Acute effect of twice-daily 15 mA transcranial alternating current stimulation on treatment-resistant depression: a case series study

• Published in: General psychiatry Vol. 36; no. 6; p. e101278
• Main Authors: Zhao, Wenfeng, Wang, Huang, Leng, Haixia, Xue, Qing, Peng, Mao, Jin, Xiukun, Tan, Liucen, Pan, Na, Wang, Xuedi, Wang, Jie, Gao, Keming, Zhang, Xiangyang, Wang, Hongxing
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd 01.11.2023; BMJ Publishing Group LTD; BMJ Publishing Group
• Subjects: Antidepressants; Anxiety disorders; Bipolar disorder; Brain research; depression; depressive disorder, treatment-resistant; Electric currents; Electroconvulsive therapy; Electrodes; Electroencephalography; Females; Ketamine; Letter; Mental depression; Mental disorders; neuropsychiatry; Patients; Personality disorders; Questionnaires; Schizophrenia; Substance abuse treatment; Suicides & suicide attempts; Transcranial magnetic stimulation
• ISSN: 2517-729X; 2096-5923; 2517-729X
• DOI: 10.1136/gpsych-2023-101278

The risks of headache and potential seizure also reduce the acceptability of rTMS.7 Similar to the electrical current used in ECT, alternating current is also utilised in transcranial alternating current stimulation (tACS),8 a unique form of non-invasive brain stimulation. tACS has shown efficacy and safety in chronic insomnia,9 MDD7 and other treatment-resistant psychiatric conditions such as clozapine-resistant schizophrenia and treatment-resistant obsessive-compulsive disorder.10 Currently, however, there is no consensus on tACS procedures and parameters for different brain disorders in clinical practice and research.7 11 The electrical current frequency and amplitude, treatment sessions and electrode locations have varied widely.7 11 One of our recent studies revealed that a single session of 77.5 Hz tACS with a current amplitude of 15 mA via the forehead and both mastoids given 5 days a week for 4 weeks, totalling 20 sessions, (referred to as a once-daily protocol) is effective in reducing depressive symptoms in first episode and drug-naïve MDD.7 However, whether15 mA, 77.5 Hz tACS is effective for treating TRD remains unclear. Due to the refractory nature of TRD, we hypothesised that more sessions of tACS may effectively treat TRD. [...]in this initial study, we used the same amplitude and frequency of tACS as our previous studies7 but changed the treatment course from once a day to twice a day. [...]this study aimed to examine the acute therapeutic potential of twice-daily tACS in TRD. Exclusion criteria were: (1) axis I psychiatric disorders, including schizophrenia, bipolar disorder, manic episode, anxiety disorders (panic disorder, generalised anxiety disorder and social anxiety disorder), post-traumatic stress disorder, obsessive compulsive disorder, anorexia nervosa, bulimia nervosa, psychosis over the previous 6 months and any axis II disorders (borderline personality disorder, antisocial personality disorder, schizotypal personality disorder and narcissistic personality disorder); (2) a treatment history of ECT, modified ECT, transcranial direct current stimulation, tACS, deep brain stimulation, or TMS; (3) risk for suicide (defined as a score of ≥3 on the suicide item of HAMD-17); (4) known allergy to electrode materials; (5) inability to communicate with researchers fluently; (6) traumatic brain injury; (7) cerebrovascular or cardiovascular stents; (8) substance use disorder (abuse or dependence, as defined by DSM-IV-TR) in the previous 6 months; (9) females who are pregnant, breast feeding or have the potential for childbearing but refuse to use reliable contraceptive methods during the study.