Effectiveness
Soroush Zaghi et al. published an article in the journal The Neuroscientist, finding that CES increases the production of serotonin, GABA, and endorphins. These neurochemical changes explain any positive effects that might be experienced from CES.
A meta-analysis by Klawansky et al. published in Journal of Nervous & Mental Disease "showed CES to be significantly more effective than sham treatment (p < .05)", but noted that 86% of the studies included in the review were inadequately blinded and the experimenter "knew which patients were receiving CES or sham treatment." Most studies cited as evidence for the effectiveness of CES failed to report all data necessary for meta-analysis.
Computer modeling predictions using a highly detailed anatomical model show that CES induces significant currents in cortical, sub-cortical structures like thalamus,insula,and hypothalamus, and brain-stem structures.
A bibliography by Kirsch (2002) listed 126 scientific studies of CES involving human subjects and 29 animal studies. An estimated 145 human studies have been completed, encompassing over 8800 people receiving active CES.
A study published in Journal of Cognitive Rehabilitation found that 86% of the subjects tested showed improvements in their depression, 86% in state anxiety, and 90% in trait anxiety. An 18 month follow up found 18 of the original 23 subjects available to return for testing. Overall, they performed as well or better than in the original study.
A pilot study showed that CES reduced the symptom burden of generalized anxiety disorder, with a decrease in Hamilton Anxiety Rating Scale (HARS) across a 6 week study, but the study had a small sample of participants and no control group.
A meta-analysis of eight randomly controlled trial studies assessing the efficacy of CES on anxiety found that CES improved anxiety significantly as compared with placebo/sham treatment.
A systematic review which assessed 34 controlled trials involving a total of 767 CES patients and 867 control patients reported that in 77% of studies (26 of 34), CES was found to significantly reduce anxiety.
CES research has been conducted in pain management and the reduction of anxiety in patients undergoing dental procedures.
A 3-week randomized controlled study which looked at insomnia in fibromyalgia patients found significant improvement in sleeping patterns. In a longitudinal insomnia study, subjects showed improvement of symptoms during a two-year follow-up (p<0.0008).
Several studies published in peer reviewed medical journals have found statistically significant results using CES in the treatment of depression, and anxiety.
Read more about this topic: Cranial Electrotherapy Stimulation