6.1 Evidence for the use of electrotherapy for anxiety and depression

The pilot studies referred to above are clearly small-scale. Examining the literature, a pilot study published in 2008 by Bystritsky and colleagues reported improvements in anxiety ratings in six of the 12 participants with a DSM-IV diagnosis of generalised anxiety disorder (50% reduction in the Hamilton Rating Scale for Anxiety (HAM-A) scores following treatment), with adverse events 'generally mild in severity, mostly consisting of headache and nausea' (Bystritsky et al., 2008). In an independent study, Barclay and Barclay (2014) reported on a clinical trial involving a more extensive cohort of 115 participants with a primary diagnosis of an anxiety disorder, using the HAM-A and HAM-D17 rating scales. They found cranial electrotherapy stimulation (CES) to ‘significantly reduce’ anxiety and comorbid depression with 'no adverse events during the study'.

However, a Cochrane Collaboration systematic review also published in 2014, which examined the efficacy of CES 'in reducing symptoms of depression as reflected in change scores on standardized depression rating scales' reached the conclusion that 'there are insufficient methodologically rigorous studies of CES in treatment of acute depression' and that 'there is a need for double-blind randomized controlled trials' (see Kavirajan et al., 2014). Inclusion of appropriate controls, accounting for possible confounding factors are important considerations that are required to establish the empirical evidence (evidence base) for the use of electrotherapy for mood disorders.