Differential effects of cranial electrotherapy stimulation on changes in anxiety and depression symptoms over time in patients with generalized anxiety disorder.

Background: Cranial electrotherapy stimulation (CES) is a safe and well-tolerated 6-12 week treatment that is clinically and cost effective on both anxiety and depression symptoms resulting in sustained remission of these symptoms at 12 and 24 weeks in generalized anxiety disorder (GAD) patients. The aim of the current report was to explore whether the effectiveness of CES was related to its effects on depression or anxiety over time Methods: A consecutive sample of 161 eligible patients with GAD was recruited from two publicly funded services in England while they waited for individual cognitive behaviour therapy (CBT) after failing to achieve remission on the GAD-7 with computerised CBT. They received 60 minutes per day Alpha-Stim CES for 6-12 weeks. Outcomes were changes in PHQ-9, GAD-7 score from baseline to 4, 6, 8, 12 and 24 weeks. Latent variable cross-lagged panel analysis permitted an analysis of the differential effects of anxiety and depression with CES treatment over time. Results: Anxiety at baseline significantly predicted depression at week 4 (standardized regression weight = .40, p<0.001). Depression at week 12 significantly predicted anxiety at week 24 (standardized regression weight = .28, p<0.05). Limitations: Not a randomized controlled trial but further analysis of a prospective observational cohort. High rates of loss to follow up by 24 weeks. Conclusion: Sustained effectiveness required a CES response to anxiety symptoms in first 4 weeks and improvement in depression symptoms by 12 weeks.