The relation of worry to prefrontal cortex volume in older adults with and without generalized anxiety disorder

Despite the widespread prevalence of generalized anxiety disorder (GAD) in later life, almost nothing is known about the neural aspects of worry in adults over the age of 60. Given the ongoing rapid increase in the older adult population, the relatively poor response rates to current interventions for late life GAD, and the effects of age-related changes to the brain, additional research on worry neurobiology is needed. The study group comprised 15 older GAD patients and 15 matched controls who were compared on clinical measures and brain volumes. It was expected that prefrontal cortex (PFC) volumes [medial orbital cortex (mOFC), dorsolateral cortex (DLPFC)] would show positive relations to worry scores, and weaker relations to more general measures of anxiety and depression. Negative relations were expected between amygdala volumes and worry scores. As expected, mOFC volumes were positively related to worry scores; however, DLPFC and amygdala volumes were not. The mOFC is involved in emotional decision-making under uncertain conditions and has the ability to suppress the amygdala, both of which are hypothesized functions of worry. Results are partly consistent with GAD theory and suggest that worry may involve neural areas that are also involved in the successful control of anxiety.