Humanitarian emergencies can impact people's psychosocial well-being and mental health. Providing mental health and psychosocial support (MHPSS) is an essential component of humanitarian aid responses. However, factors influencing the delivery MHPSS programmes have yet to be synthesised. We undertook a systematic review on the barriers to, and facilitators of, implementing and receiving MHPSS programmes delivered to populations affected by humanitarian emergencies in low- and middle-income countries.

A comprehensive search of 12 bibliographic databases, 25 websites and citation checking was undertaken. Studies published in English from 1980 onwards were included if they contained evidence on the perspectives of adults or children who had engaged in or programmes providers involved in delivering, MHPSS programmes in humanitarian settings. Thirteen studies were critically appraised and analysed thematically.

Community engagement was a key mechanism to support the successful implementation and uptake of MHPSS programmes. Establishing good relationships with parents may also be important when there is a need to communicate the value of children and young people's participation in programmes. Sufficient numbers of trained providers were essential in ensuring a range of MHPSS programmes were delivered as planned but could be challenging in resource-limited settings. Programmes need to be socially and culturally meaningful to ensure they remain appealing. Recipients also valued engagement with peers in group-based programmes and trusting and supportive relationships with providers.

The synthesis identified important factors that could improve MHPSS programme reach and appeal. Taking these factors into consideration could support future MHPSS programmes achieve their intended aims.