addictions. Alternately, addicts’ long-term abuse of alcohol and drugs can result in the manifestation or exacerbation of psychological distress. It’s also possible that a number of environmental or experiential factors — i.e., the experience of trauma during adolescence — can result in post-traumatic stress or substance abuse problems in adulthood, showing the similarities in risk factors of addiction and mental illness.
Clearly, there’s no easy way to answer the question of what kind of relationship psychiatric disorders and addiction have. However, the reality and implications of the relationship are quite clear. In the meantime, we should continue to research this subject because learning more about how addiction and mental disorders intersect will lead to better addiction prevention methods, diagnosis and addiction treatment.
Written by Dane O’Leary