Depression in the elderly: New developments
R. GOURNELLIS
Assistant Professor of Psychiatry Second Department of Psychiatry, Medical School, University of Athens, “Attikon” General Hospital, Athens

Abstract
Depression in the elderly causes a heavy burden both to patients who suffer as well as to their caregivers. Depression in the elderly is even now, and will be, much more in the near future, a major public health problem due to the great increase of life span in the western world.

The lifetime prevalence of major depression, in the elderly in the community, ranges from 1 to 4%, and of depressive symptomatology from 8 to 16%. Also, the prevalence of dysthymia in the elderly in the community is found to be about 2%. However, the prevalence of major depression increases considerably in the primary health context by (5%) , in the tertiary care by (11%) and in context of long care (12%).

Both psychological factors and biological factors contribute to the onset of depression in the elderly. In the first category belong loneliness, widowhood, social and economic exclusion, institutionalization, loss of family and friends, grief, presence of acute or chronic disease , disability and dependency . These psychologically stressful factors can trigger the emergence of illness in biologically vulnerable subjects. In the second category belong organic factors that increase the vulnerability to depression, such as drugs (β-blockers, blockers of calcium ions, digoxin, benzodiazepines, antipsychotics) or physical conditions that increase the likelihood of depression, such as hypo / hyperthyroidism, Parkinson disease, vascular disease and systemic lupus erythematosus.

Various evaluation approaches have been developed for a better differential diagnosis of depression in old age due to the highly prevalent coexistance of physical illness and depression. The assessment methods either exclude symptoms attributable to physical disease ("selective approach") or include only the "cognitive" and "emotional" symptoms of depression ("substitution approach"), or require a detailed assessment of the entirety of symptoms ("best estimate approach") or, finally, include both the cognitive and the somatic symptoms ("inclusion approach").

The clinical symptoms of depression in old age are similar to those of younger patients; nevertheless, there are also differences. In specific sub-groups of elderly with depression, like those with late-onset, or with prominent presence of vascular risk factors and deficits in executive functions, the clinical expression is often characterized by lack of depressive feelings, unexplained somatic complaints, anxiety, apathy, anhedonia, psychomotor retardation and decreased self-care. Furthermore, these patients often show elevated levels of cognitive deficits, brain atrophy, white matter hyperintensities, worse treatment prognosis and frequently delayed and/or unstable response to therapy.

The neurobiological correlates of depression in the elderly include dysfunction of the hypothalamic-pituitary-adrenal axis, hypercortisolaemia, frontal dysfunction and atrophy, decreased volume of the caudate nucleus as well as hyperintensities in the deep white matter.

It should be noted that suicidal behaviour in the elderly includes a real death intention and is connected highly with depression. It has also been shown that depression is a predictive factor of dementia. In particular, early-onset of depression has been found to be a prognostic factor for dementia at a moderate degree, while the depression accompanied by disturbance of cognitive functions (pseudodementia) and some cases of late-onset depression may be precursors to dementia.

The long-term course of geriatric depression is considered to be generally similar to that of younger adults. Delayed initiation of the disorder, apathy, cognitive dysfunction, evidence of neuroimaging lesions, incomplete remission of depressive episode, concomitant physical illness and personality disorder are linked with less favorable prognosis. It should be noted that the depression itself can be a factor of long-term stress, causing inhibition of neurogennesis, reduction of the number of neurons in the dentate gyrus, hypothalamic-pituitary-adrenal axis abnormalities, reduction of the volume of the hippocampus, reduction of the volume of the frontal lobe, cognitive deficits, activation of pro-inflammatory cytokines and finally cardiovascular disease.

The treatment of late-life depression includes close follow-up and administration of appropriate medication, if necessary. The latter includes selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine-reuptake-nhibitors (SNRIs) and nortriptyline. It is worth mentioning that brief psychotherapies (behavior-cognitive psychotherapy, family psychotherapy and problem solving) have been shown to be effective in the treatment of depression in old age. Encephalos 2011, 48(4):141-142.

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