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I am ignorant and impotent and yet, somehow or other, here I am, unhappy, no doubt, profoundly dissatisfied… In spite of everything I survive.
ALDOUS HUXLEY (1894–1964)
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Depressive illness, which is probably the greatest masquerade in general practice, is one of the commonest illnesses in medicine and often confused with other illness. Untreated, depression can result in disability and death.1 The most feared outcome is suicide. It is present in at least 17% of patients who present to GPs2 and has a 12-month prevalence of 5% and a lifetime risk of 15%.3 It is often unrecognised,1 yet moderate to severe depression is as disabling as congestive heart failure1 and with a morbidity comparable to coronary heart disease. Further, depression is the leading cause of disability for all conditions among both sexes, both in Australia and worldwide.4,5 The lifetime risk of suicide in patients diagnosed with depression is 6% and treatment halves this risk.1
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Despite being treatable, 60% of sufferers have not used any form of health service in the previous months.4 Lack of awareness, stigma and shame on behalf of the patient contribute to this. Of those receiving treatment, three-quarters will be managed in general practice.5,6 As Whiteford4 notes:
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It is clear that the main focus of activity aimed at reducing the burden of common mental health disorders in Australia is in primary care. Specialist mental health services play a supporting, but not central, role.
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Depression is a chronic relapsing organic brain disease. Its mean onset is at 27 years of age. However, 40% of sufferers present by 20 years of age.7 The average duration of episodes is 3–4 months and 40% of patients will relapse within a 12-month period.7
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The cause of depression is multifactorial, having biological, psychological and social factors. Mood disorders in general have a strong familial tendency, and the risk of developing a depressive disorder can be thought of in terms of a ‘stress-vulnerability model’. That is, an individual may have a genetically determined vulnerability and if enough stress is endured a mood disorder may result. Those who are more genetically vulnerable require less stress, but if enough stress is applied, any individual can develop a mood disorder. A significant characteristic is that it impairs thinking, leading to pessimism with negativity and a loss of drive and productivity.
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There are six clusters of depressive symptoms:
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mood, e.g. sadness, anhedonia, irritability
vegetative, e.g. sleep, appetite, sexual drive
cognitive, e.g. attention, memory, self-worth
impulse control, e.g. suicide, anger, homicide
behavioural, e.g. motivation, interests, tiredness
physical, e.g. headaches, constipation
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A useful working rule is to consider depression as an illness that dampens the five basic innate activities of humans:
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energy for activity
sex
sleep
appetite and thirst
elimination ...