Dorsolateral Prefrontal γ-Aminobutyric Acid in Men Predicts Individual Differences in Rash Impulsivity

Boy, Frederic; Evans, C. John; Edden, Richard A.E.; Lawrence, Andrew D.; Singh, Krish D.; Husain, Masud; Sumner, Petroc

doi:10.1016/j.biopsych.2011.05.030

« Previous Next »Biological Psychiatry
Volume 70, Issue 9 , Pages 866-872, 1 November 2011

Dorsolateral Prefrontal γ-Aminobutyric Acid in Men Predicts Individual Differences in Rash Impulsivity

Frederic Boy
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Cardiff, United Kingdom
- Address correspondence to Frederic Boy, Ph.D., Cardiff University Brain Research Imaging Centre, School of Psychology, Tower Building, Park Place, Cardiff University, Cardiff CF10 3AT UK
C. John Evans
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Cardiff, United Kingdom
Richard A.E. Edden
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University, Baltimore, Maryland
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland
Andrew D. Lawrence
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Cardiff, United Kingdom
Krish D. Singh
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Cardiff, United Kingdom
Masud Husain
- University College London (UCL) Institute of Cognitive Neuroscience and UCL Institute of Neurology, London, United Kingdom
Petroc Sumner
- Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Cardiff, United Kingdom

Received 6 January 2011; received in revised form 27 May 2011; accepted 27 May 2011. published online 15 July 2011.

Background

Impulsivity is a multifaceted personality construct associated with numerous psychiatric disorders. Recent research has characterized four facets of impulsivity: “urgency” (the tendency to act rashly especially in the context of distress or cravings); “lack of premeditation” (not envisaging the consequences of actions); “lack of perseverance” (not staying focused on a task); and “sensation seeking” (engaging in exciting activities). Urgency is particularly associated with clinical populations and problematic disinhibited behavior.

Methods

We used magnetic resonance spectroscopy to measure concentration of the inhibitory neurotransmitter γ-aminobutyric acid (GABA) in the dorsolateral prefrontal cortex (DLPFC) in two cohorts of 12 and 13 participants.

Results

We find that variation in trait urgency in healthy men correlates with GABA concentration in the DLPFC. The result was replicated in an independent cohort. More GABA predicted lower urgency scores, consistent with a role in self-control for GABA-mediated inhibitory mechanisms in DLPFC.

Conclusions

These findings help account for individual differences in self-control and thus clarify the relationship between GABA and a wide range of psychiatric disorders associated with impaired self-control.

Key Words: Externalizing, γ-aminobutyric acid receptor α-2 (GABRA2), inhibition, neurochemistry, personality, self-control, stop-signal, urgency