One billion people worldwide are living with a diagnosable mental health disorder, and in the first year of the COVID-19 pandemic, rates of common conditions such as depression and anxiety increased by more than 25% [59]. The rates of psychotic, mood and substance use disorders among migrants and refugees are similar to the rates in host countries although post-traumatic stress disorder is more common among refugees and asylum seekers. Also, the prevalence of depression among refugees more than five years after resettlement is higher than in the corresponding host country population [60]. Moreover, most migrants and asylum seekers living with mental health conditions do not have access to available care services, often due to a lack of capacity, limited accessibility, high costs or fear of stigma in the community [59]. In addition, different belief systems and the ability to recognise mental health issues influence migrants’ and refugees’ access to mental health services [59].

Previous reviews of the literature have identified barriers to access and use of mental health services among migrants and refugees, including problems with scheduling or restrictive timing of treatment, low social status, discrimination, and language and communication barriers [61,62,63,64,65,66,67,68].

Although the differences in the use of language about mental health issues across cultures [59] and language and communication barriers have been identified as factors affecting migrants’ and refugees’ ability to seek care, we still know little about the specific barriers to accessing mental healthcare that migrants and refugees experience when language barriers are present. Similarly, we know little about the communication needs of refugees, migrants, health and social care professionals (HSCPs) and the strategies currently used to overcome language and cultural barriers in seeking and providing mental health services. Considering the increasing number of migrants and refugees globally (including over 89.3 million displaced people) [69] as well as the urgent need for mental health support, many of them will require in a host country where language barriers are likely to occur, we highlight the need for addressing the above gaps in the literature and synthesising evidence that feeds into research, policy and practice. The findings of this review have informed the development of a cross-national survey and interview study with HSCPs, third-country nationals (TCNs) and language support providers within an EU-funded project that aims to facilitate access to and provision of mental health services.

This systematic rapid review aims to address the above gap in the literature and improve our understanding of the process of seeking, receiving and providing mental health services when language barriers are present. More specifically, the objectives of the review were to investigate the needs and preferences of HSCPs and vulnerable people who require or seek mental health support but encounter language barriers due to their limited proficiency in the language(s) of the host country (see working definition in “Methods”). We also sought to examine the difficulties experienced by these groups in seeking and/or providing mental health services when language barriers are present, as well as the strategies used to overcome language barriers and their perceived effectiveness. Equally important, we sought to identify the stage(s) in the help-seeking process and/or care trajectory at which language barriers become particularly manifest, and the strategies recommended in the literature to help people seeking mental health support and experiencing language barriers, as well as HSCPs, overcome these barriers and address needs, as this is crucial to improving the provision of mental healthcare in linguistically and culturally diverse settings.

Although we acknowledge the diversity within the refugee and migrant population along with the unique challenges each sub-group may experience, it is beyond the scope of the study to cover sub-group specific challenges. Instead, this review focuses on the challenges arising from the inability to construct a shared understanding when language barriers are present. We examine communication difficulties arising from language discordance through the lens of linguistic vulnerability [82], which we posit lies at the core of the various types of vulnerability (e.g., cultural, structural) faced by refugees and migrants. Moreover, there appears to be a causal relationship between these vulnerabilities, as an inability to understand and communicate in the language of the host country is likely to lead to structural challenges and possible experience of discrimination.