Black and minority ethnic groups.

Many of the issues facing people with mental illness from black and minority ethnic groups (BME) are the same as for the white British community. Stigma, difficulties in everyday life such as problems with housing, being accepted by friends and family, finding or keeping work, are all issues that are commonly reported by those with mental health difficulties regardless of culture and background.

Barriers for BME communities.

However, research shows that people from black and ethnic communities may face increasing difficulties including higher rates of mental illness in some communities, and subsequent problems with access to the right care and treatment.

Discrimination when leaving services.

Even if your care and treatment met your needs while you were in hospital, often upon discharge discrimination in other services that you may require can lead to poor outcomes. For instance, you may not get adequate housing that is supportive of your needs, which in turn can adversely affect your mental illness through increased stress and potentially bring on a relapse.

Culture and race.

Culture and race have an important role to play in the likelihood of someone being diagnosed with mental health problems. Studies in the UK have found that people of Bangladeshi origin have a lower rate of mental illness than the general population, while a disproportionately large number of people of Irish or Afro-Caribbean origin are diagnosed with severe mental illness.
There are several potential reasons given for this difference:

Mental illness is more likely in socially-disadvantaged groups.

This may be a factor in the case of some groups. BME groups are more likely to live in poverty. However, this is probably not a factor that accounts for much of the difference, as the Bangladeshi community who have in general the lowest rates of severe mental illness, are also often amongst the most socially-disadvantaged groups studied so far.

Mental illness is more likely in groups who have recently migrated to the UK.

The stress of emigration to the UK along with the loss of family and friends (for many people their key support network) and the difficulties in adapting to a different culture and language are often blamed for the development of mental illness. Research shows that your age at time of migration is a significant factor, with older people finding such moves most stressful.

Communities living in inner cities are more likely to experience mental illness.

BME communities are mostly concentrated residentially within inner city areas. Research shows that people living in inner cities are more likely to experience mental illness.

BME groups are more likely to be picked up in a survey than white groups.

Surveys that have looked at mental illness in the UK rely on western definitions of mental illness. Cultural differences between races, such as the expression of distress could lead to a greater number of people from BME communities being labeled as having mental illness than white groups. Difficulties with access to, and use of mental health services are faced by the majority in the UK, but none more so than people from BME groups. Research suggests that there is inequality from the start.

Black Asian and Minority Ethnic (BAME) mental health (rethink.org)