Augmentation strategies for transcranial magnetic stimulation (TMS) in the treatment of unipolar depression: a scoping review

• This scoping review maps augmentation strategies used to enhance the efficacy of transcranial magnetic stimulation in unipolar depression. • A broad range of augmentation strategies was identified, including neuromodulation, pharmacological, psychological, and alternative therapies. • Priming, meaning adding another intervention shortly before stimulation, shows particularly promising evidence. • Additional benefits may also be achieved simply by increasing the number of sessions given. • Enhanced efficacy may be achieved by combination with bright light therapy or acupuncture. Repetitive transcranial magnetic stimulation (rTMS) is an established neuromodulation treatment for depression, yet its therapeutic benefits remain limited for many patients. Augmentation – using an additional intervention to enhance treatment efficacy – is a well-established strategy in pharmacotherapy, but its application to rTMS remains underexplored. This scoping review systematically maps the peer-reviewed literature on augmentation strategies for rTMS in unipolar depression, to guide future trials and treatment development. A systematic literature search was conducted in PubMed, EMBASE, PsychInfo, Web of Science and Cochrane Central Register of Controlled Trials up to August 2024, and updated August 2025, following PRISMA guidelines. A pre-registered protocol was followed. Studies that compared the effects of standard rTMS alone and augmented rTMS in people with a current episode of unipolar depression were included. Data were extracted on study design, stimulation protocols, clinical outcomes, and adverse effects. A total of 56 studies were included (containing 2305, and 5128, participants who received augmented, and standard, rTMS). Augmentation approaches comprised additional neuromodulation interventions (such as additional rTMS sessions or personalisation of stimulation location or timing) and non-neuromodulation strategies. There is preliminary evidence for several interventions, particularly priming approaches (with priming TMS sequences or transcranial direct current stimulation, as well as use of medications that modify synaptic plasticity), extended treatment courses, and alternative therapies. This review comprehensively mapped out augmentation strategies for rTMS in unipolar depression. The findings highlight promising strategies for enhancing rTMS efficacy, warranting confirmation in future randomised controlled trials with larger sample sizes, adequate treatment duration, and longer follow-up.