title: Strong interactions between learned helplessness and risky decision-making in a rat gambling model.
abstract: Risky decision-making is characteristic of depression and of addictive disorders, including pathological gambling. However it is not clear whether a propensity to risky choices predisposes to depressive symptoms or whether the converse is the case. Here we tested the hypothesis that rats showing risky decision-making in a rat gambling task (rGT) would be more prone to depressive-like behaviour in the learned helplessness (LH) model. Results showed that baseline rGT choice behaviour did not predict escape deficits in the LH protocol. In contrast, exposure to the LH protocol resulted in a significant increase in risky rGT choices on retest. Unexpectedly, control rats subjected only to escapable stress in the LH protocol showed a subsequent decrease in riskier rGT choices. Further analyses indicated that the LH protocol affected primarily rats with high baseline levels of risky choices and that among these it had opposite effects in rats exposed to LH-inducing stress compared to rats exposed only to the escape trials. Together these findings suggest that while baseline risky decision making may not predict LH behaviour it interacts strongly with LH conditions in modulating subsequent decision-making behaviour. The suggested possibility that stress controllability may be a key factor should be further investigated.
authors.affiliation: Department of Psychiatry, University of Toronto, Toronto, ON, Canada.|Departments of Psychology and Pharmacology &Toxicology, University of Toronto, Toronto, ON, Canada.|Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada.
authors.forename: José N
authors.initials: JN
authors.lastname: Nobrega
authors.affiliation: Institute of Medical Science, University of Toronto, Toronto, ON, Canada.
authors.forename: Parisa S
authors.initials: PS
authors.lastname: Hedayatmofidi
authors.affiliation: Department of Psychiatry, University of Toronto, Toronto, ON, Canada.|Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada.|Institute of Medical Science, University of Toronto, Toronto, ON, Canada.
authors.forename: Daniela S
authors.initials: DS
authors.lastname: Lobo
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001362:Avoidance Learning / Q000502:physiology; D002755:Choice Behavior / Q000502:physiology*; D003657:Decision Making / Q000502:physiology*; D004924:Escape Reaction / Q000502:physiology; D005715:Gambling / Q000523:psychology*; D006380:Helplessness, Learned; D008297:Male; D011916:Rats, Inbred F344; D012309:Risk-Taking