The Effects of Anodal Transcranial Direct Current Stimulation on Sleep Time and Efficiency

Area of Science:

• Neuroscience
• Sleep Science
• Military Health

Background:

• Anodal transcranial direct current stimulation (tDCS) increases arousal for up to 24 hours in healthy individuals.
• Limited research exists on tDCS effects on sleep in this population.
• Previous studies suggest prefrontal cortex stimulation may impact arousal and sleep duration.

Purpose of the Study:

• To investigate the effects of anodal tDCS on sleep patterns in active duty military personnel.
• To compare the impact of tDCS targeting the left dorsolateral prefrontal cortex (lDLPFC) versus the primary motor cortex (M1) on sleep and arousal.
• To assess tDCS effects under both sleep-deprived and non-sleep-deprived conditions.

Main Methods:

• Thirty-six military personnel were randomized into three groups: lDLPFC tDCS, M1 tDCS, or sham tDCS.
• Participants underwent a 3-week protocol including questionnaires and wrist activity monitoring for sleep assessment.
• Stimulation was administered under both sleep-deprived (26 hours sustained wakefulness) and non-sleep-deprived conditions.

Main Results:

• No significant effects on sleep were observed during non-sleep-deprived testing.
• During sleep deprivation, the lDLPFC tDCS group exhibited reduced sleep time on subsequent nights compared to M1 and sham groups.
• No adverse effects on mood or sleep quality were detected in non-sleep-deprived participants.

Conclusions:

• Single-session anodal tDCS over the lDLPFC may reduce recovery sleep duration following acute sleep deprivation in military personnel.
• tDCS does not negatively impact mood or sleep quality in individuals with normal sleep patterns.
• Findings suggest tDCS might enhance fatigue recovery from sleep loss, warranting further investigation.