A report published in the prestigious medical journal the Lancet, indicates that depression is more disabling than some chronic diseases. The authors of the study state that depression produces the greatest decrement in health compared with angina, arthritis, asthma and diabetes. Dr Moussavi and his team say that despite the evidence on the relationship between poor health and depression, there remains a lack of parity between mental health, physical disorders and access to treatment.
Very few studies have explored the effects of depression on overall health status and, until now, compared depression directly with other chronic diseases. Yet depression is a well known and commonly associated feature of many chronic diseases and conditions. When two or more diseases or conditions co-exist (in this case depression plus a chronic physical disease) the term ‘comorbidity’ is used. The comorbidity of depression with chronic physical diseases is well documented. Various studies show:
- an increased risk of depression in people who have one or more chronic diseases.
- Lower health status in people with depression.
- Depressive episodes linked to poor health-related quality of life.
In order to study how decrements in health are associated with depression and what the added effect of depression on chronic diseases is, a sample of 245, 404 participants from 60 countries were surveyed. The measure was based on 18 health-related questions. Two questions assessed perceived general health and the remaining 16 were grouped into the categories of vision, mobility, self care, cognition, interpersonal activities, pain, sleep and energy and affect. Then, after accounting for factors such as poverty and other health conditions, the researchers concluded that depression has the largest effect on worsening health.
In the published report Dr Moussavi states:
“ The comorbid state of depression incrementally worsens health compared with depression alone, with any of the chronic diseases alone, and with any combination of chronic diseases without depression.” (p.851)
The authors conclude by indicating the urgency of addressing depression as a public health priority in order improve the health status of populations and reduce disease burden.
Moussavi, S., Chattereji, S., Verdes, E., Tandon, A., Patel, V., Ustun, B (2007) Depression, chronic diseases, and decrements in health: results from the World Health Surveys. the Lancet, 370, 851-858.