No Lunch Before Your CBT Session!

Peter Roy-Byrne, MD reviewing Verma D et al. Neuropsychopharmacology 2015 Jul 1.

In an animal study, fasting retarded the long-term development of conditioned fear and, even more importantly, enhanced its extinction.

The benefit of fear circuitry to survival suggests that other survival circuits in the brain might alter the development of fear and, possibly, its treatment. These researchers examined the behavioral and neurocircuitry effects of fasting on fear processing (classical fear conditioning with auditory stimulus and footshock) in wild-type and genetically modified male mice lacking a neuropeptide Y receptor (NPY Y4), which limits appetite.

In wild-type mice, short-term fasting before fear acquisition did not affect the learning of fear but did affect consolidation of this learning over several days. Fasting before fear extinction enhanced extinction. Extinction continued even after feeding. In genetically modified mice, fear extinction was impaired but could be observed when these mice first fasted. A specific circuit within the amygdala, from basolateral to central nucleus, was responsible for the fasting effect.

Citation(s):

Verma D et al. Hunger promotes fear extinction by activation of an amygdala microcircuit. Neuropsychopharmacology 2015 Jul 1; [e-pub].