Understanding and Treating Dual Diagnosis: Double the Trouble

Excerpt

In this Topical Collection of Current Addiction Reports, we discuss the results of five review articles in the field of dual diagnosis—the co-morbidity of substance misuse and psychiatric disorders. This is an important clinical and academic area of investigation, which unfortunately continues to be understudied and underfunded in our fields of psychiatry and addictions. Patients who report both mental illness and substance use disorder represent ~ 8.4% of the general population, based on the recent National Survey of Drug Use and Health (NSDUH; [1]). There are many reasons for this disparity in comparison to either substance use disorders (SUDs) or psychiatric disorders alone. Studies of dual diagnosis are difficult to conduct given the clinical complexities of these populations, as well as the limited feasibility of recruiting and retaining these participants in clinical studies. Accordingly, many investigators do not invest their time in studying such “difficult” populations. This, unfortunately, has produced a substantial knowledge gap, which is very problematic since dual diagnosis represents the external reality of clinical populations in hospitals and the community. For the treatment of schizophrenia, there is evidence to suggest that antipsychotic treatment effects may be lower in real-world settings compared to RCTs, given that RCTs typically exclude patients that are more complex but representative of typical clinical presentations [2]. Similarly, patients who present with dual diagnoses have poorer treatment outcomes compared to those with single diagnoses [3] and contribute to a larger burden on the healthcare system [4]. The presence of psychiatric symptoms in those receiving SUD treatment is more likely to relapse compared to those who do not have psychiatric symptoms [5]. Therefore, research specifically into how we can best approach the management of dual diagnoses is of critical importance. Accordingly, this Topical Collection attempts to shed light on the complexities of dual diagnosis and highlights clinical assessment and treatment options available to dually diagnosed patients. …