Drug dependence as a split object: Trajectories of neuroscientification and behavioralization at the Max Planck Institute of Psychiatry.

Today, drug dependence is often understood as a "brain disease" and as an indication for behavioral therapy. In this article, I trace the historical development of the notions of drug dependence as a neuronal and behavioral problem in the local research context of the Max Planck Institute of Psychiatry in Munich, Germany. Focusing on the period from the 1950s to the 1980s, I argue that the neuroscientific and behaviorist understanding of "dependence" had two different trajectories that were yoked together under the same institution of self-proclaimed basic research: (a) the neuroscientific notion derived from an older toxicological approach to drug effects that was then accompanied by biochemical methods from the 1950s onwards, and neurochemical approaches from the 1960s and 1970s; and (b) the behaviorist notion had predecessors in psychotherapeutic approaches to addiction that emerged in the 1950s and took a psychodynamic orientation at the Institute. When the Institute positioned itself as a basic research establishment and developed a unified structure during the 1960s, these psychodynamic approaches were excluded for being "too applied." Soon afterward, behaviorist psychotherapeutic approaches to drug dependence emerged in the 1970s, emphasizing their foundation in basic research. Even though neuroscientific and behaviorist notions had some overlaps through the use of animal experimentation and by referring to basic research, researchers using the two approaches remained separate in their respective units during the time period under analysis. When conceptualizing the local scientific occupation with "drug dependence," I apply here the history of science concept of a "split object." Like the "boundary object," the split object is plastic enough to adapt to local conditions and robust enough to maintain its genuine identity. Compared with the boundary object, however, the split object does not invite scientific collaboration. It does, nonetheless, enable epistemic coexistence under a common institutional goal.