Depression is a major public health problem 

• We can all get down from time to time. However you may well be suffering from depression if:
• you are feeling constantly low and tired (for 2 weeks or more);
• you have lost interest in your usual activities and hobbies and
• you are finding it difficult to eat and sleep. 
• About 6% of the population (3/50 people) meet the clinical criteria for depression or dysthymia (low-grade depression for more than 2 years) at any one time. 20% of those will have persistent symptoms for more than 2 years. 
• Depression is highly recurrent with 30% of affected individuals experiencing a relapse within 3 months of recovery. In the absence of maintenance medication (an antidepressant) 50% will experience a further epsiode within 2 years.
• The overall prevalence of depression appears to be rising with a lifetime prevalence of 10-20%.
• 50% will also have an anxiety disorder.
• Depression is most prevalent in the 18-44 year old age group with average age of onset at 27 years.
• People born since 1945 in industrialised countries have a higher lifetime risk and an earlier age of onset.
• Higher rates of depression among women (female to male ratio is 2:1) becomes apparent at puberty and persist across the age spectrum into old age.
• The risk of depression is doubled in those of lower socioeconomic class.
• There are significantly higher rates of depression in urban and inner city areas.
• Mortality rates are increased from natural causes (1.7 times) and suicide (19.7 times).
• Direct health care costs for treating depression exceed the respective costs of treating hypertension (high blood pressure) and diabetes put together.
• Direct health care costs are dwarfed by the indirect costs:
• days lost from work due to depression exceed all other disorders;
• the economic burden on family members and society is considerable.
• The Liberal Democrats claim depression is costing the economy £8.6bn a year – a rise of £3 billion since 1999. The Research Service of the House of Commons Library calculated the figures by multiplying average earnings by the number of people who are out of work and claim benefits (Incapacity Benefit and Severe Disability Allowance) due to depression. 

1.Keller, Archives of General Psychiatry, 1992, 49, 809-816 

2.Fombonne, Acta Psychiatrica Scandinavica, 1994, 90, 145-156

3.Kessler, Archives of General Psychiatry, 1994, 51, 8-19

4.Shorter Oxford Textbook of Psychiatry, Gelder, Harrison & Cowen, 5th edition, Oxford University Press, 2006

5.New Oxford Textbook of Psychiatry, Gelder, Lopez-Ibor & Andreasen, 1st edition, Oxford University Press, 2000