Glucose as an adjuvant of fear exposure psychotherapy in anxiety disorders

• Applicant: Dr. Diana Ferreira de Sá
• Subject Area: Personality Psychology, Clinical and Medical Psychology, Methodology ; Biological Psychology and Cognitive Neuroscience
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 502145457

Improving the treatment of mental disorders ranks among the central health challenges. Anxiety disorders (ADs) are the most frequent group of mental disorders, and significantly contribute to the burden of disease. Exposure therapy is commonly considered the central therapeutic component in their treatment. Still, not all patients profit and the relapse rate is considerable.Classical conditioning models represent a valuable tool to study the mechanisms of ADs. Fear extinction constitutes a valuable laboratory analogue process to exposure therapy, and predicts the success of exposure therapy.There is a raised interest in cognitive enhancers as possible adjuvants of fear extinction processes and consequently fear exposure therapy. The substances studied have however considerable secondary effects, limiting the number of patients that can benefit from them. Therefore, there is a need for efficient therapy enhancers, easy to apply and with little to none secondary effects. It has been shown that glucose can enhance human memory but to date there are no studies on its effects on fear extinction processes. In a preliminary study, we confirmed that also glucose administration enhances fear extinction. Contrary to other cognitive enhancers, glucose is not a pharmaceutical substance, is easy to apply and has no significant side effects.The aim of the proposed project is to further investigate the use of glucose as potential adjuvant treatment in exposure therapy. We plan two independent studies assessing fear reactions through affective ratings and physiological measures:Study 1 - The long-term success of exposure therapy is not only dependent on the fear extinction during exposure, but also on fear generalization processes. We aim to examine the effects of glucose on the generalization of fear. Patients with ADs tend to generalize their anxiety. Fear generalization poses a difficulty for successful therapy, because it requires not only extinction of the causative anxiety-triggering stimuli but also extinction of stimuli to which the fear reaction generalized, making exposure therapy more complex. Healthy participants will receive a glucose or placebo drink before fear extinction and generalization will be tested after. We expect that the group receiving glucose will show enhanced extinction learning and lower fear generalization.Study 2 - We aim to bridge the gap from bench-to-bedside by applying glucose administration in a clinical framework. We will investigate if glucose administration can enhance exposure effectiveness in a sample of participants with public speaking anxiety (PSA). Participants will complete a multi-day public speaking exposure procedure, similar to a standard therapeutic exposure. Glucose or placebo will be administered before the exposure procedure on two different days. We expect that participants in the glucose group show an enhanced extinction learning and thus profit more from the exposure procedure.

• DFG Programme: Research Grants
• Co-Investigator: Professorin Dr. Tanja Michael