A positron emission tomography (PET) study of cerebral dopamine D2 and serotonine 5-HT2A receptor occupancy in patients treated with cyamemazine (Tercian)

RATIONALE

Cyamemazine (Tercian) is an antipsychotic drug with anxiolytic properties. Recently, an in vitro study showed that cyamemazine possesses high affinity for serotonin 5-HT(2A) receptors, which was fourfold higher than its affinity for dopamine D(2) receptors (Hameg et al. 2003).

OBJECTIVES

The aim of this study is to confirm these previous data in vivo in patients treated with clinically relevant doses of Tercian.

METHODS

Eight patients received 37.5, 75, 150 or 300 mg/day of Tercian depending on their symptomatology. Dopamine D(2) and serotonin 5-HT(2A) receptor occupancies (RO) were assessed at steady-state plasma levels of cyamemazine with positron emission tomography (PET), using [(11)C]raclopride and [(11)C]N-methyl-spiperone, respectively. The effective plasma level of the drug leading to 50% of receptor occupancy was estimated by fitting RO with plasma levels of cyamemazine at the time of the PET scan.

RESULTS

Cyamemazine induced near saturation of 5-HT(2A) receptors (RO=62.1-98.2%) in the frontal cortex even at low plasma levels of the drug. On the contrary, occupancy of striatal D(2) receptors increased with plasma levels, and no saturation was obtained even at high plasma levels (RO=25.2-74.9%). The effective plasma level of cyamemazine leading to 50% of D(2) receptor occupancy was fourfold higher than that for 5-HT(2A) receptors. Accordingly, individual 5-HT(2A)/D(2) RO ratios ranged from 1.26 to 2.68. No patients presented relevant increased prolactin levels, and only mild extrapyramidal side effects were noticed on Simpson and Angus Scale.

CONCLUSION

This in vivo binding study conducted in patients confirms previous in vitro findings indicating that cyamemazine has a higher affinity for serotonin 5-HT(2A) receptors compared to dopamine D(2) receptors. In the dose range 37.5-300 mg, levels of dopamine D(2) occupancy remained below the level for motor side effects observed with typical antipsychotics and is likely to explain the low propensity of the drug to induce extrapyramidal side effects.

Restless legs syndrome and low brain iron levels in patients with haemochromatosis

Regional brain iron levels of two patients with haemochromatosis and severe restless legs syndrome (RLS) were assessed using R2' magnetic resonance imaging (MRI) sequences in both patients and in nine healthy controls. R2' relaxation rates in the patients were decreased in the substantia nigra, red nucleus, and pallidum when compared with the controls. These results indicate that local brain iron deficiency may occur in patients with haemochromatosis and suggest a role for brain iron metabolism in the pathophysiology of RLS.

Long-term sequestration of fluorinated compounds in tissues after fluvoxamine or fluoxetine treatment: a fluorine magnetic resonance spectroscopy study in vivo

Fluorine magnetic resonance spectroscopy (19F MRS), spectroscopic imaging (MRSI) and proton anatomical magnetic resonance imaging (1H MRI) were performed on brains and lower extremities of six subjects in vivo concurrently with HPLC of serum to investigate tissue and plasma drug localization and withdrawal kinetics in humans treated with fluvoxamine or fluoxetine. 19F MRS signal was unexpectedly detected in the lower extremities months after complete disappearance of signal from plasma and brain. MRSI suggested that the lower extremity fluvoxamine signal originated mainly from bone marrow. Results suggest long-term sequestration of these drugs or their metabolites mainly in bone marrow and possibly in surrounding tissue and demonstrate the usefulness of MRS to reveal drug-trapping compartments in the body.

Characterization of the CNS effects of naftidrofuryl (Praxilène) by quantitative EEG and functional MRI: a study in healthy elderly subjects

In the present study, we investigated the effects of a single and a repeated (5 days) administration of naftidrofuryl, a serotonin 5-HT2 receptor inhibitor having neuroprotective properties, on functional brain physiology in male healthy elderly subjects, using quantitative electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). Twelve subjects aged 60 +/- 3.8 years completed the quantitative EEG study, where the effects of 400 and 600 mg were assessed, and 12 other subjects (aged 56 +/- 4.7 years) completed the fMRI study, where the effect of 400 mg was assessed on the brain activation induced by the continuous performance test (CPT). Naftidrofuryl induced a transient reduction in alpha activity followed by a specific synchronisation of the 9.5- to 11-Hz EEG activity most pronounced after repeated administration. Such regimen also increased the CPT-induced brain activation visualized by way of fMRI. The results of the present study can be interpreted at the functional level that naftidrofuryl induced an improved level of vigilance or an increased capacity of alertness in healthy elderly subjects.

[Development of compounds active in insomnia: recent developments and methodological aspects]

Most pharmacotherapeutic treatments designed to treat insomnia target GABAergic activity globally in the brain. Development of new molecules having a more specific activity pathway should improve treatment efficacy and acceptance. Both subjective and objective criteria are needed to study drug efficacy. Data regarding drug effects on polysomnographic recordings are mandatory for the development of hypnotics. Whether the drug-induced sleep is comparable to normal sleep is tackled with the spectral analysis of the sleep EEG. Residual drug effects are assessed with a package of psychomotor and neurocognitive tests, and with the driving simulator test Clinical studies investigating drug efficacy and tolerability have to be conducted on large groups of patients carefully selected using polysomnographic recordings. Our knowledge about sleep will undoubtedly soon become available for treatment of insomnia.

[Personality changes in opioid-dependent subjects in a methadone maintenance treatment program]

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.

[Pilot study comparing in blind the therapeutic effect of two doses of agomelatine, melatonin- agonist and selective 5HT2c receptors antagonist, in the treatment of major depressive disorders]

RATIONALE AND METHOD

Two doses of agomelatine (S-20098), a novel potential antidepressant drug with a new pharmacological profile (melatonin agonist and selective 5HT2C antagonist), were compared in a double-blind, randomised, pilot study in order to estimate the antidepressant activity shown in preclinical data. Inpatients suffering from major depressive disorder (DSM III-R criteria) and presenting a minimal score of 25 for MADRS were selected at D-7. After one week of run-in placebo treatment, included patients received one evening dose of agomelatine (either 5 or 100 mg) for 4 to 8 weeks. Hospitalization was required at least for the first 3 weeks. Patients presenting a satisfying response to treatment (MADRS total score < 15 or decrease > or = 40% from inclusion score) could be treated as outpatients. A follow up of 2 weeks was performed after stopping the treatment. The total duration of the treatment period could vary, according to investigator's decision, between 7 and 11 weeks. Evaluation criteria included MADRS, HAMD-17, HAM-A, CGI and AMDP 5 at D0, D7, D14 and D28, and, when applicable, at D35, D42, D49 and D56. Safety evaluations included recording of adverse events, ECG monitoring and biology.

RESULTS

Thirty inpatients were selected and 28 included (14 per group). There was no major difference between groups at inclusion, neither for demographic nor evaluation criteria. One patient of each group was excluded of the ITT analysis; 19 patients completed the mandatory period up to D28: 10 in the 5 mg group and 9 in the 100 mg group; 10 patients (5 in each group) carried on the study during the optional period, up to D56 for 7 out of them (4 in the 5 mg group, 3 in the 100 mg group). Efficacy criteria showed a significant improvement in both groups, with highly significant within group evolutions (p < 0.001 whatever the criteria) and without significant difference between groups. However, better results were observed in the 5 mg group compared to the 100 mg group. Total MADRS scores then decreased from 30.7 +/- 3.5 to 14.8 +/- 6.4 in the 5 mg group vs a decrease from 31.6 +/- 4.7 to 18.6 +/- 14.8 in the 100 mg group. Furthermore, significant improvement between D14 and D28 visits were only seen in the 5 mg group. Analysis of somatic complaints (AMDP 5) showed with both treatments a strong decrease of symptoms during the study, especially for items related to sleep disorders (difficulties in falling asleep, interrupted sleep, shortened sleep, early wakening and drowsiness). Acceptability was good for both doses of agomelatine. However, there were slightly more emergent adverse events and severe treatment-related adverse events in the 100 mg group. No modifications of cardio-vascular parameters nor biological abnormalities were observed in both groups.

CONCLUSION

Preliminary clinical data with agomelatine confirm the potential antidepressant effect in accordance with positive preclinical results. There was no significant difference between 5 and 100 mg, both for efficacy and for safety. However, the data suggest that 5 mg could be a dose at least as effective and slightly better tolerated than 100 mg. Further double-blind controlled studies versus active comparators and placebo are required in order to confirm these results.

Disturbances in hypothalamo pituitary adrenal and thyroid axis identify different sleep EEG patterns in major depressed patients

This study was aimed at investigating the relationships between sleep EEG abnormalities and hypothalamo pituitary adrenal (HPA) and hypothalamo pituitary thyroid (HPT) disturbances in major depressive disorder. Post dexamethasone (DXM) cortisol levels and the dual TSH response to 08:00 h and 23:00 h TRH administration were determined after a 2 weeks wash-out period in a group of 113 DSM-IV major depressed patients (72 females aged 44.3+/-13.0 and 41 males aged 45.7+/-11) who were consecutively admitted to undergo sleep EEG recordings. Post-DXM cortisolemia, 08:00 and 23:00 post-TRH TSH values, time spent in rapid eye movement sleep (REMS), in slow wave sleep (SWS), and in stage 2 as well as time awake after sleep onset were introduced in a principal component (PC) analysis. The four 3 PC scores explaining up to 74% of the data set were further calculated for each patients and used in a cluster analysis. A three-cluster solution was retained. Controlling for the effects of age and gender, patients belonging to these three clusters could clearly be differentiated on the basis of their neuroendocrine responses and on their sleep EEG profiles. Compared to the two other clusters, cluster I (n=26) patients showed the most severe sleep continuity disturbances. Post-DXM cortisol escape and sleep architecture disturbances (consisting of a shortening of REMS latency and a decreased SWS) identified patients belonging to cluster II (n=39). Patients in cluster III (n=48) had the lowest TSH response to TRH and the less marked sleep EEG alteration. Clinical or demographic variables were unable to differentiate the three clusters. Our results suggest that different biological dysfunctions could each underlie particular neuroendocrine and sleep EEG disturbances in major depression.

[The impact of substitution treatment by methadone among opiate-dependent subjects evaluated by Addiction Severity Index and by urine tests]

Methadone maintenance treatment (MMT) has been evaluated in the United States and in a few other countries. MMT has been developed in France since 1995, and over 5 000 patients receive this treatment. However no French study has yet been published on the efficacy of MMT as assessed by a validated scale. Retention in treatment for one year has been considered as a threshold to define maintenance of treatment benefits after discharge from a methadone program; determination of retention predictors is important. Over a three year period, we evaluated patients at admission and during treatment using the Addiction Severity Index (ASI), and urine drug screening was performed weekly; 95 patients (66 males and 29 females) were evaluated at intake. Their mean age was 30.2 5.5, and they had used opioids for a mean of 10.6 5.7 years. Their ASI severity scores for drugs were over 5, showing a clear need for treatment. Female patients differed from males only in the employment-finances ASI score; 43 patients completed at least one year of treatment, after which their drug and legal composite scores significantly improved. No significant changes in their consumption of cocaine, alcohol, benzodiazepines or cannabis were found, but they smoked fewer cigarettes at 12 months. Demographics, ASI severity scores, and history of suicide attempts did not differentiate one-year completers from dropouts (n=16). However, dropouts had used more buprenorphine and less methadone in the 30 days preceding their admission, and they received a lower dose of methadone during treatment. Our population is comparable to other French MMT populations; they enter treatment after a long history of opioid dependence. The improvement found on the ASI composite scores is also similar to the improvement described in other international studies. Dropouts in our study seem to be more treatment-resistant patients, in the sense that they had used more buprenorphine before intake and were not stabilized with it; and they may have had a more negative attitude towards methadone.

[Pilot study comparing in blind the therapeutic effect of two doses of agomelatine, melatoninergic agonist and selective 5HT2C receptors antagonist, in the treatment of major depressive disorders]

Rational and method - Two doses of agomelatine (S-20098), a novel potential antidepressant drug with a new pharmacological profile (melatonin agonist and selective 5HT2C antagonist -MASSA), were compared in a double-blind, randomised, pilot study in order to estimate the antidepressant activity shown in preclinical data. Inpatients suffering from major depressive disorder (DSM III-R criteria) and presenting a minimal score of 25 for MADRS were selected at D -7. After one week of run-in placebo treatment, included patients received one evening dose of agomelatine (either 5 or 100 mg) for 4 to 8 weeks. Hospitalization was required at least for the first 3 weeks. Patients presenting a satisfying response to treatment (MADRS total score<15 or decrease 40% from inclusion score) could be treated as outpatients. A follow up of 2 weeks was performed after stopping the treatment. The total duration of the treatment period could vary, according to investigator's decision, between 7 and 11 weeks. Evaluation criteria included MADRS, HAMD-17, HAM-A, CGI and AMDP 5 at D0, D7, D14 and D28, and, when applicable, at D35, D42, D49 and D56. Safety evaluations included recording of adverse events, ECG monitoring and biology. Results - Thirty inpatients were selected and 28 included (14 per group). There was no major difference between groups at inclusion, neither for demographic nor evaluation criteria. One patient of each group was excluded of the ITT analysis; 19 patients completed the mandatory period up to D28: 10 in the 5 mg group and 9 in the 100 mg group; 10 patients (5 in each group) carried on the study during the optional period, up to D56 for 7 out of them (4 in the 5 mg group, 3 in the 100 mg group). Efficacy criteria showed a significant improvement in both groups, with highly significant within group evolutions (p<0.001 whatever the criteria) and without significant difference between groups. However, better results were observed in the 5 mg group compared to the 100 mg group. Total MADRS scores then decreased from 30.7 3.5 to 14.8 6.4 in the 5 mg group vs a decrease from 31.6 4.7 to 18.6 14.8 in the 100 mg group. Furthermore, significant improvement between D14 and D28 visits were only seen in the 5 mg group. Analysis of somatic complaints (AMDP 5) showed with both treatment a strong decrease of symptoms during the study, especially for items related to sleep disorders (difficulties for falling asleep, interrupted sleep, shortened sleep, early wakening and drowsiness). Acceptability was good for both doses of agomelatine. However, there were slightly more emergent adverse events and severe treatment-related adverse event in the 100 mg group. No modifications of cardio-vascular parameters nor biological abnormalities were observed in both groups. Conclusion - Preliminary clinical data with agomelatine confirm the potential antidepressant effect in accordance with positive preclinical results. There was no significant difference between 5 and 100 mg, both for efficacy and for safety. However, the data suggest that 5 mg could be a at least as effective and slightly better tolerated dose than 100 mg. Further double-blind controlled studies versus active comparators and placebo are required in order to confirm these results.

Effects of the selective activation of 5-HT3 receptors on sleep: a polysomnographic study in healthy volunteers

The respective role of various classes of central serotonin (5-HT) receptors in the regulation of sleep-wakefulness cycles has been the subject of many studies. Notably, it has been reported that 5-HT1A/B receptors are involved in the regulation of rapid eye movement sleep (REMS) and that 5-HT2A/C receptors participate in the control of slow wave sleep (SWS), but the role of 5-HT3 receptors is less well characterised. In this study we investigated the effects of SR 57227A, a potent and selective 5-HT3 agonist, on the sleep EEG of normal young male volunteers. SR 57227A (2.5, 5, 10, 20, 40 mg o.d. and 20 mg b.i.d.) or placebo were administered during 7 consecutive days in seven groups of ten subjects using a parallel group design. Sleep EEG recordings were performed on days 6 and 7 after an habituation session. SR 57227A produced a dose-dependent shift of REMS toward the end of the night without changing REMS and SWS duration nor altering sleep continuity. It suggests a role for the 5-HT3 receptor in the human sleep-wakefulness cycle and particularly in REMS regulation.

Lack of effect of HPA axis hyperactivity on hormonal responses to d-fenfluramine in major depressed patients: implications for pathogenesis of suicidal behaviour

There is evidence for inhibitory effects of adrenocorticosteroids on serotonergic (5-HT) activity. However, in depression the relationship between altered cortisol levels and brain 5-HT function remains to be clarified. The aim of this study was to investigate whether hypothalamic-pituitary-adrenal (HPA) axis hyperactivity is associated with 5-HT dysfunction in depressed patients, especially in those with suicidal behaviour. Cortisol levels following the dexamethasone suppression test (DST, 1 mg PO) and prolactin, corticotropin and cortisol responses to the d-fenfluramine test (d-FEN, 45 mg PO) - a specific 5-HT releaser/uptake inhibitor - were measured in 71 drug-free DSM-IV major depressed inpatients (40 with a history of suicide attempt, 31 without) and 34 hospitalized healthy control subjects. Depressed patients showed higher post-DST cortisol levels but similar responses to d-FEN compared with control subjects. Hormonal responses to d-FEN were not correlated with cortisol levels (basal or post-DST). Among the depressed patients, DST suppressors and DST nonsuppressors exhibited no significant difference in endocrine responses to d-FEN. However, patients with a history of suicide attempt, when compared with patients without such a history, showed lower hormonal responses to d-FEN but comparable basal and post-DST cortisol levels. Taken together these results suggest that, in depression, HPA axis hyperactivity is not responsible for the reduced 5-HT activity found in patients with a history of suicidal behavior.

Morning and evening TSH response to TRH and sleep EEG disturbances in major depressive disorder

1. The aim of this study was to investigate hypothalamo-pituitary-thyroid axis (HPTA) functioning and sleep EEG disturbances in major depressive disorder. 2. Thyroid function was evaluated by determination of TSH levels before and after 8 AM and 11 PM TRH administration on the same day in a sample of 113 consecutively-admitted DSM-IV major depressed inpatients (72 females aged 44.3 +/- 13.0 and 41 males aged 45.7 +/- 10.7) that underwent sleep EEG recordings. 3. A blunted TSH response occurred in 15.9% for 8 AM deltaTSH (maximum increment above baseline at the 8 AM TRH challenge), in 39.8% for 11 PM deltaTSH and in 77% for deltadeltaTSH (difference between 11 PM deltaTSH and 8 AM deltaTSH). A negative correlation between deltadeltaTSH and duration of awakenings after sleep onset, and a shorter sleep onset latency in patients with a blunted 11 PM deltaTSH were found, but these two significant relationships disappeared after controlling for the effects of gender and age. 4. The present findings do not support the hypothesis that, in major depression, HPTA dysfunctioning, as reflected in TSH response to TRH, may be related to sleep EEG disturbances.

Noradrenergic dysfunction and antidepressant treatment response

The purpose of this study was to investigate differences in outcome following treatment with two different antidepressants in depressed patients according to their pretreatment hormonal response to clonidine. In all, 62 drug-free DSM-IV recurrent major depressed patients and 20 normal controls were studied. Patients were subsequently treated for 4 weeks with fluoxetine (n=28), or amitriptyline (n=34), and were then classified as responders or nonresponders according to their final Hamilton depression scale score. Compared to controls, depressed patients showed lower GH response to CLO (DeltaGH) (P<0.0002). One control (5%) and 35 depressed patients (56%) had blunted DeltaGH values. The efficacy of the two antidepressants was not significantly different: 15 patients responded to AMI (44%), seven patients responded to FLUOX (25%) (P>0.15). However, in the subgroup of patients with blunted DeltaGH levels, the rate of responders was higher for AMI (11/21) compared to FLUOX (1/14) treated patients (P<0.01). These results suggest that in depressed patients a blunted GH response to CLO could predict antidepressant response.

Multihormonal responses to clonidine in patients with affective and psychotic symptoms

The neuroendocrine responses to the alpha(2)-adrenoreceptor agonist clonidine (CLO) (0.35 mg if body weight <65 kg or 0.375 mg if body weight> or =65 kg, PO) were studied in a large group of subjects: 134 drug-free inpatients--with either DSM-IV schizophrenia (SCZ, n=31), schizoaffective disorder (SAD, n=16), or major depressive episode (MDE, n=87) - and 22 hospitalized controls (HCs). Comparison with a previous placebo test performed in a subgroup of 92 subjects (46 MDEs, 20 SCZs, 8 SADs, and 18 HCs) showed that CLO induced a significant increase of growth hormone, prolactin (PRL) and thyrotropin (TSH) levels but no significant change in adrenocorticotropin and cortisol release. According to diagnostic categories, we found significantly lower GH stimulation in MDEs and in SADs compared to HCs or to SCZs. In addition, we found significantly lower CLO induced PRL and TSH stimulations in paranoid SCZ patients compared to controls and disorganized SCZ patients. Taken together, these results suggest a hyposensitivity of noradrenergic alpha(2)-receptors in patients with affective symptoms.

Brain pharmacokinetics and tissue distribution in vivo of fluvoxamine and fluoxetine by fluorine magnetic resonance spectroscopy

This investigation of fluvoxamine and fluoxetine-norfluoxetine distributions in vivo at steady-state and of quantitative kinetics in brain and plasma after drug therapy interruption was performed by fluorine nuclear magnetic resonance spectroscopy (19F MRS), spectroscopic imaging (MRSI), and plasma HPLC on 12 subjects treated for depression. MRSI suggests a homogeneous distribution of 19F MRS visible fluvoxamine mainly in brain. Fluvoxamine steady-state brain concentrations (12 +/- 5 microM; n = 13) and brain-to-plasma concentration ratios (10 +/- 2; n = 12) were similar to those of combined fluoxetine-norfluoxetine (CF-norfluoxetine) (13 +/- 6 microM; n = 4 and 10 +/- 6; n = 4). Fluvoxamine brain elimination half-life (79 +/- 24 hours; n = 4) was significantly shorter than that of CF-norfluoxetine (382 +/- 48 hours; n = 2). Fluvoxamine brain-to-plasma-half-life-ratio was 2.2 +/- 0.3 (n = 4), contrarily to CF-norfluoxetine (1.0 +/- 0.3; n = 2). This study shows that quantitative pharmacokinetics in target organs by 19F MRS in vivo should prove useful for understanding and investigating outcome of treatment modifications and side effects.

Serotonergic and noradrenergic function in depression: clinical correlates

The present study was conducted in order to investigate the relationships between central noradrenergic (NA) and serotonergic (5-HT) function and clinical characteristics of a major depressive episode according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. We measured growth hormone response (ΔGH) to clonidine (CLO) (an α2 NA agonist), as an index of central NA function, and prolactin response (APRL) to d-fenfluramine (d-FEN) (a specific 5-HT releaser/uptake inhibitor), as an index of central 5-HT function, in 53 medication-free depressed inpatients. On the basis of their CLO and d-FEN test responses, patients were classified into 4 groups. Group 1 (blunted ΔPRL_d-FEN alone [11 %]) was characterized by a recent violent suicide attempt, a high degree of medical damage, and mild anxiety. Group 2 (blunted ΔGH_CLO alone [32%]) was characterized by an absence of a history of suicide attempt and by severe anxiety. Group 3 (combination of blunted ΔGH_CLO and APRL_d-FEN [18%]) was characterized by a history of suicide attempts, total duration of the illness of over W years, age over 40 years, and more than 3 previous hospitalizations. Group 4 (no abnormality [39%]) had no specific clinical profile. These results suggest that, in depression, specific psychopathological features may be linked to 5-HT and/or NA dysfunction. However, our results also suggest that NA and/or 5-HT dysfunction are less likely to be the primary cause of mood disorders but are more indicative of failure of compensatory mechanisms involved in affective homeostatic processes.

Prolactin response to D-fenfluramine and suicidal behavior in depressed patients

Previous studies of the prolactin response to D-fenfluramine in depressed patients have yielded inconsistent results. This may be because they did not address the question of suicidality. We carried out this study to test the hypothesis that lower prolactin response to D-fenfluramine is more closely associated with suicidal behavior than with depression itself. A D-fenfluramine test was performed in a sample of 18 healthy control subjects and in 85 drug-free inpatients with a DSM-III-R diagnosis of major depressive episode (49 with a history of suicide attempt, 36 without). Depressed inpatients with a history of suicide attempt showed a significantly lower prolactin response to D-fenfluramine compared to depressed inpatients without such a history and compared to control subjects. Healthy control subjects and depressed inpatients without a history of suicide attempt showed comparable levels of prolactin after D-fenfluramine. Time elapsed since suicide attempt did not influence prolactin level (baseline or post-stimulation). Results show that in our depressed drug-free inpatient sample, prolactin response to D-fenfluramine seems to be a marker of suicidality, but not of depression itself. We suggest that it is a trait marker of suicidality.

Dopaminergic function and the cortisol response to dexamethasone in psychotic depression

1. It has been hypothesized that psychotic symptoms in depression may be due to increased dopamine activity secondary to hypothalamic-pituitary-adrenal (HPA) axis overactivity. 2. To test this hypothesis, the authors examined the cortisol response to dexamethasone suppression test (DST, 1 mg orally) and multihormonal responses to apomorphine (APO, 0.75 mg s.c.)--a dopamine agonist--in 150 drug-free hospitalized patients with DSM-IV major depressive episode with psychotic features (MDEP, n=35), major depressive episode without psychotic features (MDE, n=74), or schizophrenia paranoid type (SCZ, n=41), and 27 hospitalized healthy controls (HCs). 3. MDEPs showed increased activity of the HPA system (i.e. higher post-DST cortisol levels) than HCs, SCZs and MDEs. However, there were no differences in adrenocorticotropic hormone (ACTH), cortisol, prolactin and growth hormone (GH) responses to APO between MDEPs and MDEs and HCs. On the other hand, SCZs showed lower APO-induced ACTH stimulation and a higher rate of blunted GH than HCs, MDEs and MDEPs, suggesting a functional alteration of the hypothalamic dopamine receptors in SCZs. 4. In the total sample and in each diagnostic group, DST suppressors and non-suppressors showed no differences in hormonal responses to APO. 5. These results suggest a lack of causal link between HPA axis hyperactivity and dopamine dysregulation. In contrast to schizophrenia, psychotic symptoms in depression seem not to be related to dopamine function dysregulation.

Thyroid axis activity and serotonin function in major depressive episode

Recent studies in depression have reported alterations in both hypothalamic-pituitary-thyroid (HPT) axis activity and serotonin (5-HT) function; however, the functional relationships between the two systems have not been well defined in patients with major depressive episode. Thyrotropin (TSH) response to 0800 and 2300 h protirelin (TRH) challenges, and adrenocorticotropic hormone (ACTH), cortisol, and prolactin (PRL) responses to D-fenfluramine (D-FEN), a specific 5-HT releasing/uptake-inhibiting agent, were examined in 60 drug-free DSM-IV major depressed inpatients and 20 hospitalized controls. Compared with controls, patients showed lower basal serum 2300 h TSH, 2300 h maximum increment in serum TSH above baseline (delta TSH) and difference between 2300 h delta TSH and 0800 h delta TSH (delta delta TSH) levels. The hormonal responses to D-FEN (i.e. delta ACTH, delta cortisol and delta PRL) were interrelated. No significant difference in basal and post-D-FEN ACTH, cortisol or PRL values were found between controls and patients. A negative relationship between hormonal responses to D-FEN and 2300 h delta TSH and delta delta TSH values was observed in the depressed group. When patients were classified on the basis of their delta TSH test status, patients with reduced delta delta TSH values (i.e. with HPT axis abnormality) had hormonal D-FEN responses comparable to those of controls. Patients with normal delta delta TSH values (i.e. without HPT axis abnormality) showed lower ACTH, cortisol and PRL responses to D-FEN than controls and patients with abnormal delta delta TSH values. These results suggest that: (1) pathophysiological mechanisms other than 5-HT dysregulation may be involved in TSH blunting in major depressed patients; (2) 5-HT function is reduced in some depressed patients, especially those without HPT axis abnormality; and (3) HPT dysregulation may be regarded as a compensatory mechanism for diminished central 5-HT activity.

Periodic limb movements and obstructive sleep apneas before and after continuous positive airway pressure treatment

Periodic limb movements during sleep (PLMS) and obstructive sleep apnea syndrome (OSAS) are two common sleep disorders. The similarity in periodicity of periodic limb movements (PLMs) and obstructive sleep apneas (OSAs) led us to hypothesize the existence of a common central generator responsible for the periodicity of both OSAs and PLMs. In order to test this hypothesis, we compared apnea periodicity before continuous positive airway pressure (CPAP) treatment with PLMs periodicity during CPAP treatment in 26 OSA patients, consecutively recorded and treated in our sleep laboratory. The investigation on CPAP was performed twice, once during the initial evaluation and once during a follow-up evaluation after 3 months of home treatment with CPAP. Our results showed that, in this sample, 16 patients out of 26 had an association of OSAS and PLMS, defined as the occurrence of at least 5 PLMs per hour of sleep. The mean apnea interval - measured as the time between the beginning of two successive apneas - was 43.1 s (+/-15.2, SD) and the mean PLM interval - calculated in the same way - was 29.6 s (+/-15.2) during the baseline night, 28.5 s (+/-15.7) during the first CPAP night, and 29.8 s (+/-14.8) during the second CPAP night. Thus, the periodicity of the two phenomena (apneas and PLMs) was different, both before and after CPAP treatment (P< 0.05). When considering the interval between the end of an event (apnea or PLM) and the beginning of the next one the mean apnea interval was 19.5 s (+/-11. 6), and the mean PLM interval was 28.1 s (+/-15.3) during the untreated night, 26.6 s (+/-16) during the first CPAP night and 27.9 s (+/-15) during the second CPAP night. The shortening of apnea intervals with this method of measuring intervals reflects the longer duration of apneas as compared to PLMs. Again the intervals between PLMs were not different between each other but the intervals between apneas were different from the intervals between PLMs (P< 0. 05) These results show that the periodicity of PLMs is different from that of OSAs, suggesting that sleep apneas and PLMs are not generated by a common central generator.

No association between the tyrosine hydroxylase microsatellite marker HUMTH01 and schizophrenia or bipolar I disorder

Linkage and association studies have implicated the involvement of the tyrosine hydroxylase (TH) gene on chromosome 11p15 in schizophrenia and bipolar disorder (BPD). An association of BPD with a polymorphic tetranucleotide repeat, HUMTH01, located in the first intron of the human TH gene has been reported. Subsequently a rare allele, Ep ([TCAT]10) of this microsatellite marker has been found in French and Tunisian schizophrenic patients only. We have genotyped a different sample of unrelated French schizophrenic and BPD patients from Alsace and matched controls for this polymorphic tetranucleotide repeat sequence. The Ep allele was insignificantly more common in controls than in schizophrenic patients, thus not showing a particular association with schizophrenia. In addition, analysis of the segregation of the Ep allele in the family of one of the schizophrenic patients showed no transmission of this allele from the healthy mother to her schizophrenic daughter. Nevertheless, we did observe a non-significant trend towards an association between HUMTH01 allele D ([TCAT]9) and schizophrenia (Fisher's exact test, p = 0.053). No association was apparent between HUMTH01 and BPD Psychiatr Genet.

The human small conductance calcium-regulated potassium channel gene (hSKCa3) contains two CAG repeats in exon 1, is on chromosome 1q21.3, and shows a possible association with schizophrenia

Mutations in various ion channel genes are responsible for neuromuscular and other neurological disorders. We have previously identified the human small conductance calcium-activated potassium channel gene (hSKCa3) which has two tandemly arranged CAG repeats in its 5' region. Here we have isolated the first genomic clones containing the gene and have shown that both repeats are in exon 1. Homology to the previously localized sequence tagged site G16005 indicated that the gene may be on chromosome 22q, however using polymerase chain reaction amplification of somatic cell hybrid DNA and fluorescence in situ hybridization of two P1 artificial chromosome clones, we physically localized the gene to chromosome 1q21.3. We previously found an association between the highly polymorphic second (more 3') CAG repeat and schizophrenia in 98 patients and 117 controls. We have now genotyped an additional 19 patients with schizophrenia and have performed statistical analyses on the entire group of patients and controls to investigate the possible effect of age of onset, family history, and gender of the patients on the observed association. None of these factors were found to influence the results. Both CAG repeats have been typed in 86 bipolar I disorder patients, and no significant difference in allele distribution was observed between our bipolar disorder patients and controls.

Central effects of acamprosate: part 2. Acamprosate modifies the brain in-vivo proton magnetic resonance spectrum in healthy young male volunteers

Although acamprosate is a drug which is successfully used for therapy in maintaining alcohol abstinence following alcohol withdrawal in chronic alcoholism, little is understood about its mechanism of action in the central nervous system. Our objective was to assess the effects of acamprosate on the central nervous system in healthy subjects by dynamic proton magnetic resonance spectroscopy (MRS) measurements localized in brain tissue in vivo. Recordings were performed after intravenous administration of acamprosate or placebo to eight healthy male volunteers participating in a double-blind, randomized, cross-over, placebo-controlled study. The data were acquired using a spin-echo volume selective localized spectroscopy scheme on a 3-T whole body MRS system. Spectra obtained at baseline and at 20-min time intervals after the beginning of drug infusion were analyzed on the basis of five non-overlapping spectral integration regions. In the acamprosate-treated group, the median integral values in the regions for which N-acetylaspartate and glutamate are the main signal contributors showed decreases relative to placebo 20 min after the infusion began. Results suggest a central glutamatergic effect of acamprosate consistent with cerebral microdialysis glutamate measurements in vivo obtained from alcoholized rats treated with acamprosate (Part 1 of this study). This study is to our knowledge the first one describing a central effect of acamprosate in humans by MRS.

Central effects of acamprosate: part 1. Acamprosate blocks the glutamate increase in the nucleus accumbens microdialysate in ethanol withdrawn rats

One of the known behavioral actions of acamprosate is to decrease hypermotility during alcohol withdrawal. However, the mechanism of this effect remains unclear. In this study, the concentrations of excitatory and inhibitory amino acids were assayed by the microdialysis technique with OPA/BME precolumn derivatization and electrochemical detection in the nucleus accumbens of male Wistar rats which were either alcoholized by ethanol inhalation or simultaneously alcoholized and treated orally by acamprosate (400 mg/kg/day) for 4 weeks. Without treatment, extracellular glutamate increased during the withdrawal phase, while other amino acids tested (aspartate, arginine, taurine, alanine and GABA) remained stable. In contrast, the alcoholized rats treated with acamprosate failed to present the increase in glutamate during ethanol withdrawal, while other amino acids tested also remained stable. The observed glutamate increase could be responsible for the hyperexcitability observed during episodes of ethanol withdrawal. These results suggest that acamprosate is able to reduce the ethanol withdrawal syndrome by reducing the concentration of glutamate in the nucleus accumbens.

Serotonin transporter (5-HTT) gene polymorphisms are not associated with susceptibility to mood disorders

In a population-based association study, we tested the hypothesis that allelic variants of the human serotonin transporter (5-HTT) gene confer susceptibility to mood disorders. Both a biallelic repeat polymorphism in the 5' promotor region that differentially modulates gene expression and a second intron variable-number-tandem-repeat (VNTR) marker were genotyped in 294 controls and 115 patients with mood disorders. Subjects were of West European descent and included 36 patients with major depressive disorder (MDD) and 79 patients with bipolar I disorder (BD). No significant differences in genotype or allele frequencies were found at either locus between controls and combined patients, nor between controls and MDD or BD patients separately. Thus, our data do not support the association between depressive disorder and a nine-repeat allelic variant of the 5-HTT VNTR marker recently reported by Ogilvie et al. (Lancet 347:731-733, 1996). More importantly, no association between alleles conveying functional differences in 5-HTT gene expression and MDD or BD could be found. Taken together, our data suggest that the 5-HTT gene is not commonly involved in the susceptibility to mood disorders.

Changes in EEG power density during sleep laboratory adaptation

First- and second-night effects on the electroencephalogram (EEG) were investigated by means of polygraphic sleep recordings and all-night spectral analysis. Eighteen normal subjects were studied for three consecutive nights in a hospital sleep laboratory. Visual sleep scoring showed that there was a first-night effect in normal subjects similar to that reported previously [increased wakefulness; decreased total sleep time, sleep efficiency, and rapid eye movement (REM) sleep]. Spectral analysis of the sleep EEG revealed important changes, most of which occurred in REM sleep. Increased delta, theta, and beta1 power densities accompanied by decreased mean frequency were seen in REM sleep in the second night. On the basis of REM sleep deprivation results previously published, our data suggest that the second night could be affected by partial REM sleep deprivation that occurred in the first night. Delta and theta power density values decreased in the first non-rapid eye movement episode of nights 1 and 2; this could result from increased REM sleep pressure. The overall consistency of spectral data in the first and second night with REM sleep findings derived from visual scoring in the first night lends further support to this hypothesis. The sleep disturbance experienced during the first night in a sleep laboratory may be a useful and valid model of transient insomnia. Therefore, we conclude that data from all nights recorded should be included in assessing a subject's sleep.

Temporal relationships between pulsatile cortisol secretion and electroencephalographic activity during sleep in man

A temporal link between slow wave sleep and low or decreasing cortisol release has been previously demonstrated. This relationship was re-evaluated in 15 healthy male subjects using spectral analysis of their sleep electroencephalogram (EEG). EEG activity in the delta, theta, alpha and beta bands was cross-correlated with cortisol secretory rates at 10-min intervals. For the period of pulsatile cortisol secretion, an inverse relationship was found with the delta band with an average cross-correlation coefficient of -0.505 (P < 0.0001). Variations in cortisol secretory rates coincided with or anticipated opposite variations in delta wave activity by 10 or 20 min. A significant positive correlation was found with theta activity, but alpha and beta bands did not elicit any systematic association with cortisol profiles. These results demonstrate a temporal association between cortisol secretory pulses and delta wave activity in man, suggesting the existence of a central control common to both variables.

Analysis of the CAG repeats in the SCA1 and B37 genes in schizophrenic and bipolar I disorder patients: tentative association between B37 and schizophrenia

We have genotyped unrelated French Alsatian schizophrenic and bipolar I disorder (BPD) patients and matched controls for the polymorphic CAG repeats within the genes for spinocerebellar ataxia type 1 (SCA1) and dentatorubral-pallidoluysian atrophy (B37), in order to test their possible involvement in these disorders. No alleles with abnormally expanded repeats were found in either gene in patients and controls. Differences in allele and genotype frequencies for the SCA1 CAG repeat between patients and controls were not significant, thus providing no support for its role as a possible positional candidate gene for schizophrenia and BPD in our patients. Chi square testing revealed a significant result (P = 0.019) for an association between the B37 CAG repeat on chromosome 12p and schizophrenia. This result was more significant when only schizophrenics with a positive family history were compared with controls (P = 0.0001). The frequencies of alleles with 14, 12, and 15 CAG repeats differed the most, respectively, between schizophrenics and controls. When choosing the median of the B37 allele distribution (15 CAG repeats) as a threshold, there were significantly more controls than schizophrenics in the group with longer alleles (15 or more repeats) and more schizophrenics with shorter alleles (P = 0.002 by Fisher exact test). No particular genotype was associated with schizophrenia. This result possibly indicates linkage disequilibrium with another locus on chromosome 12p and therefore deserves further attention. No association was found between the B37 CAG repeat and patients with BPD.

HPA axis dysfunction in depression: correlation with monoamine system abnormalities

Abnormality of the hypothalamic-pituitary-adrenal (HPA) axis has been one of the most consistently demonstrated biological markers of depressive disorder. It has also been proposed that abnormality of monoamine function plays a role in the pathogenesis of the disorder. In order to examine the interrelationships of the HPA axis with the dopaminergic, noradrenergic, and serotoninergic systems, we studied, in 52 medication-free inpatients with DSM-IV nonpsychotic major depressive disorder, the relationship between dexamethasone suppression test (DST) status and a series of multihormonal responses to apomorphine (APO), clonidine (CLO), and D-fenfluramine (FEN) tests. DST nonsuppressors did not present any difference compared with suppressors in growth hormone (GH) and cortisol stimulation by APO suggesting that a chronic elevation of cortisol did not lead to an alteration of dopaminergic activity in this population of nonpsychotic depressed inpatients. Cortisol and prolactin responses to FEN were comparable in nonsuppressors and in suppressors. In contrast, GH response to CLO was lower in DST nonsuppressors than in suppressors (p < .03), suggesting that the HPA abnormality indicated by a positive DST may be related to alpha 2-adrenoreceptor dysfunction.

A quantitative evaluation of the relationships between growth hormone secretion and delta wave electroencephalographic activity during normal sleep and after enrichment in delta waves

The existence of a relationship between growth hormone (GH) release and slow-wave sleep (SWS), often studied in the past using conventional scoring of sleep stages, remains controversial. In the present study, this relationship was reevaluated by spectral analysis of the sleep electroencephalogram (EEG) and deconvolution analysis of the plasma GH concentrations during normal nocturnal sleep and after enrichment in SWS by means of ritanserin, a selective 5-HT2 receptor antagonist. Eight healthy male subjects each participated in two randomized night studies after having received either a placebo or a 5-mg dose of ritanserin. They were subjected to 8 hours of polysomnography, including spectral analysis of the sleep EEG. Plasma GH levels were measured at 10-minute intervals. The mean delta absolute power and the mean GH secretory rates were significantly higher under ritanserin than under placebo for the first 3 hours after sleep onset (+24% and +29%, respectively). Their nocturnal profiles were significantly and positively correlated in all subjects (average r = 0.710 under placebo, 0.567 under ritanserin; p < 0.0001 in both cases). GH secretory pulses were found to be coincident with delta activity peaks in both directions. The amount of GH secreted during significant GH pulses was correlated with the amount of concomitant delta wave activity (r = 0.803 under placebo, r = 0.764 under ritanserin, p < 0.0001). Similarly, the amount of delta wave activity found during delta wave peaks was correlated with the amount of GH secreted concomitantly (r = 0.715 under placebo, r = 0.723 under ritanserin: p < 0.0001). These results demonstrate a close temporal and quantitative relationship between GH secretion and delta wave activity, which may be evidence of common stimulatory mechanisms.

5-HT2 receptors are partially involved in the relationship between renin release and delta relative power

A strong relationship was previously described between the nocturnal oscillations of plasma renin activity (PRA) and the sleep cycles, with levels of PRA that increase during non rapid eye movement sleep and decrease during rapid eye movement sleep. This study was designed to determine whether ritanserin, a 5-hydroxytryptamine-2 (5-HT2) receptor antagonist known to increase slow wave sleep both in human and in animals and to decrease plasma renin activity response to serotonergic stimulation in the rat, would uncouple this relationship. Eight subjects underwent two randomized night studies after having received either placebo or 5 mg ritanserin administered in the morning. They were subjected to 8 hour polysomnography, including spectral analysis of the electroencephalogram and to continuous blood sampling. Blood was sampled from 2300 to 700h every 10 min and plasma renin activity (PRA) was measured by radioimmunoassay of angiotensin 1. The nocturnal profiles were analysed using the pulse detection program ULTRA. Ritanserin produced the expected increase in slow wave sleep (SWS) duration (132 +/- 10 min under ritanserin vs 72 +/- 9 min under placebo; p < 0.001) and a significant increase in delta relative power (69 +/- 2% under ritanserin vs 60 +/- 2% under placebo; p < 0.01). The mean overnight PRA levels had a tendency to decrease under ritanserin (1.66 +/- 0.34 ngAngl/ml per h under ritanserin vs 1.48 +/- 0.31 ngAngl/ml per h under placebo; p = 0.08). Individual PRA oscillations were preserved and remained strongly associated with delta power oscillations. PRA peak levels were similar in both experimental conditions, but the absolute amplitude of the oscillations was decreased under ritanserin (1.50 +/- 0.36 ngAngl/ml per h vs 1.04 +/- 0.14 ngAngl/ml per h; p < 0.05). These results demonstrate that ritanserin, at a dose that augments delta power, only weakly affects renin release, which suggests that 5-HT2 receptors are only partially involved in the processes coupling renin release and SWS and that other mechanisms probably control the sleep-associated variations in PRA.

Effect of antidepressant medication on morning and evening thyroid function tests during a major depressive episode

BACKGROUND

This study sought to determine whether changes in thyroid function that may occur during antidepressant treatment are related to a direct effect of the drug on the thyroid axis or to a change in clinical state.

METHODS

Morning and evening thyroid function was evaluated in 30 euthyroid inpatients who met DSM-IV criteria for major depressive episode, by determination of free triiodothyronine, free thyroxine, and thyrotropin levels before and after 8 AM and 11 PM protirelin challenges (200 micrograms intravenously), on the same day. Results at baseline were compared with those after 1 month of antidepressant treatment with either amitriptyline hydrochloride, fluoxetine hydrochloride, or toloxatone.

RESULTS

Clinical efficacy and effects on thyroid function did not differ across the 3 antidepressant drugs. Compared with pretreatment values, significant reductions in basal serum 8 AM free thyroxine, 11 PM free thyroxine, and 8 AM free triiodothyronine levels and increases in 11 PM maximum increment in plasma thyrotropin level and the difference between 11 PM and 8 AM maximum increment in plasma thyrotropin values were observed in responders (n = 11) but not in partial responders (n = 6) or nonresponders (n = 13). Moreover, nonresponders exhibited lower pretreatment 11 PM thyrotropin values (basal and maximal increment above basal) than responders.

CONCLUSIONS

The results suggest that (1) changes in thyroid function are related to clinical recovery rather than to a direct effect of the antidepressant drug and (2) patients with the lowest pretreatment evening thyrotropin secretion have the lowest rate of antidepressant response, and this may contribute to treatment resistance.

Low-dimensional dynamic self-organization in delta-sleep: effect of partial sleep deprivation

Studies on extended data including 37 electroencephalographic (EEC) records of delta-sleep, each 10(3) s long (six subjects: up to seven nights per subject, comprising normal sleep, partial deprivation and recovery), confirmed earlier conclusions that rare episodes of low-dimensional dynamic self-organization, with life-times between 10 and 20 s, are present in stage 4 sleep. Particular care was taken of the Theiler correction which, in some delta-sleep signals, required the deletion of trajectory points covering nearly one pseudo-period. The percentage of segments showing an episode, i.e. the attractor probability, decreased with a change in sleep conditions either deprivation or recovery prior to the next deprivation. Repetition of deprivation over three nights resulted in an adaptation process, manifested by an increase in attractor probability. After the sharp decrease in probability observed when recovery was established prior to the next deprivation, and on return to normal conditions of sleep at 2200 hours, the probability was immediately close to that observed in normal baseline sleep conditions free of any interference. The observation of a definite effect of sleep deprivation and recovery upon the number of stage 4 attractors observed provides a line of approach to the physiological significance of the probability of such attractors.

Growth hormone response to clonidine and the cortisol response to dexamethasone in depressive patients

The dexamethasone suppression test (DST) and the clonidine stimulation test (CST) were studied in 47 depressed patients. Issues addressed included (1) the usefulness of both tests as markers of major depression; (2) the relationship between the two tests and the pathophysiology underlying this relationship; and (3) the psychopathological correlates of both tests. The widely reported link between abnormal DST results and melancholic depression was confirmed. The DST and the CST showed extensive overlap, suggesting a relationship in major depression between the biological abnormalities indexed by each test (i.e., hypothalamic-pituitary-adrenal axis and noradrenergic system). Finally, the psychopathological correlates of various subgroups categorized on the basis of test responses (e.g., normal test results, blunted CST results, and both abnormal DST and CST results) confirmed significant differences between groups on two items of the Hamilton Rating Scale for Depression: psychic anxiety and somatic anxiety. The results suggest that particular patterns of neuroendocrine abnormalities may be associated with particular profiles of depressive symptomatology.

Dopamine D3 receptor gene: organization, transcript variants, and polymorphism associated with schizophrenia

DNA fragments from a genomic library were used to establish the partial structure of the human dopamine D3 receptor gene (DRD3). Its coding sequence contains 6 exons and stretches over 40,000 base pairs. The complete DRD3 transcript and three shorter variants, in which the second and/or third exon are deleted, were detected in similar proportions in brains from four controls and three psychiatric patients. The Msp I polymorphism was localized in the fifth intron of the gene, 40,000 base pairs downstream the Bal I polymorphism and a PCR-based method was developed for genotyping this polymorphism. The distribution of the Msp I and Bal I genotypes were not independent in 297 individuals (chi 2 = 10.5, df = 4, P = 0.03), but only a weak association was found between allele 1 of the Bal I polymorphism and allele 2 of the Msp I polymorphism (chi 2 = 3.99, df = 1, P = 0.04). The previously reported association between homozygosity at both alleles of the Bal I polymorphism and schizophrenia was presently maintained in an extended sample, comprising 119 DSM-III-R chronic schizophrenics and 85 controls (chi 2 = 5.3, df = 1, P = 0.02) and found more important in mal than in females. The presence of the Bal I allele 2 is associated with an early age at onset, particularly in males (df = 35, t value = 2.6, P = 0.014). In the same sample, allelic frequencies, genotype counts, and proportion of homozygotes for the Msp I polymorphism did not differ between schizophrenics and controls (chi 2 = 0.06, df = 1, P = 0.80, chi 2 = 0.22, df = 1, P = 0.90 and chi 2 = 0.16, df = 1, P = 0.69, respectively). The large distance of the Msp I polymorphism from the Bal I polymorphism and its localization in the 3' part of the gene may explain the discrepant results obtained with the two polymorphisms.

Pharmacoelectroencephalographic profile of befloxatone, a new reversible MAO-A inhibitor, in healthy subjects

The pharmaco-EEG profile and the effects on P300 and CNV of befloxatone, a new selective and reversible MAO-A inhibitor, were assessed in a randomized, double-blind, placebo-controlled, 4-way crossover study. Twelve healthy young male volunteers were administered single doses of 2.5, 10 and 20 mg befloxatone and placebo separated by a 1-week washout. The EEG data were recorded before and at least 6 h after drug administration, by means of 28 leads allowing topographical analysis of the results. MAO inhibition, subjective effects and safety variables were also investigated. Statistical analysis was performed by means of the SDT method. Befloxatone induced dose-related EEG changes which occurred rapidly, peaked between 0.5 and 2 h and lasted at least until 6 h after drug administration. The EEG changes were characterized by an increase in absolute and/or relative alpha power, mainly alpha 1, after the 3 doses and a theta power increase after 10 and 20 mg only. These changes occurred mainly over the centroparietotemporal areas. Concerning the event-related potential, P300 latency of the auditory evoked potentials did not change. The P300 and CNV mean topographic amplitudes were decreased, between 0.5 and 2 h, after the two lowest doses for the P300 and the 3 doses for the CNV. After administration of 2.5, 10 and 20 mg, MAO inhibitions was shown by respectively 38, 76 and 81% reduction in plasma free 3, 4-dihydroxyphenylglycol reached after 2-4 h. Such a pharmaco-EEG profile, occurring at doses inducing MAO-A inhibition, is similar to those already described with nonsedative antidepressants.

BalI and MspI polymorphisms of the dopamine D3 receptor gene in African Blacks and Caucasians

An exonic BalI polymorphism and an intronic MspI polymorphism of the dopamine D3 gene were genotyped in 101 Caucasians from the Alsace and in 56 people from the Congo. This is the first study of the BalI polymorphism in sub-Saharan Africa and the first population study of the MspI site. BalI allele 1 was rare in the Congo (0.12) whereas it is the most frequent allele in all studies in Europe and Asia. MspI allele 1 was also significantly less frequent in the Congolese (0.24) than in Caucasians (0.52). D3 gene alleles show different frequencies in sub-Saharan Africa and may be useful for population studies.

Sleep stage scoring using the neural network model: comparison between visual and automatic analysis in normal subjects and patients

In this paper, we compare and analyze the results from automatic analysis and visual scoring of nocturnal sleep recordings. The validation is based on a sleep recording set of 60 subjects (33 males and 27 females), consisting of three groups: 20 normal controls subjects, 20 depressed patients and 20 insomniac patients treated with a benzodiazepine. The inter-expert variability estimated from these 60 recordings (61,949 epochs) indicated an average agreement rate of 87.5% between two experts on the basis of 30-second epochs. The automatic scoring system, compared in the same way with one expert, achieved an average agreement rate of 82.3%, without expert supervision. By adding expert supervision for ambiguous and unknown epochs, detected by computation of an uncertainty index and unknown rejection, the automatic/expert agreement grew from 82.3% to 90%, with supervision over only 20% of the night. Bearing in mind the composition and the size of the test sample, the automated sleep staging system achieved a satisfactory performance level and may be considered a useful alternative to visual sleep stage scoring for large-scale investigations of human sleep.

Temporal link between plasma thyrotropin levels and electroencephalographic activity in man

Plasma thyrotropin (TSH) levels have been previously shown to be associated with the internal sleep structure determined by conventional scoring of sleep stages. This temporal relationship was re-evaluated using spectral analysis of the sleep electroencephalogram (EEG). Eight healthy male subjects underwent two randomized night studies after having received either placebo or 5 mg ritanserin, a selective 5-HT2 receptor antagonist known to increase slow-wave sleep. Delta relative power and TSH levels, determined at 10 min intervals, were found to be inversely related with an average cross-correlation coefficient highly significant (P < 0.0001) in both experimental conditions. Alpha slow-wave index, an estimator of awakenings, and TSH pulses exhibited a significant temporal association in both conditions. These results demonstrate that TSH fluctuations are linked to the sleep EEG activity in man.

Slow wave electroencephalic activity parallels renin oscillations during sleep in humans

Previous studies have demonstrated that the nocturnal oscillations of plasma renin activity (PRA) exactly reflect rapid eye movement (REM) non-REM (NREM) sleep alternation with levels of PRA that increase during NREM sleep and decrease during REM sleep. These studies were based exclusively on conventional scoring of sleep stages. In the present study, we used spectral analysis of the sleep EEG to determine the variations in the different EEG frequency bands, together with PRA profiles. Eight male volunteers participated in a 1 night study. They were subjected to 8 h polysomnography including spectral analysis of the EEG, and to blood sampling every 10 min. Delta relative power and Sleep Intensity Index and PRA oscillations ran parallel in all individuals. An increase in slow waves was associated with an increase in PRA, whereas a decrease was associated with a decrease in PRA. Cross-correlation coefficients were significant and ranged between 0.34 and 0.74. Conversely, theta, alpha and beta bands and the EEG mean frequency were inversely proportional to PRA, with lower cross-correlation coefficients. These results may give further support to the hypothesis of a common mechanism controlling both SWA and renin release from the kidney.

Temporal relationship between prolactin secretion and slow-wave electroencephalic activity during sleep

It is well established that plasma prolactin (PRL) concentrations exhibit a sleep-dependent pattern, with the highest levels occurring during sleep and the lowest during waking. Still, controversy exists concerning an association between rapid eye movement (REM) and non-REM sleep cycles and plasma PRL pulses. These studies were all based on conventional scoring of sleep stages. In the present study, plasma PRL concentrations were analyzed at 10-minute intervals in 10 subjects during the night when sleeping. PRL secretory rates were calculated by a deconvolution procedure. Spectral parameters of sleep electroencephalographic (EEG) recordings were analyzed together with PRL secretion using cross-correlation. Slow-wave activity of the EEG and PRL secretion ran parallel in all individuals. Conversely, alpha and beta bands and the EEG mean frequency were inversely proportional to PRL secretion. In 9 of the 10 subjects studied, PRL secretion was concomitant with delta waves or lagged behind by 10-20 minutes, depending on subjects, with maximum cross-correlation coefficients ranging between 0.40 and 0.67. This temporal relationship between PRL secretion and delta waves was further assessed by a pulse-by-pulse analysis based on the calculation of probability levels after computer simulations. Nine of the 10 subjects displayed significant concomitance between delta wave activity and PRL secretory oscillations. These results demonstrate that PRL secretion during sleep is coupled to delta waves in young healthy men.

All-night EEG spectral analysis as a tool for the prediction of clinical response to antidepressant treatment

Earlier investigations have suggested that variables derived from quantified electroencephalographic (EEG) sleep analysis might predict good clinical response in an early phase of antidepressant treatment. In this report we evaluate the predictive value of all-night sleep EEG spectral analysis during the washout period before treatment. We compared the spectral EEG sleep profiles of major depressed inpatients divided into two groups according to an improvement > or = 50% on the Hamilton Rating Scale for Depression. Findings in this population demonstrate the presence of specific characteristics of the responder group compared with the nonresponder group. Delta band relative power was increased in the former group, while theta, alpha, and beta relative power were decreased. All the bands showed decrease in absolute power in the responder group. These results can be interpreted as enhanced sleep intensity in the responder group. All-night sleep EEG spectral variables are valid baseline markers of the functional differences between treatment responders and nonresponders and thus might permit prediction of clinical outcome.

First-night effect in normal subjects and psychiatric inpatients

The goal of the present study was to evaluate the first-night effect in psychiatric inpatients using large subject samples (n > 30) in order to obtain a good statistical evaluation. Thirty-two normal subjects and 94 psychiatric inpatients (38 depressives and 56 insomniacs) were studied for three consecutive nights in the hospital sleep laboratory. Our results showed clearly that there was a first-night effect in normal subjects, similar to that reported in previously published data, characterized by a longer rapid eye movement (REM) sleep latency (p < 0.05), increased wakefulness (p < 0.01) and total sleep time (p < 0.02) and a decreased sleep efficiency (p < 0.01). REM sleep latency and stage REM in the first third of the night were still altered in the second night. Both clinical groups had a less marked first-night effect than normal subjects, showing alterations only observed in REM sleep (p < 0.01) (decreased REM sleep, longer REM sleep latency, increased REM sleep gravity center). However, the first-night effect was more pronounced in insomniacs than in depressed patients. No statistical differences between the second and third nights' recordings were found in sleep parameters. It is suggested that first-night data should not be simply discarded but could be used in subsequent analyses.

Multihormonal responses to apomorphine in mental illness

The neuroendocrine responses to subcutaneous (SC) administration of the dopamine (DA) agonist apomorphine (APO) hydrochloride (0.75 mg) were studied in a large group of subjects: 110 drug-free inpatients with either DSM-III-R schizophrenia (SCZ, n = 46), schizoaffective disorder (SAD, n = 14), or major depressive episode (MDE, n = 50), plus 18 hospitalized controls. Compared to a saline test, APO induced a significant increase of growth hormone (GH), adrenocorticotropin (ACTH), and cortisol (COR) release and a decrease in prolactin (PRL) secretion. No change in thyrotropin (TSH) levels was observed. In the total sample the extents of ACTH, COR and GH responses were correlated, but in the group of 88 subjects who exhibit a normal GH stimulation this correlation disappeared. This discrepancy suggests that APO-induced ACTH and COR stimulation may be mediated by pathways different from those mediating GH stimulation. According to diagnostical categories, we found significant lower ACTH and COR stimulation in the schizophrenic group and in patients with SAD, compared with that among controls or depressed patients. We found also a significant difference between subgroups of schizophrenic patients. These results agree with the hypothesis that different aspects of psychosis might involve different subtypes of DA-receptors with different localizations and sensitivities.

An architecture for EEG signal processing and interpretation during sleep (ESPIS)

The project's aim is to develop a dedicated workstation in order to process multiple channels of electrophysiological signals in real-time during sleep. In ESPIS we are aiming to define both an architecture and an environment for EEG signal interpretation in medicine based on computer science gold standards (Unix, XWindow, Motif). Signal processing and pattern recognition analysis are provided by parallel processing on a specific developed acquisition architecture (DSP) based on transputers. The main result is a high performance prototype demonstrating signal interpretation during sleep which has already been tested in a medical environment. The overall specifications allow this biomedical device to be extended to other types of medical signals.

Influence of thyroid hormones on morning and evening TSH response to TRH in major depression

The serum levels of thyroid hormones and thyrotropin (TSH) were evaluated before and after 8 PM and 11 PM thyrotropin-releasing hormone (TRH) challenges, on the same day, in 41 drug-free DSM-III-R euthyroid major depressed inpatients and 16 hospitalized controls. Depressed patients exhibited elevated circulating concentrations of thyroid hormones, which were associated with and may have contributed to the blunted TSH response to TRH. This was confirmed by: (a) higher basal levels (albeit not always statistically significant) of free triiodothyronine (FT3B) and free thyroxine (FT4B) at 8 AM and 11 PM in the depressed patient population compared with the controls; (b) lower basal levels of TSH in the depressed subjects (even though this was only statistically significant at the 11 PM sampling) compared with the controls; (c) blunted TSH response to TRH (delta TSH) in the depressed group (although this was only statistically significant at 11 PM) and blunted delta delta TSH values (differences between 11 PM-delta TSH and 8 AM-delta TSH).

Statistical Decision Tree: a tool for studying pharmaco-EEG effects of CNS-active drugs

Quantitative pharmaco-EEG has become a useful technique for determining pharmacodynamic parameters after CNS-active drug administration. Nevertheless, one of the most important problems faced by practitioners of pharmaco-EEG is the difficulty in evaluating drug-specific effects. In this article, a methodology for comparing two time sequences of pharmacodynamic measurements, the Statistical Decision Tree (SDT), is proposed. This methodology, based on one- and multi-dimensional Wilcoxon signed-rank tests on EEG variables, takes into account vigilance fluctuations and placebo effects in order to pick out effects specifically due to the drug.

Neural network model: application to automatic analysis of human sleep

We describe an approach to automatic all-night sleep analysis based on neural network models and simulated on a digital computer. First, automatic sleep stage scoring was performed using a multilayer feedforward network. Second, supervision of the automatic decision was achieved using ambiguity rejection and artifact rejection. Then, numerical analysis of sleep was carried out using all-night spectral analysis for the background activity of the EEG and sleep pattern detectors for the transient activity. Computerized analysis of sleep recordings may be considered as an essential tool to describe the sleep process and to reflect the dynamical organization of human sleep.