Whether depression is an
independent risk factor for coronary heart disease is a million dollar question
that has remained unanswered.
There is enough evidence to associate depression
and heart disease however it is still not been given the weightage it deserves
to be called a risk factor. Despite the strong evidence the field is still
being actively explored.
Mental disorders and
coronary heart disease are significant public health issues that add up to the
global disease burden. The Global Burden of Disease (GBD) Study estimates the
premature mortality and disability of all major diseases and injuries. A GBD
study undertaken in 2001 showed that
the psychiatric condition called unipolar depressive disorders as the third
leading cause of disease burden. Ischemic heart disease Coronary heart disease (CHD)
or coronary artery disease is a narrowing of the small blood vessels that
supply blood and oxygen to the heart. CHD is also, a condition
where the blood supply of the heart muscles get compromised, ranked fourth
globally and second in high and middle-income countries in terms of global
The links between mental
disorders and cardiovascular disease have been investigated for many decades.
Depression has various direct and indirect biological effects which may explain
its link with cardiovascular disease. A number of behavioral pathways have also
been identified in the link between mental disorders and cardiovascular
The following are some
of the factors that support the behavioral pathways:
• Patients who suffer
from a mental disorder are less likely to adopt a healthy lifestyle or to
reduce cardiovascular risk factors.
• Physical activity and
diet control are less frequently undertaken and smoking and alcohol consumption
rates are often higher.
• Obesity has been
strongly associated with both cardiovascular disease and mental disorders such
as depression, bipolar disorder and panic disorder.
• Adherence to treatment
is often less in depressed patients compared to non-depressed patients.
• Depressed patients are
known to access social services less frequently and insufficient social support
has been strongly linked to the development of cardiovascular disease.
CHD is a broadly defined
term. It is known that the association is stronger with MI, i.e. Myocardial
Infarction (heart attack). The latest article published in Biomed Central, an
authentic publisher of
open access journals, explores deeper into the associations.
Authors claim that,
'there is sufficient evidence to recommend that Burden of Disease estimates
should include MDD as a risk factor for CHD, and this evidence is strongest for
CHD resulting in MI'.
Further research is
called upon to clarify the nature of this relationship. It is vital however
that further awareness is raised about major depression as a risk factor for
CHD. The authors appeal for the inclusion of major depression as a risk factor
for CHD in the 2010 GBD study.