Managing dual disorders: a statement by the Informal Scientific Network, <scp>UN</scp> Commission on Narcotic Drugs
Authors: Nora D. Volkow, Marta Torrens, Vladimir Poznyak, Elizabeth Sáenz, Anja Busse, Wataru Kashino, Dzmitry Krupchanka, Devora Kestel, Giovanna Campello, Gilberto Gerra
Journal: World Psychiatry (2020)

Since 2015, the United Nations Office on Drugs and Crime (UNODC) – World Health Organization (WHO) Informal Scientific Network has strived to bring the voice of science as it pertains to drug use disorder treatment and care, to inform critical discussions at the Commission on Narcotic Drugs, the policy-making body of the United Nations (UN) with prime responsibility for drug control matters. In recent years, the public health dimensions of the world drug problem, including prevention and treatment of drug use disorders, have become prominent in policy debates within the UN system1. Drug use disorders can have devastating consequences for affected individuals, their families and communities. They are associated with lost productivity, security challenges, crime, and myriad negative health and social consequences. Caring for and treating individuals with drug use disorders exacts a heavy toll on the public health networks of UN Member States. Availability of effective treatments for these disorders is very limited, and far from achieving the universal health coverage target set in the Sustainable Development Goals 2030. This situation is further exacerbated by the frequent co--occur-rence of drug use disorders with other mental health conditions (dual disorders)2, a phenomenon associated with increases in emergency department admissions3 and psychiatric hospitalizations4, higher risk of relapse to drug use5, and increased likelihood of premature deaths6, including those resulting from suicide7. The individual, social and public health impact of dual disorders is very high, and a multidisciplinary and comprehensive response to the needs of persons with these disorders is required. Unfortunately, there are many gaps in the global system, which is ill prepared to meet this challenge. Lack of attention is driven in part by lack of training of clinicians on how to diagnose and treat dual disorders, as well as by the structural differentiation and lack of coordination, in many countries, between programs to treat drug use disorders and those to treat mental illnesses. Other contributing factors include "diagnostic overshadowing"8, whereby individuals suffering from a drug use disorder and a comorbid mental illness have their morbidity frequently attributed to the former, potentially neglecting the contribution from mental health (and somatic) conditions. Such neglect is partly due to the implicit bias and discrimination towards drug use disorders and the lack of familiarity of the provider with the condition that receives the attribution. Another contributing factor is the "wrong door syndrome"9, which connotes the difficulty not only for treating but also for diagnosing drug use disorders among mental and medical treatment services and vice versa. Furthermore, people with dual disorders are often excluded from studies on effectiveness of treatment interventions, which hampers the development of evidence-based recommendations for treatment of these patients. The examples highlighted above are just some of the many systemic challenges that the Informal Scientific Network considered during its recent discussions to craft evidence-based guidance for national health systems interested in developing coordinated, multiple system-level interventions to address the unmet needs of people affected by dual disorders.