[Personality changes in opioid-dependent subjects in a methadone maintenance treatment program]. / Changements psychologiques au cours d'un traitement de substitution de méthadone, mesurés par l'Inventaire de Personnalité d'Eysenck.

Personality disorders and particularly antisocial personality disorders (APD) are quite frequent in opioid-dependent subjects. They show various personality traits: high neuroticism, high impulsivity, higher extraversion than the general population. Previous studies have reported that some but not all personality traits improved with treatment. In a previous study, we found a low rate of APD in a French population of opioid-dependent subjects. For this reason, we evaluated personality traits at intake and during maintenance treatment with methadone. Methods - The form A of the Eysenck Personality Inventory (EPI) was given to opioid addicts at intake and after 6 and 12 months of methadone treatment. Results - 134 subjects (96 males and 38 females) took the test at intake, 60 completed 12 months of treatment. After 12 months, the EPI Neuroticism (N) and the Extraversion-introversion (E) scale scores decreased significantly. The N score improved in the first 6 months, while the E score improved only during the second 6 months of treatment. Compared to a reference group of French normal controls, male and female opioid addicts showed high N and E scores. Demographic data and EPI scores of patients who stayed in treatment for 12 months did not differ significantly from those of dropouts (n=23). Patients with a history of suicide attempts (SA) started to use heroin at an earlier age and they showed a higher E score and a tendency for a higher N score at intake. Discussion - The two personality dimensions of the EPI changed during MMT, and the N score converged towards the score of normal controls. Opioid addicts differ from normal controls mostly in their N score. The EPI did not help to differentiate 12-month completers from dropouts. Higher E scores in patients with an SA history might reflect a higher impulsivity, which has been linked to suicidality in other patient groups.

Pharmacological models in Alzheimer's disease research.

Wider use of pharmacological models would facilitate the development of new drugs for Alzheimer's disease (AD), The two main models currently used are based on the cholinergic and glutamatergic hypotheses of AD, Although they lead to some of the attention and memory impairment observed in AD, they do not fully reproduce the AD pattern. The few studies that used a combination modeling approach, ie, the simultaneous administration of several drugs with the aim of impairing several neurotransmitters or different aspects of a single system, have reported no or marginal cumulative effect. On the basis of current understanding of glutamate and acetylcholine involvement in AD pathophysiology, we suggest that models using selective muscarinic-1 (M(1)) receptor blockers would better mimic the status of the cholinergic system in AD, This kind of model might be suitable for the assessment of drugs that do not act directly on the cholinergic system.

Memory for spatial location in 'de novo' parkinsonian patients.

A deficit in memory for spatial location was recently reported in typical non-demented parkinsonian patients ('standard'). Is this deficit related to dopamine depletion? Such an association would reinforce the suggestion that striato-frontal neuronal circuits are implicated in memory for item-specific spatial coordinates. To answer this question, we compared the performance of 10 recently diagnosed and not yet treated parkinsonian patients ('de novo'), in which the neurobiochemical deficit is considered to involve mainly the nigrostriatal dopaminergic system, to that of 14 controls matched for age, global cognitive efficiency and mood, on a visuospatial learning test. The task required little motor or constructive functions and was designed to allow control of encoding and comparison of free recall, cued recall and recognition. Compared to controls, 'de novo' patients displayed a lower performance in memory for visuospatial location of pictures, contrasting with relative preservation of verbal memory, perceptive visuospatial and executive functions. These results confirm the sensitivity of visuospatial memory even at an early stage of Parkinson's disease and suggest the implication of the nigrostriatal dopaminergic system, and associated striato-frontal neuronal circuits, in executive processes needed for spatial location learning.

Memory for spatial location is affected in Parkinson's disease.

Are the striato-frontal neuronal circuits implicated in learning of item-specific spatial coordinates? To answer this question, we compared the performance of 20 patients with Parkinson's disease to that of 14 controls matched for age, global cognitive efficiency and mood, on a visuo-spatial learning task with little involvement of motor and constructive functions, allowing control of encoding and comparison of free recall, cued recall and recognition. Compared to controls, patients showed a severe memory impairment for visuo-spatial location of pictures, contrasting with relative preservation of verbal memory, and mild difficulties in perceptive visuo-spatial and executive functions. These results implicate striato-frontal neuronal circuits in memory for spatial location.