World Health Organization (WHO) ranks major depressive disorder (MDD) as the fourth leading cause of disability worldwide.Prevalence is increasing and it will be the second leading cause of disability by 2020. In developed countries, it is already the number one cause for disabilities.
First cross national data ( Weissman,1996) on prevalence estimated the life time prevalence ( mid point) to be 10%. one year prevalence is 3.7%. later on, using diagnostic interview method (WHO) these figures were confirmed.Moussavi and associates (2007) reported 12-month prevalence of 3.2% from the massive WHO World Health Survey ( 60-countries). Bromet and co- workers (2011) reported ( WMH- 18 countries) mean lifetime prevalence of 15% and 12-month prevalence of 5.5%. High-income countries have higher prevalence.
It is surprising that people in higher income countries experience more stress than those in lower-income countries.Depression is also suggested as a disease of affluence. It is also recognised that income inequality, which is for the most part greater in high- than low- or middle-income countries, promotes a wide variety of chronic conditions including depression.
Substantial proportion of people who seek treatment for major depression have a chronic–recurrent course of illness. The finding that lifetime prevalence is 2 to 3 times that of 12-month prevalence suggests that between one third and one half of lifetime cases have recurrent episodes in a given year.
How do we examine the cost of depression?
1. Education: Depression is associated with a roughly 60% elevated odds of failure to complete secondary school than otherwise comparable youth in high-income countries.
2. Employment: Job loss leads to depression. Depression is detrimental to work progress.
3. Quality of marriage: Early onset depression is associated with low probability of marriage.Depression predicts divorce. Marital dissatisfaction and discord are strongly related to depressive symptoms and this relationship is bidirectional. Longitudinal studies consistently find that premarital history of mental disorders, including depression, predict subsequent marital violence and victimization. Recent analysis show depression as a marker rather than a risk factor for this. ( ie depression is part of substance use or disruptive behavioral disorders)
4.Parental functioning: A number of studies have documented significant associations of both maternal and paternal depression with negative parenting behaviors.
5. Role loss: Depression is associated with the highest number of days out of role at the societal level of any physical or mental disorder.Human capital value of these loss were estimated to be in the range $30.1 billion65 to $51.5 billion in USA.
6.Personal financial loss: the personal earnings and household income of people with depression are substantially lower than those of people without depression.Depression in childhood and adolescence predicts reduced income earnings in adulthood.
7.Impairment: : MDD and bipolar disorder were the mental disorders most often rated severely impairing in both developed and developing countries. None of the physical disorders considered had impairment levels as high as those for MDD or bipolar disorder despite the fact that the physical disorders included such severe conditions as cancer, diabetes, and heart disease.
8.Morbidity: It is now well established that MDD is significantly associated with a wide variety of chronic physical disorders, including arthritis, asthma, cancer, cardiovascular disease, diabetes, hypertension, chronic respiratory disorders, and a variety of chronic pain conditions.Depression is a causal risk factor, it leads to an increased prevalence of these physical disorders, with all their associated financial costs, impairments, and increased mortality risk. Depression is a consistent predictor of the subsequent first onset of coronary artery disease, stroke, diabetes, heart attacks,and certain types of cancer.
9. Mortality: Depression is associated with a significantly elevated risk of early death.This is true partly because people with depression have a high suicide risk.Depression is a risk factor for cardiovascular mortality due to heart attack and stroke among people with cardiovascular disease.
The high prevalence, early age of onset, and high persistence of depressive disorders and the fact that it is increasing should alert Governments/ employers worldwide to consider interventions.Workplace depression treatment effectiveness trials have evaluated the cost effectiveness of expanded treatment from an employer perspective and showed positive returns on investment to employers.
The proportion of people with depression who receive treatment remains low in the United States and even lower in other parts of the world. A recent US study found that only about half of workers with MDD received treatment in the year of interview and that fewer than half of treated workers received treatment consistent with published treatment guidelines.
Depression is a global disaster: This is the theme of this year’s ( TODAY) World Mental Health day.
Summary of article: The Costs of Depression: Kessler: Psychiatr Clin N Am 35 (2012) 1–14