Selection criteria
We included randomised controlled trials from inception till December 2021 if they
(a) examined pregnant women diagnosed with a mental disorder according to a standardized diagnostic interview based on the DSM or ICD criteria, with clinical psychiatric symptoms according to validated mental health questionnaires (e.g. EPDS > 10) or with two or more psychosocial symptoms (low-income, minority status, unsafe (home) situation, living place in a deprived area, substance abuse); (b) evaluated a psychological or pharmacological perinatal treatment, provided face-to-face or over the telephone by professional health workers, with the aim to treat or prevent mental disorders; (c) reported any of the following maternal mental health outcomes: psychiatric symptoms (validated questionnaires, e.g. EPDS, STAI), incidence rates, recovery rates or risk reduction of psychiatric disorders. Secondary outcomes are any birth, neonatal, infant or biomarker outcome. A core outcome set does not exist in this field. We excluded non-English studies, abstracts, case reports and studies including postpartum women. Also, studies on solely transcranial stimulation, food supplements, eHealth, physical treatment and interventions provided by informal health workers were excluded.