A Study of Depression in Old Age Using Single-Photon Emission Computerised Tomography

There is evidence to suggest that organic cerebral changes occur in elderly depressed patients. Quantitative studies of elderly depressed patients have demonstrated that they have reduced ‘radio-attenuation’ on computerised tomography (CT) scans and as a group resembled more closely a group of demented patients than normal controls (Jacoby et al, 1983). Many biochemical changes associated with ageing are similar to the pathophysiological abnormalities in depression and in dementia (Alexopoulos et al, 1988). These changes, coupled with the high frequency of depressive syndromes in demented patients, suggest a complex relationship between depression and dementia in old age. Mahendra (1985) has suggested that a variety of brain abnormalities can produce a spectrum of clinical manifestations, ranging from depression with minimal cognitive dysfunction at one end to dementia with minimal depression at the other.