# Sweetening fear exposure: study protocol for a multi-day, randomized controlled trial to study effects of glucose in exposure sessions of participants with public speaking anxiety

**Authors:** Monika Lehnert, Tanja Michael, Lea Berger, Alexander Hauck, Diana S. Ferreira de Sá

PMC · DOI: 10.1186/s40359-026-04125-0 · BMC Psychology · 2026-02-18

## TL;DR

This study tests if giving glucose during exposure therapy helps reduce public speaking anxiety more effectively than a placebo.

## Contribution

It is the first to investigate glucose as a cognitive enhancer in a subclinical population for exposure therapy.

## Key findings

- Glucose may enhance fear extinction and consolidation during exposure therapy.
- The study protocol aims to improve exposure therapy efficacy for public speaking anxiety.
- Physiological measures like skin conductance and heart rate will assess treatment effectiveness.

## Abstract

Public speaking anxiety (PSA) is present in most individuals with social anxiety disorder (SAD). As for SAD, exposure therapy is considered the gold-standard treatment for PSA. However, it is known that not all patients benefit from it. Recent research (Hauck Behav Res Ther: 104553, 2024) suggests that glucose facilitates fear extinction and consolidation, processes crucial for psychotherapeutic success, demonstrating its potential as an adjuvant to improve the efficacy of exposure therapy. The present study aims to translate previous findings into a clinical context, by studying the effects of glucose on fear exposure for participants with PSA.

Participants with PSA will complete a spaced multi-day public speaking exposure procedure (Cheng J Behav Ther Exp Psychiatry: 54;101-107, 2017), an established and successful method of investigating treatment for PSA (Culver J Behav Ther Exp Psychiatry: 43:787-93, 2012; Niles Behav Res Ther: 68:27-36, 2015). The effectiveness of the exposure treatment will be measured through self-report assessment and the physiological measures skin conductance (SC), and heart rate (HR). Participants will be randomly assigned to receive either glucose or a placebo prior to exposure in a randomized controlled trial.

This study is the first to investigate glucose administration as cognitive enhancer in a subclinical population, emphasizing the transition from bench to bedside. We provide a detailed study protocol to increase transparency in open science as well as enabling researchers to use the detailed protocol to implement with other manipulations, to improve exposure therapy in the long run.

The online version contains supplementary material available at 10.1186/s40359-026-04125-0.

## Linked entities

- **Chemicals:** glucose (PubChem CID 5793)
- **Diseases:** social anxiety disorder (MONDO:0001247)

## Full-text entities

- **Genes:** INS (insulin) [NCBI Gene 3630] {aka IDDM, IDDM1, IDDM2, ILPR, IRDN, MODY10}, NPEPPS (aminopeptidase puromycin sensitive) [NCBI Gene 9520] {aka AAP-S, MP100, PSA}, SPIN1 (spindlin 1) [NCBI Gene 10927] {aka SPIN, TDRD24}
- **Diseases:** SUDS (MESH:D012128), Public speaking anxiety (MESH:C000719203), AD (MESH:D001008), Diabetes (MESH:D003920), Anxiety (MESH:D001007), Depression (MESH:D003866), SIAS (MESH:D000072861), Phobia (MESH:D010698), GAD-7 (MESH:C537955), epilepsy (MESH:D004827), Generalized anxiety disorder (MESH:C000726808), Conductance (MESH:D054537), mental health disorders (OMIM:603663), psychological disorders (MESH:D000067073)
- **Chemicals:** D-cycloserine (MESH:D003523), AG (MESH:D012834), Blood glucose (MESH:D001786), Cortisol (MESH:D006854), Glucose (MESH:D005947), PRPSA (-)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Full text

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## Figures

3 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12933903/full.md

## References

8 references — full list in the complete paper: https://tomesphere.com/paper/PMC12933903/full.md

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Source: https://tomesphere.com/paper/PMC12933903