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Biomedical subjects

G Darcourt

Publications and source records attributed to G Darcourt.

At least 37 records · Page 2Linked to original sources
PubMed1992

Circadian variation in total plasma tryptophan. Antidepressant treatment: drugs and phase advance.

The authors investigated hourly total plasma tryptophan concentrations over a 24 hour period in 3 patients with bipolar depression during 2 types of treatment: a phase advance process and conventional antidepressant therapy. Both treatment modalities increased the 24 hour mean tryptophan levels and the amplitude of circadian tryptophan concentrations. By contrast, in a previous study, moderately decreased tryptophan levels and a blunted amplitude in the circadian rhythm were observed in these same patients in a depressive phase.

Adult↗
PubMed1992

Trimipramine: acute and lasting effects on sleep in healthy and major depressive subjects.

The acute effects of trimipramine on sleep EEG patterns were investigated in six depressed inpatients and six healthy volunteers. The effects of long-term administration were then assessed in depressed patients after 4 weeks of treatment. Sedative effects of the drug were more pronounced in healthy subjects while sleep parameters of depressed patients seemed less sensitive to the drug. Chronic effects tended to correct most of the sleep disturbances seen in depressed subjects with respect to the natural organization of sleep. The major sleep effect of trimipramine concerned REM latency which was lengthened in both groups, independently of the treatment protocol.

Adult↗
PubMed1992

Circadian rhythm in plasma noradrenaline of healthy sleep-deprived subjects.

Under normal sleep-wake conditions, noradrenaline (NA) secretions in supine subjects exhibit a weak circadian variation with a peak that occurs around noon; the sleep span is characterized by reduced NA secretion. Some investigators have reported that the circadian NA rhythm is completely obliterated during sleep deprivation. In our laboratory, plasma NA was assayed every hour for 24 h in nine healthy men 20-23 years of age. All men were deprived of sleep and were required to eat and walk around every hour to prevent sleep. However, subjects remained supine for 20 min before blood samples were collected to eliminate the effect of activity. Persistence of a slight decrease in the night concentration in several subjects, despite sleep deprivation, suggests that NA secretion may be influenced by a biological clock whose activity becomes visible when the influence of posture is removed.

Adult↗
PubMed1992

[Disorders of circadian rhythms in depression].

The authors make a synthesis of studies about circadian rhythms in depression and of hypothesis to explain them. They successively study trials on the phases, on the average levels, on the amplitude of rhythms. They conclude the most significant troubles are, shortening of latency on paradoxical sleep for phases, slump of melatonin levels, blunded amplitude of every parameter. Among possible explanations, they present and discuss a trouble of oscillators, a decrease of sensitivity to external synchronizers and a trouble in rhythm coupling.

Adrenocorticotropic Hormone↗
PubMed1990

[Sleep in depression].

Insomnia is a cardinal symptom of depression, side by side with alterations of mood and slowing down of psychomotor activities. It bears witness to a rupture in the built-in circadian rhythm: architectural changes in sleep betray a biological desynchronization. Insomnia is also a failed attempt at finding a solution to depression. Total deprivation of sleep for one night may damp down the depressive disorders, and so does partial sleep deprivation in the second part of the night during several days. This leads to the conclusion that the waking-sleep system participates in the expression of symptoms of depression or even contributes to the genesis of the disease.

Antidepressive Agents↗
PubMed1990

Diurnal variation in total plasma tryptophan in controls and in depression.

Circadian rhythms of total tryptophan were investigated by assays of hourly blood samples over 25 h. The study population consisted of four endogenously depressed patients investigated in the absence of any treatment and six healthy controls. The abnormalities detected by statistical analyses in untreated depression consisted mainly of amplitude reduction; the phase positions of the depressed patients were similar to those of the controls.

Adult↗
PubMed1990

Influence of environmental factors on suicidal behavior.

The regional distribution of completed suicide was analyzed in 19 regions of France for the years 1975 and 1983. The regional distributions of environmental variables (ambient temperature, sunlight duration, and precipitation) and of sociological factors (social cohesion, socioeconomic status, status of women, and social support) were then correlated using Pearson coefficients, stepwise regression analysis, and partial correlations. Our main finding is that environmental factors such as ambient temperature may play a role in the regional distribution of completed suicide in France. Both the stepwise regression analysis and the controlled regression analysis revealed that, among all the variables studied (environmental and sociological), the main factors affecting the regional distribution of suicide were ambient temperature and sunlight duration. To our knowledge, this is the first detailed study demonstrating a clear relationship between environmental variables and suicidal behavior. The finding may be consistent with the recent description of forms of affective disorders occurring in relationship to environmental factors.

Adult↗
PubMed1990

Open trial of a calcium antagonist, nimodipine, in acute mania.

Following previous works showing an action of calcium channel blockers in mania, this trial explores the clinical efficiency of another anticalcic agent, nimodipine, which has been selected for its specific action on the CNS. Our design has been a 7-day controlled open trial. We included six inpatients diagnosed according to DSM III-R criteria as having mild to acute mania. Evaluations have been made by clinical scales, electroencephalography, electrocardiography, and extensive biological blood tests. No other medication than nimodipine was allowed excepted i.m. droperidol in case of severe excitement. We used nimodipine at a dose of 360 mg/day. The results showed good clinical efficiency in each of our six inpatients, with an important and significant improvement of scales scores. We noticed an early and significant action on mood without important sedative effect. The treatment has been well tolerated, without biological effects. Further studies are needed, but nimodipine could be an alternative treatment to the neuroleptics with a different type of action, less sedative and more specific on mood.

Acute Disease↗
PubMed1990

5-Methoxypsoralen as a specific stimulating agent of melatonin secretion in humans.

The endocrine effects of the linear furocoumarin, 5-methoxypsoralen (Bergapten), were investigated in 11 normal adults according to a cross-over design with 2 conditions: a 1-week trial with 5-methoxypsoralen (5MOP) administered daily (40 mg/orally) at 0900 h, and after a 1-week period of washout, a similar 1-week trial with daily administrations of 5MOP at 2100 h. The subjects were living under normal nychtohemeral conditions. The plasma levels of melatonin, cortisol, TSH, PRL, and GH were evaluated by hourly blood samples over 24-h periods on the preceding day and on the last day of each condition. Our main finding is that 5MOP specifically stimulates melatonin secretion in humans, with a pronounced effect when administered during the dark phase of the day (at 2100 h). The other endocrine rhythms were unaffected by 5MOP administration. Melatonin has been shown to interact with the regulation of the human circadian system; this specific stimulation may, therefore, be of great interest in disorders associated with abnormalities of circadian rhythms.

5-Methoxypsoralen↗
PubMed1990

[Hourly serum cortisol assay over 24hr by immunoenzymology in depression].

Enzymoimmunoassays have been developed as alternatives to radioimmunoassays because they obviate the need for labelled compounds yet offering comparable specificity. The authors used an enzymoimmunoassay to investigate hourly serum cortisol levels over 24 hours in 6 patients (aged over 40 years) with endogenous depression (4 unipolar depressions, under antidepressor treatment and 2 bipolar depressions, without medication) and in 2 controls, aged 20 and 47 years. In agreement with literature data, a clear circadian rhythm was observed in controls and in the depressed patients, and hypercorticism was noted in one depressed patient. A trend towards phase advance in depression was seen in both the treated and untreated patients.

Adult↗
PubMed1989

5-Methoxypsoralen increases the sensitivity of the retina to light in humans.

The acute effect of 5-methoxypsoralen (5-MOP) on the sensitivity of the retina to visible light in humans has been studied in 11 healthy volunteers 2 h after administration of 5-MOP or placebo given at 09.00 h. Retinal sensitivity was evaluated by electroretinography at 11.00 h. 5-MOP significantly increased the sensitivity of the retina to light under photopic conditions and in the early stages of the dark adaptation period, as observed under scotopic conditions. The findings suggest that melatonin is involved in these changes.

5-Methoxypsoralen↗
PubMed1989

5-Methoxypsoralen increases evening sleepiness in humans: possible involvement of the melatonin secretion.

The acute and short-term effect of 5-methoxypsoralen (5-MOP) on daytime sleepiness was investigated in 12 healthy subjects according to a double-blind cross-over design. 5-MOP (40 mg/day) or placebo was orally administered (one week each) at 16.00 h. 5-MOP significantly increases daytime sleepiness 4 to 5 h after administration without affecting the subsequent sleep efficiency and duration. We found a positive correlation between sleepiness and melatonin levels. Our findings suggest that the melatonin secretion may play a role in the effect of 5-MOP on sleepiness in humans.

5-Methoxypsoralen↗
PubMed1989

Circadian rhythms in depression and recovery: evidence for blunted amplitude as the main chronobiological abnormality.

Circadian rhythms of body temperature, plasma cortisol, norepinephrine (NE), thyroid stimulating hormone (TSH), and melatonin were compared in 16 endogenously depressed, 15 recovered (after 3 weeks of anti-depressant treatment), and 16 normal subjects. The depressed patients showed clear circadian rhythm abnormalities, consisting mainly in amplitude reduction. This amplitude reduction was significantly correlated with the patients' Hamilton depression scores. Normal circadian profiles were restored after recovery when amplitude, in particular, was increased. Features of the circadian rhythms observed in remission may be associated with antidepressant drug effects, whereas those observed in depression resemble the circadian rhythms observed in normal subjects living under conditions of temporal isolation and those of blind subjects. Our findings suggest that depression may be related both to a weakening of the coupling processes between internal pacemakers and to an abnormal sensitivity to environmental information.

Adult↗
PubMed1989

Course of psychosis in Algeria and in France: about 342 cases observed from 1975 to 1985.

The aim of this study was to compare the evolution of psychotic patients in Algeria and in France. In 1975, 105 patients were selected in Algeria and 237 in France. Ten years later, in 1985, all these patients were interviewed. In 1985, we investigated for each subject the evolution of the following parameters: sex, age, DSM-III axis 1 and 5, marital status, social welfare work, and treatment variables. Our results indicate that the improvement of the psychosocial adaptation (DSM-III axis 5) is slightly better in Algeria than in France. Medical and social support seems to be quantitatively less important in Algeria.

Adult↗
PubMed1989

Abnormal melatonin response to 5-methoxypsoralen in dementia.

The authors investigated the melatonin response to 5-methoxypsoralen in 39 healthy adult and elderly subjects and in 13 demented, 13 depressed, and 13 schizophrenic inpatients. Subjects' plasma melatonin levels were evaluated before they took single, oral 40-mg doses of 5-methoxypsoralen and 3 hours afterward. The preliminary results indicate that the melatonin response of the pineal gland to 5-methoxypsoralen is reduced in demented patients compared to that in healthy elderly subjects. Depressed and schizophrenic patients had a normal melatonin response to the drug. This finding suggests that the pineal gland may be functionally impaired in dementia but not in depression.

Adult↗
PubMed1989

[The development of psychoses: results of a clinical survey concerning 383 cases followed during 10 years (1975-1985)].

383 psychotics patients were selected in 1975 according to the french classification (INSERM). These initial population was simultaneously subdivided according 2 types of criteria: Diagnosis criteria (DSM III Axis 1), Psychosocial adaptation criteria (DSM III axis V). For each subjects we investigates in 1985 evolution of following data previously collected in 1975: Diagnosis and psychosocial adaptation, Marital status and presence of social welfare work, Treatment variable (Hospitalization and out patient department care, neuroleptic treatment). Results indicate than: psychosocial adaptation criteria are better than diagnosis criteria for outcome judgment. most of the time there is no correlation between high quantity of care and better outcome, furthermore some time there is a correlation between high quantity of care and negative outcome, We must consider, as one explanation of this fact, that it's the more severe patients who use the higher quantity of care.

Adaptation, Psychological↗
PubMed1988

Antidepressant effect of 5-methoxypsoralen: a preliminary report.

5-Methoxypsoralen (5 MOP) administered daily (40 mg at 9 p.m.) was compared with placebo in the treatment of severe depression. The clinical response was evaluated using the Hamilton Depression Rating Scale after 1 week of treatment. Our preliminary data indicate that patients receiving 5 MOP improved significantly after 1 week, whereas patients treated with placebo did not. The stimulating effect of 5 MOP on the melatonin secretion may be involved in this clinical effect.

5-Methoxypsoralen↗