Age differentiation in depression: biochemical aspects.

No age is immune to depression but the elderly seem especially susceptible since the incidence and prevalence is highest in the age group 55-70. At all ages the causes of depression are multiple and not fully understood. Elderly people who have been prone to depression earlier in life are especially vulnerable to major life stresses but the incidence rises even among those who have not had depressions earlier in life. Evidence based largely upon the mechanism of action of drugs specifically therapeutic for depression suggests that depression is associated with alterations in the synthesis, storage, release, and utilization of chemical neurotransmitters. Enzymes involved in these mechanisms are under genetic control. Furthermore, alterations in the activity of these enzymes occur with aging. The interaction of these biological and psychosocial changes relates to increased depression in the elderly. Treatment with tricyclic antidepressants is usually effective but must be reinforced with appropriate environmental support systems.