Pharmacotherapy for age-related behavioral deficiencies

Piracetam and other structurally related nootropics

Nearly three decades have now passed since the discovery of the piracetam-like nootropics, compounds which exhibit cognition-enhancing properties, but for which no commonly accepted mechanism of action has been established. This review covers clinical, pharmacokinetic, biochemical and behavioural results presented in the literature from 1965 through 1992 (407 references) of piracetam, oxiracetam, pramiracetam, etiracetam, nefiracetam, aniracetam and rolziracetam and their structural analogues. The piracetam-like nootropics are capable of achieving reversal of amnesia induced by, e.g., scopolamine, electroconvulsive shock and hypoxia. Protection against barbiturate intoxication is observed and some benefit in clinical studies with patients suffering from mild to moderate degrees of dementia has been demonstrated. No affinity for the alpha 1-, alpha 2-, beta-, muscarinic, 5-hydroxytryptamine-, dopamine, adenosine-A1-, mu-opiate, gamma-aminobutyric acid (GABA) (except for nefiracetam (GABAA)), benzodiazepine and glutamate receptors has been found. The racetams possess a very low toxicity and lack serious side effects. Increased turnover of different neurotransmitters has been observed as well as other biochemical findings, e.g., inhibition of enzymes such as prolylendopeptidase. So far, no generally accepted mechanism of action has, however, emerged. We believe that the effect of the racetams is due to a potentiation of already present neurotransmission and that much evidence points in the direction of a modulated ion flux by, e.g., potentiated calcium influx through non-L-type voltage-dependent calcium channels, potentiated sodium influx through alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor gated channels or voltage-dependent channels or decreases in potassium efflux. Effects on carrier mediated ion transport are also possible.

Diagnostic and pharmacological approaches in Alzheimer's disease

Alzheimer's disease is a chronic progressive disease affecting higher intellectual functioning. The clinical diagnosis is made when the onset of illness is insidious, the course slowly progressive and all the treatable causes of dementia have been ruled out. The use of more stringent criteria has improved clinical diagnosis, but at best only 80% of patients are accurately diagnosed. Ultimately the diagnosis depends upon pathological confirmation. The neuritic plaques and neurofibrillary tangles described by Alzheimer, although not pathognomonic for the disease, continue to be the basis for pathological diagnosis. The aetiology and pathophysiology of Alzheimer's disease are presently unknown. Epidemiological studies have suggested a genetic basis for the disorder, and many biochemical studies have linked it to degeneration of central cholinergic neurons, and possibly to abnormalities of other neurotransmitter systems. A marker which would permit accurate diagnosis early in the course of disease would be of major importance to researchers and clinicians alike. No marker has been found to date, although recent research results are promising. Various pharmacological strategies have been employed in the treatment of Alzheimer's disease. More recently attempts have focused on enhancing central cholinergic transmission. Despite the well-founded rationale for these studies, results have been modest.

Cognitive enhancing agents: current status in the treatment of Alzheimer's disease

Extensive recent literature on drugs used to enhance cognitive functioning, reflects the growing social problem of dementia. Many clinical trials have been undertaken with variable success. In most cases the disorder studied has been Alzheimer's disease. The pharmacological approach has been designed to rectify the presumed pathophysiological processes characteristic of the condition. Agents tested include cerebral vasodilators, cerebral metabolic enhancers, nootropics, psychostimulants, neuropeptides and neurotransmitters with a special emphasis on drugs used to enhance cholinergic function. Ethical and practical issues concerning clinical drug trials in dementia will be discussed.

Clinical efficacy of codergocrine mesylate in children with learning difficulties

A double-blind placebo-controlled study in children showed codergocrine mesylate to be effective in improving cognitive functions and behavioural symptoms associated with learning disorders. Forty randomly grouped children of either sex were given an increasing dosage of codergocrine mesylate and followed up for 12 weeks. A significant improvement was noted in speech (acquisition of new words, comprehensibility/meaningfulness of speech), sociability, attention/concentration, comprehension and memory. Improvement in behaviour (emotional lability and cooperativeness) was also noted. Problems of assessing cognitive progress in very young children with culturally appropriate methods were encountered.

Replicated evidence on the construct validity of the SCAG (Sandoz Clinical Assessment-Geriatric) scale

Factor analysis procedures, applied to a data bank of 1165 senile patients from 21 double-blind studies, yielded 5 factors: cognitive dysfunction (4 items), interpersonal relationships (4 items), apathy (4 items), affect (3 items) and somatic function (3 items). A retrospective review of the 1165 case histories revealed that patients fell into three distinct diagnostic classes: (a) patients whose symptoms of dementia were likely associated with multiple infarcts; (b) patients with other medical disorders such as metabolic imbalances, pulmonary diseases, etc. which may have induced dementia-like symptoms; and (c) primary degenerative dementia for patients with no evidence of other intervening causes. Factor analysis applied independently to the SCAG data of each of the three groups produced similar factor constructs, thereby suggesting that results reported with this instrument are valid across different geriatric diagnostic categories.

Psychotherapy for medicare patients: can psychologists do the job?

The recent debate concerning the legitimacy of allowing psychologists to bill the government directly for psychotherapy provided to Medicare patients is critically evaluated. A review of outcome studies of psychotherapy in general and psychogeriatric studies in particular suggests that the government's insistence that further evidence be provided that psychotherapy “works” is misdirected. Given the large proportion of elderly individuals in poor mental health and data indicating that once brought into the mental health system they respond particularly well to psychotherapeutic intervention, psychologists should be granted the same eligibility status as physicians. A home-visit intervention program is outlined which would increase access to care, involve psychologists, psychiatrists, nurses, and other professionals and personnel-in-training, and monitor elderly patients' mental and physical health.