Many people confuse the terms cross addiction and dual diagnosis. They are separate concepts:
Cross addiction is a concept that implies that if a person has developed a severe substance use disorder (the term for addiction) to one substance, that person is at a higher risk to develop a substance use disorder to some other substance.
The notion of a dual diagnosis generally refers to an individual who has two very different and unrelated psychological disorders, such as depression and an alcohol use disorder.
The notion of an increase in the vulnerability to develop another form of substance use disorder following recovering from a different substance use disorder seems to have some relevance in terms of common sense reasoning. It is also consistent with many strict disease models of addiction where individuals are unable to make rational choices regarding substance use due to changes that occur in the brain. The notion that most forms of substance use disorders share some similar brain pathways, such as the reward pathway in the brain that is primarily mediated by the neurotransmitter dopamine, would reinforce the notion of a neurobiological substrate that is responsible for a vulnerability to developing a cross addiction. However, the actual empirical evidence for the notion of cross addiction was mixed until very recently.
The notion of cross addiction is accepted as being very real in many circles; however, in other circles that point to empirical evidence, the notion of cross addiction is thought to be questionable.
Despite the relative popularity of the notion of cross addiction in many addiction treatment program descriptions, and in many 12-Step groups such as Alcoholic Anonymous, there is actually very little empirical evidence to suggest that such a phenomenon exists. This lack of research was noted by a team of researchers at Columbia University Medical Center who performed an exhaustive study on the notion of cross addiction in over 34,000 adults as part of the National Epidemiological Study on Alcohol and Related Conditions (NESARC). The findings of their study were reported in the November 2014 edition of the Journal of American Medical Association – Psychiatry. The participants in the study were surveyed in 2001 and again in 2004. There were three questions/goals of the study:
The findings have some interesting implications regarding the notion of cross addiction:
In fact, the researchers concluded that the opposite of the notion of cross addiction was more likely – that individuals who have successfully negotiated treatment for a substance use disorder were less likely to develop another substance use disorder.
The researchers at Columbia University found that the highest risk group to develop a cross addiction after successful recovery from earlier substance use disorder were unmarried males, who had a relatively early onset of their substance use disorder, and had some type of comorbid psychiatric disorder, especially disorders that were marked by impulsivity.
There are some caveats to any research study, and this particular study has a number of particular strengths and potential weaknesses. The first weakness of this study is that the study only covered a three-year period. There is no way of knowing if other individuals developed or would develop a substance use disorder at a later time. Secondly, the data was self-reported data, which can sometimes be unreliable. Researchers in future should use objective measures of substance abuse in similar studies. Nonetheless, these weaknesses do not invalidate the findings. The study is one of the few studies that looks at the actual notion of the development of a cross addiction in individuals and is able to make solid conclusions based on real data.
There appears to be very limited data to answer this question aside from clinical observations. In general, it is often considered that substances that produce similar effects can result in a higher vulnerability to cross addiction. For example, drugs that might increase the risk of developing cross addiction would include: Different drugs that have the effect of suppressing the central nervous system. These include:
Various types of stimulants including: