RESUMO
The effects of lithium on psychomotor performance were examined in six healthy male volunteers (aged 26-31 years) and compared with those of a similar control population. Three computerised psychomotor tests (serial reaction time, semantic reasoning and syntatic reasoning) were administered before lithium, after 5 and 22 days of lithium carbonate (800 mg/d) and 4 days and 1 month after stopping the lithium. The only significant effect was an impairment of semantic reasoning during the chronic (22 day) test. This suggests a selective effect of lithium on associative mental tasks and may explain the subjects' experience of slowing in recall of object names whilst taking lithium.
Assuntos
Cognição/efeitos dos fármacos , Lítio/farmacologia , Adulto , Humanos , Masculino , Tempo de Reação/efeitos dos fármacos , Semântica , Pensamento/efeitos dos fármacos , Comportamento Verbal/efeitos dos fármacosRESUMO
The effect of lithium on serotonin (5-HT)-mediated responses in the brain was assessed by measuring changes in the prolactin (PRL) and growth hormone (GH) responses to L-tryptophan (LTP) in eight normal subjects. On the 4th day of lithium treatment the PRL responses were significantly enhanced, and this enhancement was still apparent after 20 days' treatment. In contrast, GH responses to LTP were not altered. Lithium had no effect on platelet 5-HT content, platelet imipramine binding and platelet 5-HT receptor binding. The ability of lithium to enhance some aspects of brain 5-HT function may be important in its mode of action in manic-depressive illness and may be particularly relevant to its potentiation of the antidepressant effect of tricyclic antidepressants.
