APPLYING AN INTERNATIONAL PUBLIC HEALTH PERSPECTIVE TO PROPOSED CHANGES FOR DSM‐V

Abstract

O'Brien outlines the main changes proposed for classification of substance use disorders in DSM-V, based on an extensive consultation process and a review of the available evidence [1]. In view of DSMs wide international use, particularly for research, the proposed changes may have an impact on clinical, research and educational practices in many parts of the world. It is also important to consider potential implications of these proposals for the development of the relevant sections of the next version of the WHO's International Classification of Diseases and Related Health Problems (ICD), which remains the global standard for health information and reporting and the estimation of disease burden. The World Health Organization (WHO) is currently working on the revision of the ICD-10 [2]. The eleventh revision of the ICD (ICD-11) is scheduled for submission to the World Health Assembly for approval in 2014. Development of the ICD-11 classification of mental and behavioral disorders is being led by the WHO Department of Mental Health and Substance Abuse, and includes the revision of the diagnostic classification of mental disorders for both mental health specialists [3] and for use in primary care settings [4]. The ICD-11 development process includes consultations with Work Groups involved in the development of DSM-V [5]. Without pre-empting the conclusions of the ICD-11 development process, we offer some reflections on the proposed DSM-V changes, in order to stimulate scientific debate on these issues. From the WHO's perspective, the main purpose of the international classification is to serve as an international standard for the systematic recording, analysis, interpretation and comparison of mortality and morbidity data collected in different countries or areas and at different times [2]. In addition, the classification should have high clinical utility to facilitate effective treatment by a wide range of health professionals across specialty and primary care settings worldwide [6]. In order for ICD-11 to serve the WHO's public health mission, the classification should contain any disease or specific health condition entity that is of public health importance or that has a significant impact on individual and population health and whose accurate identification can lead to more effective utilization of health services and interventions. Globally, alcohol, tobacco, illicit drugs and other psychoactive substance use have an enormous impact on population health. According to the latest WHO estimates, alcohol use is responsible for 4.5% of total disease burden, tobacco use for 3.7% and illicit drug use for 0.9% of the global burden of disease [7]. A significant portion of alcohol- and drug-attributable disease burden is related to injuries, for example, in the case of road traffic accidents due to driving under the influence of psychoactive substances, and to other health conditions that may be caused or adversely affected by substance use in the absence of a 'substance dependence' syndrome. In spite of the obvious public health relevance of substance use in such cases, appropriate recording of the role of alcohol, tobacco and drug use continues to be a significant challenge in the practical implementation of current classification systems. From the standpoint of public health utility, this almost certainly leads to an underestimation of the true disease burden attributable to substance use and the impact of substance use and associated disorders on health care systems. From the standpoint of clinical utility, particularly in primary health care and other non-specialized health care settings, a core purpose of the classification is to provide a basis for guidance on the most effective interventions for a given diagnosis and therefore to improve access to effective treatments. This raises an important issue in relation to the DSM-V proposal described by O'Brien to eliminate the abuse/dependence distinction and to replace it with a single category of 'substance use disorder'. While there may be data to suggest that distinction represents an artificial dichotomization of a continuum or spectrum, the distinction between abuse or hazardous and harmful use and dependence syndrome has been a clinically useful one, more of less separating those with patterns of substance use behaviours that respond to brief psychological interventions from those needing more substantial treatment, including pharmacotherapy, such as detoxification and relapse prevention, or agonist maintenance treatment. The global public health importance of agonist pharmacotherapy for opioid and tobacco dependence is reflected in the inclusion of opioid and nicotine agonists in the WHO Model List of Essential Medicines [8]. How the proposed changes in classification would affect the effectiveness and safety of pharmacotherapy for substance dependence, particularly in non-specialty settings, requires further exploration. For example, what would be the