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Lookup NU author(s): Dr Hamid Alhaj,
Professor Hamish McAllister-WilliamsORCiD
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Synopsis: Statement of the study The neurosteroid dehydroepiandrosterone (DHEA) has been reported to improve memory in rodents. It has also been shown to have beneficial effects on mood and well-being in man. Previous memory studies in humans have focused on providing DHEA to demented or healthy elderly populations and failed to find a consistent effect. The aim of this study was to investigate the effect of DHEA on episodic memory and its neural correlates in normal young males using an event-related potentials (ERPs) technique. Methods 24 healthy male participants were examined on two occasions, following a 7-day course of oral DHEA (150mg b.d) or placebo, in a double blind, random balanced order design. ERPs were recorded during an episodic memory test. During a study phase, subjects heard words spoken in a male or female voice. Old and new words were presented visually during a test phase; subjects were requested to identify words as old or new (recognition) and if old the gender of the voice at study (recollection). ERPs associated with correctly identified new words (correct rejections: CR) and successfully recollected old words (Hit/hits: HH) were compared, with the difference believed to reflect the neural activity underlying memory retrieval. Subjective mood, memory, sexual drive, appetite and alertness were measured using a visual analogue scale (VAS) prior to ERP recordings. Summary of result DHEA had no significant effect on recognition but improved recollection (percentage accurate recollection given recognition of an old item [85.4%± 8.9 vs. 81.2%± 11.4 (mean± SD), p<0.01]. ERPs recorded with placebo replicated the previously documented “old/new” effects of higher positivity in left parietal and right frontal regions. DHEA had a robust effect on ERPs, decreasing mean voltage from 1.2 to 0.5 μV (p= 0.005) for the period 800-1400 ms post-stimulus with a significant drug by response interaction (p<0.05). This interaction was due to a specific effect of DHEA on ERPs associated with HH responses and located over the right temporo-parietal scalp. DHEA significantly improved subjective mood and memory (p< 0.05) but had no effect on the other VAS measures. Conclusion DHEA enhanced recollection, though not the less effortful task of recognition. This effect was associated with a modification of the electrophysiological correlates of recollection in the right tempo-parietal region, which may reflect neuronal recruitment of the right hippocampus. In addition, DHEA improved subjective memory and mood. These unique findings demonstrate beneficial effects of DHEA in healthy young males.
Author(s): Alhaj HA, McAllister-Williams RH
Publication type: Article
Publication status: Published
Journal: International Journal of Neuropsychopharmacology
Pages: S340-341 abstract no. P02.135
ISSN (print): 1461-1457
ISSN (electronic): 1469-5111
Publisher: Cambridge University Press