title: Altered reward anticipation: Potential explanation for weight gain in schizophrenia?
abstract: Obesity and weight gain are severe complications of mental illness, especially schizophrenia. They result from changes in lifestyle and nutrition, side effects of medication and other, less well-understood factors. Recent studies suggest that obesity and weight gain are linked to psychopathology. Specifically, severe psychopathology is associated with greater weight dysregulation, typically weight gain. However, our knowledge about the neuroscientific basis of weight gain in schizophrenia is currently limited. We propose that altered reward anticipation, which in turn is related to striatal dopaminergic dysregulation, may explain why obesity is more prevalent in individuals with mental illness. We review evidence that reward anticipation and weight change are linked by a core deficit in dopaminergic striatal circuits. Several lines of evidence, running from animal studies to preclinical and clinical studies, suggest that striatal dopaminergic neurotransmission is a major hub for the regulation of eating behavior and that dopamine links eating behavior to other motivated behavior. From this perspective, the present review outlines a unifying perspective on dopaminergic reward anticipation as a theoretical frame to link weight gain, medication effects and psychopathology. We derive important but open empirical questions and present perspectives for new therapeutic concepts.
authors.affiliation: Department of Psychiatry and Psychotherapy, Psychiatric Hospital Zurich, Zurich, Switzerland; Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, Goethe-University, Frankfurt, Germany. Electronic address: oliver.grimm@kgu.de.
authors.forename: Oliver
authors.initials: O
authors.lastname: Grimm
authors.affiliation: Department of Psychiatry and Psychotherapy, Psychiatric Hospital Zurich, Zurich, Switzerland. Electronic address: stefan.kaiser@puk.zh.ch.
authors.forename: Stefan
authors.initials: S
authors.lastname: Kaiser
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital Zurich, University of Zurich, Switzerland. Electronic address: michaelmartin.plichta@usz.ch.
authors.forename: Michael M
authors.initials: MM
authors.lastname: Plichta
authors.affiliation: Laboratory for Social and Neural Systems Research, Department of Economics, University of Zurich, Switzerland. Electronic address: phil.tobler@econ.uzh.ch.
authors.forename: Philippe N
authors.initials: PN
authors.lastname: Tobler
mesh_terms: D003342:Corpus Striatum; D004298:Dopamine; D006801:Humans; D012201:Reward; D012559:Schizophrenia; D015430:Weight Gain
chemical_list: D004298:Dopamine