Enhancing effects of chronic lithium on memory in the rat.

BACKGROUND: In spite of recent enrichment of neurochemical and behavioural data establishing a neuroprotective role for lithium, its primary effects on cognitive functioning remain ambiguous. This study examines chronic lithium effects on spatial working memory and long-term retention. METHODS: In three discrete experiments, rats subjected to 30 daily intraperitoneal injections (2mmol/kg) of lithium (lithium groups: serum lithium=0.5+/-0.4mEq/l, 12h post-injection) or saline (controls) were trained in 0-s delay T-maze alternation and then tested in 30-, 45- and 60-s delay alternation (Experiments 1, 2, 3, respectively). Animals from Experiment 1 were further tested in one-trial step-through passive avoidance under mild shock parameters (0.5mA, 1s). Retention was assessed 6h later. Daily lithium or saline injections continued throughout behavioural testing. RESULTS: Lithium animals were indistinguishable from controls during 0-delay alternation baseline (Experiments 1-3, accuracy>88%) but showed significantly higher accuracy than controls at 30- and 45-s delays (93% versus 85% and 92% versus 82%, Experiments 1 and 2, respectively). At 60-s delay (Experiment 3) this beneficial effect of lithium was no longer apparent (lithium and control accuracy=78%). In Experiment 4, the shock used did not support 6-h passive avoidance retention in controls, whereas lithium animals showed significant step-through latency increases. CONCLUSIONS: Chronic lithium enhanced spatial working memory and promoted long-term retention of a weak aversive contingency. The results suggest that lithium may have potential as a cognitive enhancer.

Neuropsychological assessment of cognitive function in chronic alcohol-dependent patients and patients with Alzheimer's disease.

BACKGROUND: Heavy and chronic alcohol dependence and Alzheimer's disease may share some neuropsychological characteristics. PATIENTS AND METHODS: The pattern of neuropsychological characteristics of 33 alcohol-dependent patients who reported memory disturbances were evaluated and compared to the neuropsychological performance of 38 patients with mild-stage Alzheimer's disease and 73 healthy subjects, serving as controls. Alcohol-dependent patients were examined with tools concerning the pattern of alcohol abuse and problems related to alcohol consumption. All groups completed a full battery of neuropsychological tests for the assessment of cognitive functions, such as different kinds of memory, attention, executive function etc. RESULTS: Alcohol-dependent patients fared worse compared to the control subjects in every test used. The comparison of alcohol-dependent patients versus patients with Alzheimer's disease showed that the latter are much more burdened, as far as cognition is concerned, in all aspects of memory. CONCLUSION: Alcohol-dependent patients, even if they are not demented, have mild cognitive impairment in all domains of cognition (memory and frontal functions) in comparison with controls which performed within the norms. Verbal fluency, working memory and frontal functions were impaired at the same degree in alcohol-dependent patients and in patients with Alzheimer's disease. Memory problems were more pronounced in Alzheimer's disease patients.

Illness behaviour in neurological inpatients with psychiatric morbidity.

OBJECTIVE: The aim of the present study was to examine whether psychiatric morbidity can influence the type of illness behaviour of neurological inpatients. METHODS: For this purpose, we compared neurological inpatients with and without psychiatric disorders (DSM-IIIR criteria) for the seven scales of Illness Behaviour Questionnaire (IBQ) and searched for possible differences between the two patient subgroups. RESULTS: Of the 105 neurological inpatients who participated in the study, 54 (51.4%) were diagnosed as having some type of psychiatric disorder. These patients scored significantly higher than patients without psychiatric morbidity in the scale of Irritability. A suggestive trend for higher scores in the scales of Hypochondriasis, Disease Conviction, and Affective Disturbance, and significantly lower score in the scale of Denial, in patients with psychiatric morbidity, were also found. CONCLUSION: The present study has shown that neurological inpatients with psychiatric morbidity tend to develop more intense illness behaviour than those without. The effect of psychiatric morbidity on certain components of illness behaviour in neurological patients can be taken into account when therapeutic strategies are planned.