Project Details
Early Career
Status: Funded - Closed
Non-invasive vagus stimulation for resistant depression in youth – an experimental proof-of-concept
Summary
BACKGROUND: Depression among adolescents is a major risk factor for suicide, which is one of the leading causes of death in this age group. Most importantly, about 40% of children and adolescents with depression do not benefit from the treatment options available (termed: treatment resistant depression). GAP: Vagus nerve stimulation (VNS) is applied as third-line treatment for adults with treatment resistant depression with good effectiveness and safety. Transcutaneous VNS (tVNS) is also considered safe in the treatment of children and adolescents with epilepsy. Proof-of-concept studies showing that tVNS can alter depressive symptoms in children and adolescents with clinical depression are missing. HYPOTHESIS: It was hypothesized that tVNS compared to sham stimulation improves difficulties in emotion processing and emotion regulation that are characteristic for depressed children and adolescents. METHODS: The study utilized a cross-over randomized, within-subject (sham vs. tVNS), controlled (depressed vs. non-depressed controls) experimental design, including n = 33 adolescents (14-17 years of age) with clinical depression and n = 30 age- and sex-matched non-depressed controls. In a cross-randomized order participants received tVNS at a fixed intensity at the concha of the left outer ear or sham-stimulation at the left ear lobe. Three different computerized emotion recognition tasks were used to quantify different facets of emotion recognition and regulation. Simultaneous recordings of electrocardiography (ECG) and electro dermal activity (EDA) as well as sampling of saliva for the determination of α-amylase, were used to quantify effects of tVNS on autonomic nervous system function. RESULTS: tVNS had no effect on the recognition of gradually or static expressed emotions but altered response inhibition on the emotional Go/NoGo task. Specifically, tVNS increased the likelihood of omitting a response towards sad target-stimuli in adolescents with MDD, while decreasing the error rate (independent of the target emotion) in controls. Effects of acute tVNS on autonomic nervous system function were negligible. IMPACT: Acute tVNS alters the recognition of briefly presented facial expressions of negative valence in adolescents with MDD while generally increasing emotion recognition in controls. tVNS seems to specifically alter early visual processing of stimuli of negative emotional valence in MDD. These findings suggest a potential therapeutic benefit of tVNS in adolescent MDD that requires further clinical evaluation within randomized-controlled trials.
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