Little research has been carried out in Australia on culturally and linguistically diverse (CALD) groups in AOD services – let alone on those with comorbid mental health conditions. It is not clear whether comorbidity is more common in CALD than other groups. Ethnic groups are under-represented in AOD services, but not because they have a lower prevalence of AOD use disorders [439, 1070-1072]. Rather, their under-representation is a product of many barriers to treatment including :
- Strong feelings of shame and guilt.
- Fear of stigmatisation/judgement surrounding treatment.
- Cultural differences between client and therapist.
- Confusion and lack of education or exposure to public health campaigns.
- Different expectations of treatment and difficulty clarifying these due to language barriers.
- Lack of familiarity with what AOD treatment services are available, and how to access services.
- Language difficulties which make participation in AOD treatment programs difficult.
Due to the multicultural nature of Australian society, it is imperative that AOD workers develop an awareness of issues pertaining to working with people who belong to CALD groups. Each geographic area has its own unique cultural mix and AOD workers should learn as much as possible about the cultures represented in their treatment populations. In particular, AOD workers should be aware of conventions of interpersonal communication (e.g., communication style, interpersonal interactions), expectations of family, understanding of healing, views of mental illness, and perceptions of substance use. However, it is fundamental not to make assumptions based on the client’s culture – just because he/she is from a certain cultural background, that does not mean that he/she necessarily subscribes to the values and beliefs of that culture . Reid and colleagues  recommend consultation with the separate ethnic communities to develop culturally relevant strategies for AOD treatment.
It has been suggested that information about three aspects of clients’ lives is of crucial importance when treating CALD clients :
- Context of migration: If the client migrated to Australia, why they left their country of origin, how they got to Australia, their legal status, whether they have residency, any trauma experiences in the context of their country of origin or migrating to Australia (e.g., refugees of war). Helping clients to place their AOD and mental health conditions in the context of such experiences can help to reduce shame and increase self-compassion.
- Subgroup membership: Ethnicity, gender, sexual orientation, area in which they live, refugees or immigrants, religious affiliation.
- Degree of acculturation: Traditional (client adheres completely to beliefs, values, and behaviours of his/her country of origin); bicultural (client has a mix of new and old beliefs, values, and behaviours); acculturated (client has modified his/her old beliefs, values, and behaviours in an attempt to adjust); assimilated (client has completely given up his/her old beliefs, values and behaviours and adopted those of the new country).
Even migrants from English-speaking countries are likely to struggle with cultural confusion and stresses associated with changes in environment, jobs, social supports, and lifestyle. Migrants may experience a loss in social and occupational status if their qualifications are not recognised in Australia or face issues such as high unemployment levels, overcrowded living conditions, isolation, poverty, racial discrimination, and family conflict.
Rickwood  provides a general summary of the types of problems that are specific to CALD groups in the community and makes recommendations regarding the provision of treatment services. These recommendations (such as cultural and religious awareness and the appropriate use of interpreters) would also apply to those with comorbid mental health conditions. They emphasise that there are few screening tools that have been validated for these groups. As with Indigenous clients, screening tools should be validated for CALD groups and need to be administered and interpreted with care.
Below is a range of useful points which may improve assessment and treatment in CALD clients generally:
- Where possible, and with the client’s permission, involve the family in treatment. Allow the client to pick who from his/her family or community participates.
- Try to find out before the session if the client requires an interpreter, and allow the client to make decisions about if/when an interpreter is needed. Keep in mind that even clients with basic English proficiency might benefit by having an interpreter because describing symptoms, especially feelings, can be very difficult when English is a second language. Be sure the dialect is correct and be aware that some clients may have a preferred gender for the interpreter. Allow the interpreter to brief the client on the role that they will play. Even when families are involved in the client’s treatment, it is inappropriate to use family members as interpreters. The client may not wish to divulge certain information to his/ her family, or family members may not want certain information disclosed to people outside the family, and may edit what is being said. When using interpreters, be aware that some meaning can be lost in translation and address issues of confidentiality.
- Be sure to address the client appropriately and pronounce his/her name correctly.
- Discuss the client’s expectations of treatment.
- Ensure that all treatment options are clearly explained, including rationale, and processes.
- Keep what you know about mental illness in mind but ensure that you try to understand the client’s cultural understanding of his/her problems. People from different cultures often have different views on what constitutes mental illness. The DSM-5  makes it clear that diagnoses can only be made if the person’s behaviour is abnormal within his/her culture. While there are similarities in the forms of illnesses across different cultures, the specific symptoms and signs vary for different societies. For example, a man in Australia with psychosis may talk of aliens controlling his thoughts, while a man in Fiji might blame black magic. It is also not uncommon for people from some cultures (particularly South- East Asian countries) to express psychological distress through somatic (physical) symptoms .
- Be aware that some CALD clients may come from collectivist cultures (in which greater emphasis is placed on group identity, goals, and concerns than is placed on individual ones) and may require a greater involvement of family and community for successful treatment.
- Be aware of gender and age. Some cultures may have specific concerns about appropriate gender and age relations, such as talking about some subjects with a member of the opposite sex or a younger person.
- Maintain a focus on healing, coping, or rehabilitation, rather than on cure.
- Set aside at least twice the usual time, especially if you need to use an interpreter.
- Be mindful of embarrassment and cultural taboos.
- Be clear, concrete, and specific.
- Look for verbal and non-verbal signs of discomfort or confusion. Do not take silence as consent or agreement. The client may have had negative experiences in the past when accessing services, so consider making time to discuss these experiences and learn about any discrimination they may have experienced, as this may help to build trust.
- Support the client and his/her family in accessing other relevant services. CALD clients may not have knowledge of services that are available to them, so be aware of other services that could be helpful and offer to connect them directly by making a referral and help coordinate their care (see Chapter B4) [277, 1074].