Alexander. (1998). Depression and the Course of Coronary Artery Disease. Am J Psychiatry ,
This articles reviews the literature which exists on depression and coronary artery
disease. This article highlights how a relationship between depression and cardiac
mortality has been strengthened over time with the support of different studies. In the
literature review, it was found that community surveys showed an increased cardiac
mortality rate associated with depression. In five out of six studies, men with depression
were found to have higher risk of myocardial infarction. This study highlights that an
association exists between depression and cardiac mortality but a causal relationship has
not been found between the two. The study also points out that it is important to find out
wheter treatment of depression reduces cardiac mortality or not. This study concludes
that depression can have serious effects on a person’s physical health and can act asa
social and financial burden on the pateint as well as the family. Thus, it is important to
treat depression in order to overcome comorbid conditions and social problems
associated with it.
Brenda. (2001). Depression and Cardiac Mortality. Arch Gen Psychiatry , 58, 221-227.
This study aimed to study the effects of depression on cardiac events and mortality
associated with it. This prospective study was conducted on 2847 participants and the
total duration of follow up was four years. The diagnosis of major and minor depression
was made using DSM III criteria and Center for Epidemiologic Studies-Depression Scale
respectively and the effects of these two were analyzed in patients with (450 participants)
and without (2397 participants) cardiac disease after adjusting for all the other
confounding factors. The results of this study showed that the relative risk of cardiac
mortality was higher in depressed individuals as compared to non depressed individuals.
The results further showed that the relative risk increased as the severity of depression
increased, i.e. relative risk was much higher in participants with major depression as
compared to minor depression. It was also seen that not only patients with cardiac disease
are at a higher risk but depression increases the mortality risk even in healthy individuals.
This is a very strong and helpful study as it clearly identifies an association between
depression and cardiac mortality.
Burke. (2005). Depression and cortisol responses to psychological stress: a meta-analysis.
Psychoneuroendocrinology , 30, 846-56.
It has been thought that altered cortisol responses are related to depression and its
severity. Thus, this meta-analysis reviewed seven studies to find a relationship between
depression and cortisol levels in response to any stressors. In order to ensure reliability of
results, only those studies were included where structured diagnostic criteria for
depression was used; only adults were included in the study; included healthy
individuals; recorded measurable psychological stressors. The statistical analysis
involved baseline effect sizes to find differences between depressed and non depressed
individuals and two different analyses were done for stress reactivity and stress recovery.
No difference was found between the baseline effect rates and cortisol level of depressed
and non depressed individuals but higher levels of cortisol were found in depressed
individuals during recovery phase. An interesting finding in this study was the higher
cortisol levels and impaired recovery in afternoon studies and this finding was more
significant in elderly patients and those with more severe depression. Thus, the results of
this meta-analysis suggest that stress response patterns are different in depressed and non
Connerney, I. Relation between depression after coronary artery bypass surgery and 12-month
outcome: a prospective study. The Lancet , 358, 1766-1771.
Many studies exist which have found an association between depression and cardiac
events and mortality related to them. But, it is also important to find out if presence of
depression has a negative impact on the outcome of patients undergoing coronary artery
bypass surgery. This study is a prospective study which was conducted on 309 patients
who underwent CABG and were followed for a period of one year. It was found that 20%
of the patients had depression at the time of discharge from the hospital and at follow up
after one year, cardiac events were noted in a significantly higher proportion of depressed
individuals as compared to individuals who were not depressed. Thus, this study clearly
establishes the fact that depression is an independent outcome predictor after bypass
surgery and affects the course of these patients drastically. Therefore, it is important to
screen patients for depression after CABG and treat them adequately to improve
outcomes after surgery.
Groot, M. d. (2001). Association of Depression and Diabetes Complications: A Meta-Analysis.
Psychosomatic Medicine , 63, 619-630.
This is a meta-analysis which establishes the link between depression and diabetic
complications and severity of disease. In this meta-analysis 27 studies, published between
1975 and 1999, were included. During the analysis of studies, various factors were taken
into consideration. These included the sample size of the studies, type of diabetes,
statistical tests done, duration of the disease and various complications which were noted.
Only those studies were included which had a good sample size and reliable results and
the diagnosis of depression was made using a standard criteria. The statistical tests done
on the 27 studies showed a significant relationship between depression and diabetic
complications. The common diabetic complications which were noted in the studies were
retinopathy, nephropathy, neuropathy and vascular complications. This study concludes
that an association exists between depression and complications of diabetes but it is
important to establish a causal relationship between them. Thus, numerous prospective
studies are required to establish a strong relationship between depression and specific
systemic complications of diabetes.
Jonas, B. S. (2000). Symptoms of Depression as a Prospective Risk Factor for Stroke.
Psychosomatic Medicine , 62, 463-471.
This is a prospective study which was conducted on a cohort of 6095 patients from all
ethnicities. The follow up period of this study ranged from 16 to 22 years. The diagnosis
of depression at baseline was made by self reported symptoms and all the confounding
factors like age, gender, comorbid diseases, physical activity, smoking, cholesterol level,
etc, were taken into consideration. In the data analysis, adjustment for all these factors
was made and it was found that a significant association existed between depression and
stroke incidence in all ethnicities. The relative risk for stroke was much higher in black
individuals as compared to whites. This shows that association of depression with stroke
is much stronger in blacks. This study is reliable and widely applicable. This clearly
shows that depressed individuals are at a higher risk of developing stroke. Thus, high risk
individuals should be screened for depression to reduce the incidence of stroke.
Meyer. (2006). Elevated monoamine oxidase A levels in the brain: an explanation for the
monoamine imbalance of major depression. Arch Gen Psychiatry , 63, 1209-16.
The monoamine theory was developed long ago to explain the etiology of depression but
scarce evidence occurs regarding how the loss of monoamine occurs in human body of
depressed individuals. The aim of this study was to find whether high levels of
monoamine oxidase A (MAO-A) are present in individuals with depression or not. This
study included 17 patients with major depression and 17 controls with no symptoms of
depression. During the study, MAO-A density was found in different areas of brain
including prefrontal cortex, cingulated cortex, hippocampus, basal ganglia, etc. It was
found that MAO-A density was significantly higher in all the regions of the brain of
depressed individuals. This clearly shows that MAO-A plays a major role in the loss of
monoamine in depression. This study is very important in the understanding of etiology
of depression as very few similar studies exist in literature which show how the loss of
monoamine occurs in the brain.
RC, K. (2003). The epidemiology of major depressive disorder: results from the National
Comorbidity Survey Replication. JAMA , 289, 3095-105.
This study shows results from a national survey conducted from February 2001 to
December 2002 in 48 different states of America. This is an important survey as it
provides recent statistics for depression based on DSM-IV criteria. Many studies exist
and report different prevalence of depression so a nationwide study is a reliable source.
The lifetime prevalence of major depression was found to be 16.2% as was almost always
associated with other mental disorders (72.1%). It was also found that depression led to
severe disability in 59.3% of the participants and only 49.1% of the patients with major
depression received adequate treatment. This shows that major depression is common,
disabling condition in general population and is a major public health issue. It exists as a
group of mental illnesses rather than a primary entity but is not recognized earlier and is
inadequately treated. Thus, individuals should be screened for depression in primary care
Sullivan. (2000). Genetic epidemiology of major depression: review and meta-analysis. Am J
Psychiatry , 157, 1552-62.
This is a meta-analysis of different family studies, adoption studies and twin studies
conducted so far. Five family studies and five twin studies met the inclusion criteria and
were included in the analysis. The twin studies which were included showed that
depression has genetic basis as higher risk of depression was found in monozygotic twins
as compared to dizygotic twins. Familial aggregation of the disease was also noted in the
studies included. The role of environmental factors was also highlighted in a few studies.
Thus, it was concluded that depression is a multifactorial disease and has both a genetic
and environmental etiology. Therefore, it is important to understand the interplay
between these two factors to have a better understanding of the disease and its causes.
There were no differences found in the results of the studies conducted in different areas.
Thus, these findings are reliable and applicable to all individuals.
Weissman. (1999). Depressed adolescents grown up. JAMA , 281, 1701-13.
It is important to know whether major depression in adolescents affects their life later on
in adulthood or not. This study was aimed to find an answer to this question. It is a
prospective, case control study which was conducted on 73 patients with major
depression during adolescence and 37 controls with no history of any psychiatric illness.
The time period of follow up varied from 10-15 years. The main outcome measures
considered in this study were suicide rate, substance abuse, functioning and disability,
presence of other psychiatric illnesses and treatment effectiveness. It was found that
suicide rates in depressed individuals were significantly higher compared to controls. It
was also found that depressed adolescents had a higher risk of developing depression in
adulthood but there was no significant risk associated with other mental illnesses.
Depression in adolescence also led to social and functional impairment in adulthood.
Thus, depression in adolescence has an impact in adulthood as well so it is important to
diagnose and treat adolescent depression in order to improve their functioning and quality
of life in adulthood.