The standards of physical and mental health among Indigenous Australians are poor in comparison with the wider Australian community. Research shows that although there are proportionately more Indigenous people than non-Indigenous people who refrain from drinking , those who do drink are more likely to do so at high-risk levels [1030, 1031]. Between 2008–2012, Indigenous men died from alcohol-related causes at a rate four and a half times higher than their non-Indigenous counterparts, while this rate was six times higher for Indigenous women . As a result, it is possible that heavy drinking may be normalised within some communities and this could act as a barrier to people seeking treatment .
However, alcohol is not the only substance that presents a major concern for Indigenous people. In 2008, 23% of Indigenous Australians over the age of 15 years reported using an illicit substance in the previous 12-months, and 43% reported lifetime use . Substances most commonly used included cannabis (17%), non-prescription analgesics (5%), and amphetamines (4%). Reports of ever having used illicit substances increased slightly from 40% in 2002 to 43% in 2008 . Further, d’Abbs and MacLean  have highlighted the devastating effects of volatile substance misuse and petrol-sniffing among Indigenous communities in the remote areas of Central Australia. Research has also found that Indigenous Australians are more than twice as likely to be current daily cigarette smokers as non-Indigenous Australians. The percentage of current smokers increased from 33% in 2002 to 45% in 2008, and the proportion of people who had never smoked decreased from 49% to 31% over the same period .
Indigenous people are also over-represented in inpatient mental health services, with twice as many Indigenous than non-Indigenous people hospitalised for a mental illness between 2008–2010 . Across Australia, the most common mental health conditions requiring hospitalisation were substance- induced mental and behavioural disorders (36%), schizophrenia spectrum and other psychotic disorders (25%), depressive and bipolar disorders (15%), and anxiety disorders (14%). Further, in 2012–13, Indigenous people were almost three times as likely to report high or very high levels of psychological distress . In 2008–2012, the suicide rate for Indigenous people across all age groups was double the non-Indigenous suicide rate, and five times as high for young Indigenous Australians aged 15–19 years .
It has been suggested that the factors which contribute to elevated rates of psychiatric morbidity in Indigenous communities include the destruction of social infrastructure, rapid urbanisation and poverty, cultural, spiritual and emotional alienation, loss of identity, family dislocation, and increased AOD consumption [1036-1040]. Lee and colleagues  conducted a study of Indigenous women accessing treatment for co-occurring mental health and AOD use disorders. They found that women perceived negative early life events (e.g., domestic violence, physical and sexual abuse) as being associated with the onset of their AOD and mental health conditions. They reported that comorbidity led to severe and wide- ranging negative outcomes, such as general poor health, diminished social networks, unemployment, and financial instability; and they also reported that it had a serious negative impact on their ability to care for themselves and others (e.g., with some women reporting children being removed from their care).
The trauma suffered by the stolen generations as a result of the assimilation policies of the Australian Government has direct relevance to the psychological adjustment of Indigenous Australians by severely disrupting and damaging the quality of early parent–child attachment. A number of studies have found evidence of a direct link between the quality of early relationships and the development of depression in adulthood [1042-1046]. Indigenous people may be at increased risk of poor treatment outcomes due to poor physical health, social disadvantage, comorbidity, and the burden of grief through suicide, homicide, and incarceration [1047, 1048].
Although only limited data exists regarding comorbidity specifically among Indigenous communities, Roxbee and Wallace  report that there are high rates of comorbidity, along with complexities in causality and treatment, which are unique to Australian Indigenous populations. Studies have shown an association between depression, anxiety, suicide, and alcohol dependence in Indigenous communities [1050, 1051]. In addition, frequency of alcohol consumption in Indigenous communities has been found to be correlated with hallucinations, paranoia, self-mutilation, and panic [1038, 1052, 1053]. A survey of Aboriginal admissions to Bloomfield hospital in 1995 showed significant rates of comorbidity . There is also more recent evidence to suggest that substance use and self-harm behaviour are rising in the Indigenous community [1055, 1056]. Moreover, Indigenous Australians who experience comorbid disorders are likely to have poorer outcomes than those experiencing a mental health or AOD use disorder alone . However, there is some emerging evidence that interventions for comorbid conditions can lead to beneficial outcomes in Indigenous populations. An RCT conducted by Nagel and colleagues  found that a brief intervention (motivational care planning) for Indigenous people experiencing comorbidity led to reduced symptoms of mental health and AOD use disorders.
Existing mainstream models of practice in the AOD field have overwhelmingly been developed within Western systems of knowledge. As a result, they are not necessarily generalisable to other cultures and may ignore important Indigenous perspectives and needs. Therefore, despite Indigenous Australians having a heterogeneous mix of diverse languages and customs, it is important that AOD workers be aware of general issues and try to familiarise themselves with more specific information regarding the Indigenous population in their community. Reports on this particularly vulnerable group emphasise the need for access to culturally appropriate and comprehensive services to address these problems, and the need for local links with Indigenous services and consultants [99, 1051].
Workers should also be aware of the cultural diversity within Indigenous populations, which is often overlooked . Differences in cultural identity extend to different languages, accessing traditional lands, practising traditional culture, laws and governance, as well as family and kinship structures . Recognising and responding to the complexities of Indigenous identity involves acknowledging the significance of diverse language and family groups, as well as the differences in gender relationships, all of which can involve complex relationships which determine the level of interaction between family and kin . The different forms of distress experienced by Indigenous people, as well as the different pathways to recovery, need to be identified, which depend on a diverse range of beliefs and experiences .
Following interviews with Indigenous women experiencing comorbidity, Lee and colleagues  identified a number of improvements that could be made to services to better address the needs of Indigenous people with mental health and AOD use disorders, including:
- Better integration of mental health and AOD services, and greater collaboration between these services and other organisations (e.g., housing, education).
- More promotion of available services (e.g., active presence of mental health/AOD workers at local community events).
- More information and group family support for families and carers of people with co-occurring AOD and mental health conditions.
- Support groups to be run at local services to allow clients to share experiences with others in similar situations and to reduce isolation .
- More childcare options available for clients seeking help from inpatient services.
- Greater use of outreach services in remote areas as a means of simplifying access to relevant services (e.g., rehabilitation, mental health, withdrawal management) and creating a less ‘medicalised’ environment.
- Services better addressing factors that make it difficult for people to get appointments (e.g., inflexible appointment times, unreliable transportation to services).
AOD workers may find the IRIS (described in Chapter B2) useful in assisting to identify Indigenous clients with AOD and mental health conditions and mental health risks .