Addictions are an acute problem in the 21st century. According to the Centers for Disease Control of the U.S., 8.9% of individuals surveyed in 2010 indicated they had engaged in illicit drug abuse during the previous month. The World Health Organization (WHO) reported 15.5 – 38.6 million people worldwide had problems with drug use in 2010. Drug, alcohol, and tobacco problems are examples of substance addictions. By definition, a substance addiction interferes with the person’s life in some way. For example, if a person with emphysema continues to smoke, he or she is addicted to tobacco. A less dramatic example is the alcohol user who has blackouts, loss of memory, and a trail of ruined relationships. Individuals with substance addictions experience withdrawal symptoms when they discontinue use of their drugs of choice (Capuzzi & Stauffer, 2012).

Another type of addiction is process addiction. This term refers to the compulsion to repeat certain behaviors which, when carried to excess, have the potential to interfere with a person’s daily functioning (Zhang et al., 2012). Process addictions include gambling, sex, Internet, shopping, and similar behavioral addictions (Capuzzi & Stauffer, 2012). The recently published Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM–V; American Psychiatric Association, 2013) officially cites only gambling as a type of process addiction; however, other possibilities, such as sex addiction and Internet addiction, are mentioned in the DSM-5 appendix as requiring further study.

Grant et al. (2010) state that the common foundation of both substance and process addictions is diminished control. However, diminished control is seen in both addictions (such as alcohol abuse) and in impulse control disorders (such as intermittent explosive disorder). The previous version of the Diagnostic and Statistical Manual, DSM-IV-TR, classified problems such as compulsive gambling under the heading of impulse control disorders; there was no specific category of behavioral addictions (American Psychiatric Association – APA, 2000). The DSM-V created the new category of behavioral addictions, which included gambling. Other potential types, such as sex addiction and Internet addiction, are currently listed in the DSM-V appendix as requiring further research before they can be categorized as either addictions or impulse control disorders (DSM-IV-TR, 2000; DSM-V, 2013).

In addition to diminished control, there are several other similarities between substance and process addictions. Both a) frequently begin in adolescence or young adulthood, b) result in emotional disturbance if the substance or behavior is avoided, c) cause cravings for greater amounts of the addicting substance or behavior, and d) induce the addicted person to steal or do other illegal things to pay for the addiction or the consequences (e.g. gambling losses) (Zhang et al., 2012). Although the neurobiological literature on addictions is limited, it appears that substance and process addictions involve a variety of neurotransmitters, such as dopamine, serotonin, and norepinephrine (Grant et al., 2006). Substance and process addictions frequently occur together; mood disorders are also common, which has led to the name “dual diagnosis” used in many substance abuse treatment programs.

One of the reasons that separating substance from process addictions is difficult is the number of similarities between them, particularly in the emotional changes that take place in the use-emotional disturbance-craving-use again cycle. It may not be obvious to the clinician, initially, that there are similar symptoms that may be caused by different issues. Another difficulty is the frequent co-occurrence of the two addiction types. Unless clinicians are specifically trained to recognize process addictions, they may fail to note them, especially since substance abuse often produces physical changes that do not apply in most or all process addictions (e.g. increased heart rate and blood pressure, pupil size). However, if a clinician begins by treating an obvious substance addiction successfully, process addictions often become stronger. At that point, the process addiction and any co-occurring disorders can be treated. Also, according to Potenza et al. (2011) and others, the neurobiological basis of addiction can be treated, usually by pharmacological methods, even without specifying the addiction.

Although substance and process addictions are different in that one is chemical and the other is behavioral, there are more similarities than differences between them. Determining whether a person has a substance or a process addiction can be difficult. However, since the underlying foundation is often the same, sometimes similar treatments can be used, even if a mistake is made in diagnosing the exact addiction.