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You are here Psychiatry > Research > Depression Neurobiology Research Group > Depression

Depression

What is depression?

Depression is a common mental health disorder that occurs in 15% of the population at some stage in their lives, with twice as many women affected as men. The core features of a depressive episode are pervasive low mood, lack of energy, lack of pleasure and an inability to enjoy life. More severe episodes are additionally associated with sleep disturbance, loss of appetite and weight loss, impaired concentration, self-neglect, retardation, hopelessness, negative thoughts and even delusions, as well as prominent suicidal ideas and suicidal acts.

Depression in Ireland

About 300,000 people may be affected by depression at any one time in Ireland. For some people a depressive episode may be self-limiting and not require any major intervention, whereas others may need to seek help from their GP or a specialist psychiatry service. About 6000 persons are admitted annually to hospital for treatment of severe, sometimes life-threatening, depression; this accounts for 30% of Irish psychiatry hospital admissions.

The cost of depression

Over 50% of people who experience one depressive episode will have further episodes, with five to nine episodes in their lifetime. Along with individual suffering and distress, depression has a major societal impact due to loss of productivity and inability to work as well as carer burden. It is the most costly brain disorder in Europe, accounting for 1% (€118 billion annually) of the total European economy. Depression is currently one of the leading causes of disability worldwide. About 4% of people who have had depression will die by suicide.

How is depression treated?

Commonly used treatments for depression include medications (e.g. antidepressants) and psychological talking therapies. Unfortunately, about third of people with moderate to severe depression do not respond sufficiently well to such standard therapies and have "treatment-resistant" depression. By the time a patient has tried four or more different antidepressant, alone or in combination, the chance of remission is about 10% with the next treatment. However, for such treatment-resistant patients the chances of recovery with electroconvulsive therapy (ECT) are about 50% and actually much higher for very severe and psychotic depressive episodes.