Table 1 Summary of methodology

Objective

To comprehensively synthesise the current knowledge regarding the applications of non-invasive brain stimulation (NIBS) techniques in neuropsychiatric disorders

Scope

Examination of existing literature on NIBS techniques (TMS, tDCS, tACS) in the context of neuropsychiatric disorders

Literature search

Conducted in electronic databases (PubMed, Scopus, PsycINFO) using predefined keywords and search terms

Search keywords

"Non-invasive brain stimulation", "transcranial magnetic stimulation", "TMS", "transcranial direct current stimulation", "tDCS", "transcranial alternating current stimulation", "tACS", and relevant terms for neuropsychiatric disorders

Inclusion criteria

Primary research studies, systematic reviews, and meta-analyses published in peer-reviewed journals and written in English. Focused on NIBS techniques' applications in neuropsychiatric disorders. No time limit

Exclusion criteria

Studies primarily focused on invasive brain stimulation techniques or non-neuropsychiatric disorders

Data extraction

Standardised process to extract relevant information: study characteristics, design, participant characteristics, NIBS techniques employed, targeted disorders, outcome measures, main findings, and limitations

Data synthesis

Narrative synthesis of extracted data, organising findings thematically according to specific neuropsychiatric disorders and applications of NIBS techniques