A number of conditions that have been categorized as disorders of impulsivity or compulsivity may be hypothetically linked to abnormal activity of reward circuits, analogous to an addiction. To that end, there has been much interest lately in the potential symptom and neurobiological overlap between substance use disorders, impulse control disorders (ICDs), and obsessive compulsive disorder (OCD). Specifically, a great deal of debate has focused on whether disorders currently classified as ICDs should be considered “behavioral addictions” or obsessive compulsive spectrum disorders, or even whether they qualify as disorders at all. In this chapter, we review both the similarities and differences between substance use disorders and various behavioral addictions/ICDs.

This conceptualization has obvious similarities to many disorders that have been considered ICDs (e.g., pathological gambling). That is, individuals with these disorders experience tension and arousal in anticipation of performing the behavior and dysphoric mood (but no physiological withdrawal) when prevented from performing the behavior (right). In addition, the pleasure and gratification that they initially experience when performing the behavior seems to diminish over time, perhaps requiring increasing “doses” (e.g., gambling higher dollar amounts) in order to achieve the same effects (akin to tolerance).

Other common features between SUDs and ICDs include early age of onset, overlapping neurobiology (in particular, evidence of involvement of the VTA and the nucleus accumbens as well as dopamine, serotonin, glutamate, and opioids), a possible genetic relationship (supported by a small number of controlled family studies), and response to some of the same treatments (naltrexone, suggesting mu opioid involvement; N-acetylcysteine (NAC), suggesting glutamate involvement). There are also high rates of co-occurrence between various SUDs and ICDs.

As of the time of this writing, currently proposed revisions to the DSM with respect to SUDs and ICDs include:

• 1. Moving pathological gambling (renamed gambling disorder) from ICDs to “substance use and addictive disorders”

• 2. Moving pyromania, kleptomania, and intermittent explosive disorder (IED) from ICDs to “disruptive, impulse control, and conduct disorders”

• 3. Including hypersexual disorder as a “sexual disorder”

• 4. Moving trichotillomania (renamed hair pulling disorder) to “obsessive compulsive and related disorders”

• 5. Adding skin picking as a disorder in the “obsessive compulsive and related disorders” category