Home-Based Transcranial Direct Current Stimulation In Major Depressive Disorder (HOME)

Inclusion Criteria: 1. Adults aged 18 years or over 2. Current episode of depression based on Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria (APA, 2013) for major depressive disorder (MDD) as assessed by structured clinical assessment, Mini-International Neuropsychiatric Interview (MINI) (Sheehan et al., 1998) 3. Having at least a moderate severity of depressive symptoms as measured by a score of at least 18 in MADRS 4. Either not taking antidepressant medication or taking a stable dose of antidepressant medication for at least 6 weeks before enrolment. 5. Either not currently in psychotherapy or in ongoing psychotherapy for at least 6 weeks before enrolment. 6. Being under the care of GP 7. Agreeable for GP to be regularly informed about study participation 8. Able to provide written, informed consent Exclusion Criteria: 1. Significant suicide risk as measured by answering 'yes' to questions 4, 5 or 6 on the Columbia Suicide Severity Rating Scale (C-SSRS) Screen (Posner et al., 2011) 2. Primary comorbid psychiatric disorder (e.g. obsessive compulsive disorder) based on DSM-5 criteria as assessed in MINI 3. Current daily use of medications that affect cortical excitability (e.g. benzodiazepines) 4. Current illicit drug use or heavy alcohol use with high risk of alcohol use disorder as measured by a score of 8 or more in Alcohol use disorders identification test consumption (AUDIT C) (Khadjesari et al., 2017; NICE, 2023) 5. History of electroconvulsive therapy (ECT), transcranial magnetic stimulation (TMS), cranial electrotherapy stimulation (CES), transcranial direct current stimulation (tDCS), deep brain stimulation (DBS), or other brain stimulation 6. History of esketamine / ketamine for treatment of depression 7. History of psychosurgery for depression 8. Having cognitive impairment (e.g. dementia) 9. Current medical disorder or neurological disorder that may mimic mood disorder (e.g. hormonal disorder, unstable heart disease) 10. Have any implant in the brain or neurocranial defect 11. Have shrapnel or any ferromagnetic material in the head 12. Have any active implantable medical device (e.g. pacemaker) 13. If female and of child-bearing potential, currently pregnant or planning to become pregnant during the study 14. Concurrent enrolment in another interventional study