There were several surprising statistical pieces of information. First of all, it turns out that virtually one third (namely, 28.9%) of illicit drug users are adults diagnosed with a serious mental illness or SMI. Likewise, it turns out that almost one third of binge drinkers (namely, 28.8%) are adults diagnosed with a serious mental illness. As one can see, the numbers of binge drinkers and illicit drug users, in percentage, are almost identical. Even more surprising it was to find out that a lot fewer adults without SMI use illicit drugs (12.7%) than binge drink (23.9%). Another surprising piece of statistical data was that of SMI prevalence: statistically, at least 4 million Americans met the existing criteria for both SMI and substance abuse or substance dependence. In addition, it was interesting to find out that the fastest growing age group of people with both a substance use and mental disorder was between 35 and 45 years. It looked as if elder people (for example, those aged 65+) were more vulnerable in this regard.

As for not surprising facts, there were some as well. One example is the citation of the findings from one study that 16% of the state imprisoned, 7% of federal imprisoned, and 16% of local jail inmates either have a mental illness or have stayed in a mental hospital at least for a night. This data is not surprising given the fact that mentally ill persons are likely to engage in criminal behavior and require mental health treatment. Not surprising were the low rates of substance and illicit drug users who sought treatment within one year: 9.9% and 8.8% respectively.

With regard to the diagnostic criteria for substance use disorders, there are eleven criteria used by mental health professionals to identify and diagnose a substance use disorder. The first one is using a substance for a longer period than initially intended or taking greater amounts than initially intended. The second one is failing to reduce the use of the drug even though one wants to. The third criterion is spending too much time recovering from drug use (getting or using the drug). The fourth one is having excessively intense cravings and urges to take the substance. The fifth one is the continued use of a substance despite the problems at work and failing to deal with family, school, or other social obligations. The sixth one is the continued use of a substance despite serious problems with interpersonal relationships among family members and despite the loss of friendships.

The seventh one is giving up significant social, work, or out-of-work activities because of the continued substance use. The eighth one is the repeated use of substances, even in the situations when it is dangerous physically (e.g. using drugs or alcohol when driving an automobile or operating some machinery). The ninth one is the continued use of substance even if an individual is aware that it causes or aggravates the physical or psychological condition (e.g. continuing to smoke cigarettes in spite of having a respiratory disorder such as COPD or asthma). The tenth one is tolerance. It takes place when individuals require increased amounts of a substance to get the same desired result. In other words, tolerance occurs when an individual experiences a worse effect when taking the same amount of a substance. Under the desired result/effect one may mean the desire to get high or to avoid the symptoms of withdrawal. At the same time, drugs vary with regard to the time needed for tolerance to occur as well as people vary in their sensitivity to drugs. Finally, the eleventh criterion is withdrawal. Withdrawal is the term used to describe the body’s response to the drug’s abrupt cessation, after the individual’s body has developed a high level of tolerance of the drug. Withdrawal symptoms can be relieved by taking a greater amount of substance.

It is known that substance abuse treatment system and mental health service system have different clinical approaches, which means one can find distinctive differences between the two. The first one is the widespread use of drugs in mental health treatment, especially when there is a need to treat a severe mental health disorder. The second one is the difference between the scientific competencies of clinicians within the mental health system and substance abuse treatment. In particular, while the majority of clinicians within a mental health system are experts in a bio-psychosocial approach to identifying, diagnosing, and treating mental health disorders, they do not have sufficient knowledge of addiction treatment, patient recovery, or possible relapses. Conversely, professionals engaged in substance abuse and addiction treatment typically have a good understanding of substance abuse treatment but not mental health treatment.

One can also find similarities between the two systems. Specifically, both types of treatment are carried out in a variety of settings and employ a variety of program kinds. Next, in both treatment systems, treatment is provided by diverse professionals such as psychiatrists, psychologists, counselors, and other therapists. Further, both treatment systems rely on bio-psychological models. Treatment is provided in both private and public settings. Both types of treatment use self-help adjuncts and increasingly utilize care and case management.

In treating a client with co-occurring disorders, an integrated approach should be used. Integrated treatment unites elements of both mental health and substance abuse treatment into a comprehensive and unified treatment program for individuals with co-occurring disorders. In this way, rather than participating in two systems simultaneously or sequentially, the patient takes part in a single unified treatment program for co-occurring disorders. This approach is important because it is comprehensive, unifying, and delivering high-quality care. It involves clinicians cross-trained in substance abuse/addiction and mental health, and enables the professionals to treat patients through a variety of substance abuse and psychiatric crises.