The Prevalence of Co-Occurring Disorders
Individuals with substance abuse disorders as defined by the DSM-V can present with symptoms of many other mental health disorders. It can be difficult to separate the symptoms of these two categories of illness without treatment to determine what the precipitating event was. In some instances, the existence of a mental health disorder can be the cause and the substance abuse disorder can be one of the symptoms that has progressed to the point of meeting diagnostic criteria on its own. In other instances, the substance abuse disorder can be creating symptoms of mental health disorders that would not otherwise be present. A third possibility is that the mental health disorder began after the substance abuse disorder developed but, either through permanent neurological damage or stressors created during the use a new mental health disorder has been created that will be alleviated upon cessation of drug use.
For these reasons it may be difficult to come up with very accurate statistics for the existence of co-occurring disorders. (Talboy 2008)The number of facilities treating co-occurring disorders has increased between 1997 and 2002 but this has only represented and increase from 44.7 to 49 percent. This is a surprising figure when compared to some of the indicators of the prevalence of co-occurring mental health disorders in the substance abuse population. This however is in line with the reported increase in reported co-occurring disorders. According to a voluntary survey conducted by state alcohol and drug abuse agencies, it appears there was a 10% increase in the prevalence of co-occurring disorders.
The rate of Co-Occuring disorders changes depending on the kinds of drugs used as well as the combinations of drugs used. As an example, when cocaine is used, the rate of antisocial disorder is 30.4%. This rate increases to 47% when cocaine is combined with alcohol. If heroin is added to this combination the rate jumps to 59.8%. This is not a surpassing statistic but what it does not explain is if the mental health symptoms are present because of the substance abuse disorder or if the mental health symptoms were a precipitating factor in causing the substance abuse disorder.
The surprising nature of these statistics was the substance abuse disorders with low rates of co-occurring disorders. Of those addicted to heroin, the rate of generalized anxiety disorder is only 2%, but that rate does increase to 3.2% when combined with alcohol abuse and again increase to 6.3% when combined with alcohol and cocaine.
The common thread between these mental health disorders that co-occur with substance abuse disorders is that there is an increase in their prevalence when there are multiple drugs used. In particular when alcohol is included there is a marked increase in mental health diagnosis. It seems to be self-evident that people do not become addicted to substances without first having a reason to use. As an extension of this, it would seem obvious that the majority of those who decide to use drugs are not generally people who are happy and free of mental health symptoms. It is surprising that these co-occurring disorders are not far more common or even universal among substance abuse clients. This may explain why the number of substance abuse clinics offering mental health treatment in addition to substance abuse treatment is still barely over half as of the year 2000.
The Differences and Similarities in the Mental Health and Substance Abuse Systems
One of the reasons that substance abuse and mental health disorders share a great deal in common is that substance abuse disorders are, in fact, mental health disorders. (Comorbidity addiction and other mental illnesses, 2010) For this reason, substance abuse is divided into two separate categories by the DSM, which are dependence and abuse. Mental health issues are likely to lead to one or the other. They can also be caused by the same issue. There is some information indicating that both mental health disorders in general and substance abuse disorders in particular may be caused by the same genetic predispositions.
Another linking factor between mental health and substance abuse is the brain regions affected. It has been shown that substance abuse and other mental health disorders impact the same regions of the brain. Neuro-chemicals impacted by substance abuse, it appears, are the same chemicals impacted by depression, schizophrenia, and other psychiatric disorders. There is a class of anti-depressant drugs that target dopamine, which is a chemical in the brain related to pleasure, movement, motivation and emotion. This is one of the primary chemicals to be increased through any pleasurable action including the use of drugs.
This connection common chemical may lead to those with mental health disorders self-medicating to alleviate symptoms through the use of illicit drugs. The effect of substance abuse, other mental health disorders as well as mental health medications all impacting the same regions and chemicals of the brain can cause people to believe that abusing drugs is effectively treating mental health symptoms.
Comorbidity addiction and other mental illnesses. (Rev. Sept. 2010 ed.). (2010). Rockville, MD: U.S. Dept. of Health and Human Services, National Institutes of Health, National Institute on Drug Abuse.
Talboy, E. (2008). Substance abuse treatment for persons with co-occurring disorders inservice training: based on a Treatment Improvement Protocol, TIP 42. Rockville, MD: U.S. Dept. of Health and Human Services,Substance Abuse and Mental Health Services Administration, Center for Substance Abuse Treatment.