Saturday, 3 December 2011

Interconnectedness: depression and heart disease

Today's topic is slightly off the beaten track when it comes to autism research but some of the themes coming out of the research in question may link back to a few issues discussed previously.

First tulips @ Paul Whiteley 2011
Whilst a term often used as a catch-all for lots of different signs and symptoms, there are a few things to say about depression. First and foremost, depression is a real condition. We all feel down from time to time as a result of lots of different things; work, money, family, football team being relegated, etc. but depression represents something more persistent, all-encompassing and can appear alongside other symptoms. Second, depression appears for many different reasons and is linked to lots of different circumstances. Most people would probably have heard of post-natal depression or the baby blues thought to be tied into the hormonal and chemical changes which occur to new mums after their new arrival has 'left the building'. One example, but there are others. Finally it is pretty well known that depression puts a person at greater risk of developing quite a few different ailments.

Shah and colleagues* recently reported on depression and a history of suicide attempts as being risk factors for cardiovascular disease (CHD) and ischemic heart disease (IHD). Analysing data from over 7500 people, aged 17-39, following up after 15 years as part of the Third National Health and Nutrition Examination Survey and correcting for various lifestyle variables such as smoking and poor diet, the authors reported an increased risk of death associated with CHD and IHD where depression / suicide attempts were historically present. The risk was particularly marked in women; a history of suicide attempts being associated with a 14-fold adjusted risk for IHD. I might add that this is not the first time that an association between depression and heart health outcomes has been reported.

The authors suggested that these findings might be evidence for a physiological effect from depression; so lower heart rate variability, increased stress hormones or inflammation. Indeed on the topic of inflammation, other evidence and commentators have reported some interesting effects relating to depression and inflammatory markers which might tie in. My recent post on the inflammatory consequences of caring might also link to some effect also.

Cumulatively what the research in this area seems to be pointing to is that our psychological health and wellbeing might not only be linked to physiological health but also might be an important driver of risk for quite a few somatic health complaints. Trauma, such as abuse, might also produce a similar effect. There may very well be more peripheral routes from depression to physiological health problems. Without trying to sound like a stuck record, I wonder about the whole gut bacteria angle as potentially being involved also; realising that 'inter-connectedness' is a word that really should be used a lot more with regards to psychology-physiology and health-disease.

* Shah AJ. et al. Depression and history of attempted suicide as risk factors for heart disease mortality in young individuals. Archives of General Psychiatry. 2011: 68: 1135-1142.