Effects of seven-day diazepam administration on resting-state functional connectivity in healthy volunteers: a randomized, double-blind study.

RATIONALE

Benzodiazepines, such as diazepam, are anxiolytic-sedative drugs, used for the treatment of several different disorders. The pharmacological mechanism of action of benzodiazepines is well understood; however, it remains unclear which neural networks and systems are involved in translating these neurochemical actions into their therapeutic effects.

OBJECTIVES

The objective of this study was to investigate the effects of 7-day diazepam administration compared to placebo on resting-state functional connectivity in healthy adults independent of any task.

METHODS

Thirty-four healthy participants were randomly assigned to receive either diazepam (N = 17) or placebo (15 mg daily for 7 days) and underwent resting-state functional magnetic resonance acquisition. Model-free data analysis was performed using independent component analysis and dual regression.

RESULTS

Consistent with previous research, 11 resting-state networks were identified. Increased connectivity in response to diazepam administration was found in the medial visual network and middle/inferior temporal network. Diazepam did not cause any decreases in functional connectivity.

CONCLUSIONS

Diazepam administration increases functional connectivity in areas of emotional processing independent of any task. Diazepam also enhanced functional connectivity in the medial visual system, which is a brain region rich in GABAA receptors, and shows high binding of GABAergic drugs. These increases in functional connectivity are characteristic of CNS depressants.