Behavioral and Brain Sciences

Target Article

Drugs as instruments: A new framework for non-addictive psychoactive drug use

Christian P. Müllera1a2 and Gunter Schumanna1

a1 Section of Addiction Medicine, Department of Psychiatry and Psychotherapy, University of Erlangen–Nuremberg, 91054 Erlangen, Germany.

a2 MRC SGDP-Center, Institute of Psychiatry, King's College London, De Crespigny Park, London SE5 8AF, United Kingdom.


Most people who are regular consumers of psychoactive drugs are not drug addicts, nor will they ever become addicts. In neurobiological theories, non-addictive drug consumption is acknowledged only as a “necessary” prerequisite for addiction, but not as a stable and widespread behavior in its own right. This target article proposes a new neurobiological framework theory for non-addictive psychoactive drug consumption, introducing the concept of “drug instrumentalization.” Psychoactive drugs are consumed for their effects on mental states. Humans are able to learn that mental states can be changed on purpose by drugs, in order to facilitate other, non-drug-related behaviors. We discuss specific “instrumentalization goals” and outline neurobiological mechanisms of how major classes of psychoactive drugs change mental states and serve non-drug-related behaviors. We argue that drug instrumentalization behavior may provide a functional adaptation to modern environments based on a historical selection for learning mechanisms that allow the dynamic modification of consummatory behavior. It is assumed that in order to effectively instrumentalize psychoactive drugs, the establishment of and retrieval from a drug memory is required. Here, we propose a new classification of different drug memory subtypes and discuss how they interact during drug instrumentalization learning and retrieval. Understanding the everyday utility and the learning mechanisms of non-addictive psychotropic drug use may help to prevent abuse and the transition to drug addiction in the future.

Christian P. Müller is professor of Addiction Medicine at the Friedrich-Alexander-University of Erlangen-Nuremberg, Germany. Dr. Müller studied Psychology at the Universities of Düsseldorf and Oxford. He received his Ph.D. in Experimental Psychology at Düsseldorf. He was a senior lecturer at the Institute of Psychiatry, King's College London (UK). Dr. Müller has published on the neuropharmacology and neurochemistry of addictive drugs as well as on anxiety and sensorimotor activation. His major focus of research is the role of the serotonergic system in behaviour. He is editor (with B. L. Jacobs) of the Handbook of the Behavioral Neurobiology of Serotonin (Academic Press, 2010).

Professor Gunter Schumann studied medicine at Tübingen, Hamburg, and Boston. After a postdoctoral fellowship at the Dana Farber Cancer Research Institute, Harvard Medical School, he trained as a psychiatrist at the Universities of Freiburg and Heidelberg. From 2000–2005 he was a consultant psychiatrist and head of the Molecular Genetics Laboratory at the Central Institute of Mental Health in Mannheim, Germany. Since 2005, he has held a chair in Addiction Biology at the Institute of Psychiatry, King's College, London, and is an honorary consultant at South London and Maudsley NHS Trust. He is the coordinator of an FP6 European research project IMAGEN, deputy director of the National Institute for Health Research (NIHR)-Biomedical Research Centre (BRC) in Mental Health and theme lead for Substance Use Disorders.