In 2009, Harvard Medical School neuroscientist Felipe Fregni published a paper in the journal The Neuroscientist stating that Cranial Electrotherapy Stimulation is associated with increased production of serotonin and endorphins. There has been evidence that Cranial Electrotherapy Stimulation evokes changes in urinary free catecholamines and 17-ketosteroids (Briones and Rosenthal 1973), increased the number of presynaptic vesicles (Kirsch and Smith 2004), and directly engages the serotonin-releasing raphe nuclei, norepinephrine-releasing locus ceruleus, and/or other structures of the brainstem (Kirsch 2002). Researchers have proposed that the mechanisms for Cranial Electrotherapy Stimulation function in the following manner: 1) by inducing synchronous changes in the brain’s activity, 2) by altering the release of synaptic vesicles, stimulating the neurotransmitter and endorphin release and/or 3) other secondary actions such as the introduction of cortical noise and peripheral craniospinal nerve stimulation.

See below for relevant research citations:

Briones DF, Rosenthal SH. 1973. Changes in urinary free catecholamines and 17-ketosteroids with cerebral electrotherapy (electrosleep). Dis Nerv Syst 34:57-58

Bystritsky A, Kerwin L, Feusner J. 2008. A pilot study of cranial electrotherapy stimulation for generalized anxiety disorder. J Clin Psychiatry 69(3):412-7

Fregni F, Zaghi S, Acar M, Hultgren B, Boggio PS,. 2009. Non invasive brain stimulation with low-intensity electrical currents: Putative mechanisms of action for direct and alternating current stimulation. Neuroscientist Online December 29, 2009.

Kirsch D. 2002. The science behind cranial electrotherapy stimulation. 2^nd ed. Edmonton: Medical Scope Publishing Corporation.

Kirsch D, Daniel L, Smith R. 2004. Cranial electrotherapy stimulation for anxiety depression, insomnia, cognitive dysfunction, and pain. In: Rosch PJ, Markov MS, editors. Bioelectromagnetic medicine. New York: Marcel Dekker, Inc. p727-40.