The psychopathology of organic brain syndromes and functional psychiatric disorders in the aged has been outlined, and the various specific and non-specific physical therapies for psychiatric disorders occurring in this age group have been discussed. The indications for electroconvulsive therapy are restricted to depressions, particularly first and acute depressions in this population. Various drug therapies are successfully employed in numerous geriatric conditions. Pharmacotherapy is discussed under six headings: Substitution or replacement therapy —whenever there is a break-down of metabolic processes due to deficiency of an important factor in the complex chain of metabolism; Anticoagulants and Vasodilators — when there is sufficient evidence to believe that decreased brain metabolism plays an important role in the causation of impaired behavioural functioning and inertness; Sedatives (minor tranquillizers) — to control restlessness, tension, anxiety and insomnia; Neuroleptics (major tranquillizers) — for the treatment of psychotic symptoms, e.g. hallucinations, delusions and manneristic behaviour; and Anti-depressants — for the treatment of various depressions. It must be remembered that the general indications for these treatments are the same in geriatric as in younger patients, but the geriatric patient is often more sensitive to drugs and to the side effects they may produce.