The interaction between physical and mental health has been attracting increasing attention. People with long-term conditions are two to three times more likely to experience mental health problems than the general population. The interdependency of mental and physical health has significant implications for individual patients. Mental health problems can complicate people’s physical health conditions greatly, resulting in them spending more time in hospital, experiencing poorer clinical outcomes and lower quality of life, and requiring more intensive support from services. For older people with long term conditions, this is no different. Late-life depression is often associated with chronic illness and disability, and depressed older people are at a significantly increased risk of developing chronic conditions such as ischemic heart disease. International studies have found that depression develops among 25% of people who have a stroke, 20% of people who have coronary heart disease, 24% of people with a neurological disease, 42% of people with chronic lung disease, and 50% of people with Parkinson’s disease. Conditions such as chronic pain and rheumatoid arthritis are also known to be associated with mental health disorders such as depression.
Half of people with Parkinson’s disease may have depression, which in turn is associated with a faster progression of physical symptoms, a decrease in cognitive skills and a decline in their ability to care for themselves. It has been suggested that 24–31% of people with Parkinson’s have dementia. 30% of people with Parkinson’s disease are likely to experience hallucinations and psychotic symptoms. Psychosis among patients who have Parkinson’s disease may lead to higher hospitalisation rates, significantly increased disability, residential nursing home placement and increased risk of mortality.
There is a clear association between stroke and dementia. Evidence indicates that stroke increases the risk of dementia and cognitive impairments among older people, especially among the less aged. Prevalence rates of post-stroke dementia vary from 12.2 to 31.8% within three months to one year after a stroke. Stroke also accelerates the rate of decline among people who already have dementia.
Mental health problems are common among people affected by multiple sclerosis, which is a chronic neurological disease.
Severe head injury in early adulthood may increase the risk of dementia in older age. It is also associated with mental illness, suicidal ideation, suicide attempts and completed suicide. Some populations groups are more vulnerable to head injury, for example, more than half of all prisoners and 73.6% of male Maori prisoners have experienced at least one head injury.
The ability for people to manage these long term conditions depends on their ability to also manage their mental health needs. Self-management works if the individual is motivated and has the energy to do so. However mental health conditions like depression often reduce this, leading to poorer adherence to treatment plans. This illustrates a need for recognition that healthcare professionals also need to treat mental health conditions as well as help managing the long term condition.