The DSM-5 and the diagnosis of substance use disorders: Reflection about validity of the new criteria and possible ‘missing pieces’ in the puzzle

To the Editor

Given the changes in the current version of the Diagnostic and Statistical Manual of Mental Disorders–Fifth Edition (DSM-5) of the American Psychiatric Association (APA) for substance use disorders (SUDs), the unification of abuse and dependence into a single diagnostic category shows an effort to evaluate different levels of severity in the same disorder. However, little is known about the clinical implications of the diagnosis based on objective thresholds, differentiating it between mild, moderate and severe. Considering that investigations about the validity of these criteria have shown mixed support and that well-validated instruments are intended to cover the main clinical aspects regarding substance misuse, here, we investigated 72 cocaine-addicted subjects submitted to inpatient treatment using the Addiction Severity Index (ASI-6) (McLellan et al., 2006) and the Structured Clinical Interview (SCID-I) (Spitzer et al., 1992), aiming to evaluate the extent to which these instruments would be able to identify the new DSM-based criteria for SUD. In this preliminary study, the combination of ASI and SCID was insufficient to detect all the 11 symptoms of the DSM-5 especially regarding its duration and specificity. However, it is important to remember that proper diagnosis involves good clinical history, clinical examination, mental state examination, laboratory and other tests. After a more detailed evaluation, all 72 patients were classified as having ‘severe’ SUD (n = 23, 11 criteria; n = 28, 10 criteria; n = 10, 9 criteria; n = 10, 8 criteria; and n = 1, 6 criteria). Urine toxicology screening was used as an objective measure of recent cocaine use and abstinence. Our results show that patients submitted to a rehabilitation program based on the combination of chess and Motivational Interviewing (Gonçalves et al., 2014) have better treatment outcomes, but the number of DSM-5 criteria was unrelated to relapse vulnerability after a 3-month follow-up (p = 0.20). Out of the 72 patients, 45 were included in the program, and 26 remained abstinent after this period.

In conclusion, these findings reinforce the urgency for further investigations on whether the changes in the DSM-5 for SUD are associated with aspects that objectively assess the complexity of the disorder. Studies aiming to expand the capacity of instruments in assessing specific symptoms related to substance use, as well as to better investigate the validity of the new criteria for SUD are urgent. In addition, even aspects yet not contemplated by the DSM-5, such as cognitive functioning and other clinical biomarkers, should bring important and new data to better guide clinical decisions on evidence-based information.