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Biomedical subjects

G Darcourt

Publications and source records attributed to G Darcourt.

At least 19 recordsLinked to original sources

Lack of initiative and interest in Alzheimer's disease: a single photon emission computed tomography study.

Apathy is defined as a lack of motivation. The aim of this study was to investigate the relation between two major dimensions of apathy (lack of initiative and lack of interest) and brain perfusion. in patients with Alzheimer's disease (AD). Brain perfusion was measured by single photon emission tomography (SPECT). Thirty-one AD patients were included. Lack of initiative and interest were assessed with the Apathy Inventory. Nineteen AD subjects presented a lack of initiative and interest pathological score whereas 12 AD subjects did not. The lack of initiative and interest score correlated significantly with the right frontal and the right inferior temporal lobes. The AD patients with lack of initiative and interest showed a significantly lower perfusion in the right anterior cingulate than the AD patients without lack of initiative and interest. These results derive from rather small subgroups of patients but have the interest to dismantle the complementary aspects of emotion and motivation in apathy and suggest that the latter one is more related to cingulate area.

Aged↗

Relationship between impulsivity and platelet serotonin content in adolescents.

The relationship between impulsivity and serotonin function was explored in impulsive and non-depressed adolescents. Platelet serotonin content was chosen as a peripheral indicator of central serotonin function. Impulsivity was assessed with a questionnaire. All measures were performed once a week over a 6-week period for all subjects. Subjects comprised eight adolescent inpatients who were hospitalized as a result of their impulsive acts and eight healthy age- and sex-matched control subjects. Mean platelet serotonin concentration was significantly higher in the impulsive group than in the control group. Platelet serotonin concentration was positively correlated with the intensity of impulsivity in the patient group.

Adolescent↗

Evaluation of the supervisory system in elderly subjects with and without disinhibition.

UNLABELLED: Disinhibition and irritability, defined as loss of behavioral and emotional control, are frequent in the elderly. The working hypothesis for this study was that these disorders are associated with a cognitive alteration of control processes that manifests as non-routine behavior because of the dysfunction of a general executive component known as the supervisory attentional system (SAS). METHODS: A total of 28 elderly subjects with mild cognitive impairment were recruited and divided into two groups using the Neuropsychiatric Inventory. Fourteen subjects were allocated to the disinhibited group and 14 subjects matched for age, sex and educational level formed a disinhibition-free control group. The neuropsychological battery included the following tests: Mini Mental Score Evaluation, Boston Naming test, Token test, Trail Making and Verbal Fluency. Two tasks were specifically designed to stress the SAS: 1) A specific verbal sentence arrangement task in which subjects had to use sequential reasoning with verbal material. Each test sequence consisted of a series of words shown in jumbled order. The construction of some sequences had to be done by using familiar routine associations (valid conditions). In contrast, other sequences required the overriding selection of familiar routine associations, which were inappropriate within the general context of the task (invalid conditions). 2) Using the Continuous Performance Test, four aspects were evaluated: sustained, selective, preparation and suppressive attention. RESULTS: The only group differences in neuropsychological test results were the following: 1) the sentence arrangement task. In comparison with the control group, the disinhibited group was impaired in invalid conditions and the calculated difference between the number of correct responses in invalid conditions minus that in valid conditions was significantly higher; and 2) the CPT. Disinhibited subjects had a significantly lower number of hits, exclusively in the 'suppressive attention' paradigm. These results suggest that subjects with disinhibition have impaired supervisory system function.

Aged↗

The safety and tolerability of zolpidem--an update.

Zolpidem belongs to a new class of hypnotic agents, chemically distinct from the pre-existing ones, and has a unique neuropharmacological profile. It induces sedative/hypnotic effects in rodents at doses much lower than those for anticonvulsant and myorelaxant activities. Clinically, zolpidem is indicated for the short term treatment of insomnia. It has a short half-life (2.4h), with no active metabolite, and does not accumulate during repeated administration. The pharmacokinetic profile associated with the absence of active metabolites is consistent with the short duration of action and absence of residual effects that have been observed. Polysomnographic experience indicates that zolpidem induces a sleep pattern which is similar to that of physiological sleep, and which produces either no or only minimal effects on sleep architecture after abrupt discontinuation. Aspects of the general safety of zolpidem have been studied in data obtained from healthy volunteers and patients, both adult and elderly, during its clinical development and in post-marketing experience. Zolpidem appears to be well-tolerated in adults and in the elderly, when administered in accordance with prescribing instructions. The available data indicate that, in these circumstances, the risk of abuse or dependence is minimal.

Adult↗

Initiation and supervisory processes in schizophrenia and depression.

Clinical studies show that schizophrenic and depressive subjects have problems with daily life activities, and neuropsychological studies tend to explain these problems in terms of a dysexecutive syndrome. Verbal fluency and sentence arrangement are tasks considered to focus on two aspects of the dysexecutive syndrome known as initiation and supervision processes, respectively. In this study, we assessed performance in these two tasks in schizophrenia and depression. Twenty-six schizophrenic subjects (chronic schizophrenia, DSM IV definition) were compared with 26 control subjects balanced for sex, age and educational level, and 16 depressive subjects (major depression episode, DSM IV) were compared with 11 similarly balanced control subjects. Switching and clustering scores were evaluated during a semantic fluency task as two components underlying the initiation and organization processes. Capture errors specific to failure of the supervisory system and differences between the number of correct responses in two conditions (valid/invalid) were evaluated as indexes of the supervision process in a sentence arrangement task. In the semantic fluency task, switching scores were significantly lower in the schizophrenic and depressive subjects than in their respective controls. In the sentence arrangement task, only the schizophrenic subjects made significantly more capture errors than their controls and had significantly fewer correct sequences in invalid conditions than in valid conditions. This study shows a dissociation between supervision and initiation processes in two different psychiatric populations. Initiation is impaired, but supervision is preserved in depression, whereas both initiation and supervision are impaired in schizophrenia.

Adult↗

Whole blood serotonin content, tryptophan concentrations, and impulsivity in anorexia nervosa.

BACKGROUND: We hypothesized that anorectics with or without bulimic features would differ on impulsivity and indices of central serotoninergic function (high impulsivity being correlated with reduced serotoninergic function). METHODS: For all patients impulsivity rating scales and questionnaires detailing severity of eating disorder were assessed, and whole blood serotonin concentration (5-HT), free and total tryptophan (TT) concentrations, and large neutral amino acids (LNAA) were assayed. RESULTS: Nineteen patients with anorexia nervosa were included, 10 presented associated bulimic features and nine did not. Twelve healthy matched controls were also included. Our hypothesis was not verified. However, tryptophan concentration and the ratio of tryptophan concentration to LNAA allow us to separate controls from anorectics, whereas 5-HT concentration does not. Two significant and positive correlations were found: between impulsivity and anxiety in the total anorectic population, and between anxiety and serotonin in the impulsive group. CONCLUSIONS: All measured peripheral biologic indices except 5-HT concentration may be of interest in this pathology. Impulsivity and anxiety seem to be two personality components involved in anorexia nervosa. This study lead us to the necessity of redefining impulsivity in anorexia nervosa.

Adolescent↗

Clustering and switching strategies in verbal fluency tasks: comparison between schizophrenics and healthy adults.

Verbal fluency tasks are frequently used in clinical neuropsychology. Clustering (the production of words within semantic subcategories) and switching (the ability to shift between clusters) have been described as 2 components underlying fluency performance. We compared the use of clustering and switching in schizophrenic patients and healthy subjects. Seventy-eight schizophrenic subjects (DSM-IV criteria) and 64 control participants matched for age and educational level were recruited. Negative, disorganized, and productive clinical dimensions were evaluated using the SANS and SAPS scales. The number of words generated per semantic-phonemic cluster and the number of switches were evaluated during 2 verbal fluency tasks (phonemic and semantic). In the healthy controls switching and clustering were closely related to the total number of words generated in the verbal fluency tests. The role of the 2 components was partly dependent on the specific task. Switching was prevalent in formal fluency, while both switching and clustering contributed to semantic fluency. In comparison to the healthy controls, the overall group of schizophrenic patients showed a significant impairment of switching in the formal fluency task and of both switching and clustering in the semantic fluency task, and both the negative and disorganized dimensions correlated with verbal fluency performance, the number of swtiches during the phonemic fluency task, and the clustering during semantic fluency task.

Adult↗

Use of a sequencing task designed to stress the supervisory system in schizophrenic subjects.

BACKGROUND: We investigated whether schizophrenic subjects are impaired in non-routine behaviour because of the dysfunction of a general executive component labelled, in neuropsychological terms, the supervisory system. METHODS: A specific verbal sequencing test was designed for this purpose. Subjects had to perform sequential reasoning with verbal material. Each test sequence consisted of a series of words presented in jumbled order. The construction of some sequences had to be done using familiar routine associations (valid conditions). In contrast, some other sequences required the overriding selection of familiar routine associations, which were inappropriate within the general context of the task (invalid conditions). Twenty verbal sequences (10 valid-10 invalid) were administered. Thirty-seven DMS-IV schizophrenic patients and 21 normal volunteers matched for age and educational level were recruited. RESULTS: Compared to the control group the schizophrenic group was impaired in both valid and invalid conditions. The number of 'capture errors' specific to supervisory system failure was significantly higher in the schizophrenic group and only the schizophrenic patients had significantly fewer correct sequences in invalid conditions than in valid conditions. Poor performance in invalid conditions alone was observed only among the schizophrenic subjects without a general cognitive defect. CONCLUSIONS: These findings suggest that sequencing procedures requiring an executive input are impaired in schizophrenia.

Adult↗

[Hysterical personality disorder].

The hysteric personality disorder is characterized by: 1. an intense need for affection; it is a child-like need, seeking protection and affection, making the patient subject to suggestibility and dependence, along with an erotic behaviour which is in reality associated to fear of sexuality; 2. an exaggerated and rapidly shifting expression of emotion leading to unstable, theatrical and histrionic expression of emotions giving an impression of shallowness and lack of authenticity; 3. a highly imaginative thinking pattern with flight of reality and tendency to dreaming, mythomania, memory reconstruction.

Aged↗

A single photon emission computed tomography study of cerebral regional perfusion changes induced by a learning task in subjects with mild memory impairment.

Fifteen nondemented subjects with memory complaints underwent serial single photon emission computed tomography (SPECT) studies with technetium-99m-d, l-hexamethyl-propylene amine oxime (HMPAO) as tracer. Scans were carried out under a baseline conditions and during the learning phase of the Memory Efficiency Profile (MEP), a combined visual perception and memory task developed by Rey. Results indicate a positive correlation between activation, as indexed by HMPAO uptake, and neuropsychological assessment. Right temporal activation was correlated with MEP immediate recall. The right cerebellum was correlated with both MEP immediate and delayed recall. This study suggests that SPECT can show cortical activation during cognitive performance in subjects with mild memory impairment.

Aged↗

[Efficacy of antidepressants and thymoregulators in the long-term evolution of depression].

Official recommendations pointed out the long term maintenance treatment of recurrent unipolar depression on the basis of a significant effect of antidepressants and mood-stabilizers versus placebo. The results of controlled studies, mainly using imipramine or lithium salts, have not been encouraging in term of long term prognosis, due to the limited success rate for maintenance phase ranging from 30 to 48%. The "Pittsburgh study" maximized the recurrence potential by defining patients selection on at least 3 previous episodes of unipolar depression, with the immediate previous episode being no more than 2.5 years earlier, beginning the experimental maintenance therapy phase after patients remain relatively symptom free for a total of 20 weeks, and scheduled the imipramine withdrawal in the randomly assigned placebo group by a progressive reduction of 33% per week. Survival analysis in the 5 years maintenance outcome of previously imipramine responders patients demonstrated an increased risk of depressive recurrence at the beginning of discontinuation but did not prove a true prophylactic effect. Furthermore these findings do not prove that treatment are not more effective than placebo, suggesting at least a revisitation of the clinical concept of response. The putative efficacy of biological treatment should be an operational criteria to elicit vulnerability markers, mainly in the field of sleep research.

Affect↗

Cost of anxiety disorders: impact of comorbidity.

The aim of this study was to assess the relative impact of co-mobidity and of symptom severity on the costs of caring for patients with generalized anxiety disorders (GAD). One thousand and forty-two patients with GAD according to DSM III-R were observed by psychiatrists using a cross-sectional methodology. Demographic, clinical, therapeutic as well as health care utilization data were collected at a single point in time. Patients were stratified according to prevalence of co-morbidity. An economic analysis was performed based on a societal perspective. Hospitalizations and losses of productivity were the two major components of costs both in patients with and without co-morbidity. On the other hand costs of pharmaceuticals remain a marginal component of costs associated with GAD in the two groups. Controlling for confounding variables, the prevalence of health care utilisation was found to be significantly higher in patients with co-morbidity for hospitalization, laboratory tests, medications and absenteeism from work. Most of cost components were found to be significantly higher in patients with co-morbidity. The relative risk of health care utilization was higher in patients with co-morbidity, past history of anxiety, high level of anxiety as well as in older patients. Overall our findings suggest that both co-morbidity and symptom severity play a role in cost generation in GAD patients.

Absenteeism↗

5-Methoxypsoralen: effect on the noradrenaline circadian rhythm of sleep-deprived subjects.

5-methoxypsoralen (5-MOP), a serotonin analogue, stimulates the secretion of melatonin, which plays an important role in circadian rhythm regulation. Melatonin production is essentially controlled by noradrenaline (NA). To investigate the effect of 5-MOP on the 24 hr NA rhythm, hourly plasma NA concentrations measured over 24 hr in 7 healthy young subjects who took 40 mg 5-MOP orally at 21:00 hr the evening before were compared with values obtained in drug-free subjects. All subjects were sleep-deprived and under conditions in which sympathetic nervous system activation was repeated every hour over 24 hr. In both series of patients, a significant difference was observed between mean morning values and mean night values, reflecting persistence of a circadian rhythm. In subjects given 5-MOP, a significant difference was also observed between mean afternoon values and mean night values. However, MANOVA analysis failed to find any difference between the two series of subjects. Acute administration of 5-MOP thus had no significant effect on the NA circadian rhythm under our study conditions.

5-Methoxypsoralen↗

Tryptophanemia and tyrosinemia in adolescents with impulsive behavior.

Tryptophan (TRP) and tyrosine (TYR), respectively the circulating precursors of the central serotonergic (5-HT) and catecholamine systems, were measured in eight adolescents with impulsive behavior regardless of the exact type of disorder. The 6 week study period included weekly blood sampling and clinical evaluation. The ratios of TRP and TYR to large neutral amino acids (LNAA), which indicate the availability for the synthesis of neurotransmitters, were calculated. Comparison of results with eight hospitalized controls of the same age (12.5 to 18 years) revealed lower total TRP levels in four adolescent patients, a lower TRP/LNAA ratio in three adolescents, and a lower free TRP concentration in six adolescents with discretely enhanced albuminemia. A slight increase in TYR and the TYR/LNAA ratio was noted in nearly all of the adolescent patients. Despite the heterogeneity of individual biological results, the impulsive behavior subjects in this study seemed to present abnormalities in neurotransmitter precursors.

Adolescent↗

[Hesnard and the psychological ideas of the post-war period].

Hesnard was interested in all psychological theories. His goal was to develop his own theory which he conceived of as a concept of mental illness as well as all psychic life that was "at once biological and psychological, called structural-ethical". To this end, he sought to retain from various theories whatever seemed to him "useable". With behaviorism as a starting point, he conceived "Activism", which he defined as broadened behaviorism. He accepted phenomenology, but limited it to a "method of knowledge". As for "concrete psychology" as presented by Politzer, it fascinated him to the point that he was pushed to abandon a certain number of psychoanalytical concepts. He wished to put some distance between himself and Freud. He considered him a brilliant colleague, but did not identify Freudian ideas with psychoanalysis. He criticized many of his ideas, and in particular, his metapsychological approach. He wished to build a synthetic theory which would always merit the qualifier psychoanalytical, but which would retain only a part of the Freudian work and which would include many elements from other theories.

France↗