Issues for those with a mental illness
This information is aimed to address some of the complexities for those caring for a patient with an existing mental illness who also requires palliative care.
One in two Australians has experienced an episode of mental illness and one in five currently has symptoms. Depression, trauma and anxiety are the most common. Other conditions like schizophrenia and bipolar are less common. All conditions can lead to complexities in the treatment regime for all health professionals.
Co-morbidities often exist in patients with a mental illness which can sometimes cause or exacerbate psychiatric conditions.  Those with both physical and psychiatric pathologies will sometimes slip through the net between the two specialties. 
People with a mental illness have higher mortality rates than the general population.  Their physical complaints can be attributed to their mental illness, and in some cases delays in diagnosis and treatment are because their treating doctors are not always focusing on physical conditions.  In other cases those with a mental illness don’t seek health care or access health screening in a timely manner, or don’t report early symptoms.  It has also been suggested that in some instances (such as schizophrenia) the pain that would ordinarily take most people to the doctor is either muted or highly tolerated. If help is not sought early enough, palliative care can be the patients’ first encounter with health professionals. 
Patients will often have challenging behaviours that may make them unwelcome in health services and may decrease the quality of care they receive. Other issues such as illicit drug use or alcoholism may also impact health seeking behavior, and cause lack of trust in those providing professional support.  Palliative care or other generalist health care providers frequently do not understand the degree to which symptoms of mental illness influence the behaviors and decisions of the patient.  Some patients will have a mental health treatment order which means there are legal requirements for their treatment plan to be upheld, such as accepting medication and treatment.
A barrier to care may be the fact that professional support is inaccessible if the person is physically ill and can no longer travel independently. They also cannot access care without money or transport.
Conversations around death and dying may not be facilitated with people who have a mental illness, for fear of provoking a negative reaction, resulting in little or no support in psychological or spiritual care.  This group of people is highly vulnerable, and approaches to care should look at partnership models between mental health and palliative care services. Case conferences or family conferences can be facilitated to help address and problem solve some of these issues.
The risk of complicated bereavement appears to be no different than that of those without a mental illness, but may cause further burden in addition to the problems that they already live with.
Psychiatric advanced directives are used in some areas to allow patients to consent to or refuse future mental health treatment in the event of an incapacitating psychiatric crisis.  This is similar to when an Advance Directive is used for end-of-life decision making. However, they are never completed well, or very often, by those with a mental illness, and if they are made, may or may not be recognized or adhered to. Important conversations in relation to decision-making at the end of life are not always held with the patient but with the family instead. However, one US study, through the use of hypothetical case studies found that mental health consumers were able to participate in advance care planning in relation to complex and potentially distressing situations that may arise. The authors recommend that, because those with serious mental illness die at a younger age than the general population, it is important to begin discussions about advance directives early, such as in outpatient clinics.