Sleep effects of a 24-h versus a 16-h nicotine patch: A polysomnographic study during smoking cessation

BACKGROUND AND PURPOSE

Sleep disturbance is a common symptom of tobacco withdrawal and might contribute to early relapse vulnerability in abstinent smokers. This study was designed to compare the effects on sleep of nicotine patches applied either for 24 h (Nicopatch) or 16 h (Nicorette).

PATIENTS AND METHODS

During a short smoking cessation period (48 h), this open-label, randomised, two-period crossover study compared the effects on sleep of the two nicotine patches in 20 heavy smokers (9 women, 11 men). During each period, polysomnographic recordings were performed from 12 pm to 7 am for two consecutive nights (baseline and treatment nights). Smoking cessation started from 8 pm the day of the baseline sleep recordings, and treatments were applied around 8 am the following morning.

RESULTS

Compared to the 16-h nicotine patch, smokers who received the 24-h nicotine patch experienced significantly less microarousals, a greater proportion of slow wave sleep, a higher REM density and higher rapid eye movement (REM) beta activities.

CONCLUSIONS

The results of this study suggest that a 24-h nicotine patch is more efficient than a 16-h nicotine patch to alleviate tobacco withdrawal-induced sleep disturbances.

Sleep disturbances, psychiatric disorders, and psychotropic drugs

Brain neurotransmitter dysfunctions involved in the pathophysiological processes of psychiatric disorders are likely to be reflected by concomitant alterations in sleep continuity and architecture. Since the corrective effects of psychotropic drugs on dysfunctional neurotransmission systems can be evidenced through polysomnographic recordings, one may consider sleep as a kind of “window” on the neurobiology of psychiatric disorders. During the last 10 years, major breakthroughs in our understanding of sleep-wake mechanisms have provided some indications on how psychotropic drugs could influence the sleep-wake cycle. In this review, recent inroads into the understanding of sleep regulatory neural mechanisms are introduced and discussed in terms of the effects of psychotropic drugs. The relationship between the patho-physiological process of a disease, its consequence on sleep, and the corrective effect of a psychotropic drug are exemplified by two psychopathological states: substance withdrawal and major depression. One may conclude that polysomnographic recordings are a unique noninvasive tool to analyze brain functioning, and are particularly well suited to evaluating the objective effects of new psychotropic drugs.

Surrogate outcomes in neurology, psychiatry, and psychopharmacology

A surrogate outcome can be defined as an outcome that can be observed sooner, at lower cost, or less invasively than the true outcome, and that enables valid inferences about the effect of intervention on the true outcome. There is increasing interest in the use of surrogate outcomes of treatment efficacy measurement in investigational drug trials. However, the significance of surrogate markers of treatment outcome in neurology and psychiatry has not yet been sufficiently demonstrated. Few such markers have been adequately "validated, " that is, shown to predict the effect of the treatment on the clinical outcome of interest. In this article, evidence that would support the validation of such markers is discussed. Biomarkers used during early clinical development programs of new psychotropic compounds are considered in the contexts of Parkinson's disease, affective disorder, and schizophrenia. The particular case of neuroprotective trials is exemplified by Parkinson's disease, where a biomarker substituting for a clinical measure of progression could be considered as a surrogate treatment outcome.

Suicide attempts and family history of suicide in three psychiatric populations

The influence of a family history of suicide on suicide attempt rate and characteristics in depression, schizophrenia, and opioid dependence was examined. One hundred sixty inpatients with unipolar depression, 160 inpatients with schizophrenia, and 160 opioid-dependent patients were interviewed. Overall, a family history of suicide was associated with a higher risk for suicide attempt, with high-lethality method, with repeated attempts, and with number of attempts, while the interaction between family history and diagnostic group was not significant. Thus, a positive family history of suicide was a risk factor for several suicide attempt characteristics independent of psychiatric diagnosis.

Next-day residual effects of hypnotics in DSM-IV primary insomnia: a driving simulator study with simultaneous electroencephalogram monitoring

RATIONALE

Most studies that investigated the next-day residual effects of hypnotic drugs on daytime driving performances were performed on healthy subjects and after a single drug administration.

OBJECTIVES

In the present study, we further examine whether the results of these studies could be generalised to insomniac patients and after repeated drug administration.

METHOD

Single and repeated (7 day) doses of zolpidem (10 mg), zopiclone (7.5 mg), lormetazepam (1 mg) or placebo were administered at bedtime in a crossover design to 23 patients (9 men and 14 women aged 38.8+/-2.0 years) with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) primary insomnia. Driving tests were performed 9-11 h post-dose.

RESULTS

Results showed that treatment effects were evidenced for subjective sleep, for driving abilities, and for electroencephalogram (EEG) recorded before (resting EEG) and during the driving simulation test (driving EEG). Compared to placebo, zopiclone increased the number of collisions and lormetazepam increased deviation from speed limit and deviation from absolute speed, whereas zolpidem did not differentiate from placebo on these analyses. EEG recordings showed that in contrast to zolpidem, lormetazepam and zopiclone induced typical benzodiazepine-like alterations, suggesting that next-day poor driving performance could relate to a prolonged central nervous system effect of these two hypnotics.

CONCLUSION

The present results corroborate studies on healthy volunteers showing that residual effects of hypnotics increase with their half-lives. The results further suggest that drugs preserving physiological EEG rhythms before and during the driving simulation test 9-11 h post-dose, such as zolpidem, do not influence next-day driving abilities.

Inverse association between Slow Wave Activity per cycle and the number of ultradian sleep cycles per night in healthy humans

OBJECTIVE

Comparisons of sleep Slow Wave Activity (SWA) during successive sleep cycles rely on the assumption that SWA in a given cycle is independent of the number of ultradian cycles present in a night. This assumption was evaluated here.

METHODS

Twenty-six healthy controls with no medical, sleep or psychiatric disorders were selected among 84 candidates and their sleep was recorded at home across 2 consecutive nights after two habituation nights.

RESULTS

In comparison with nights with less cycles, nights with more cycles showed significantly more REMS but not more NREMS. No correlation was found between the number of cycles and the integrated SWA per night (epochs visually scored as NREMS). However, inverse correlations were found between the number of cycles and the SWA per cycle. This was significant on both nights in Cycle 1 and strong trends were found for the two subsequent cycles on Night 2. Comparable results were found after removal of nights containing suspected Skipped First REMS episodes.

CONCLUSIONS

The SWA in a cycle was found to be inversely correlated to the number of cycles in the first 3 cycles in at least one of the two analyzed nights.

SIGNIFICANCE

Differences in the number of cycles per night are a potential bias in the comparisons of SWA per cycles.

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.

Periodic limb movements and sleepiness in obstructive sleep apnea patients

BACKGROUND AND PURPOSE

The aim of this study was to assess the possibility that periodic limb movements during sleep (PLMS) could play an additive role in the sleepiness associated with obstructive sleep apnea syndrome (OSAS) before treatment, or could account for residual sleepiness in successfully CPAP-treated patients.

PATIENTS AND METHODS

In order to test this hypothesis, we compared objective sleepiness, assessed by the Multiple Sleep Latency Test (MSLT) and subjective sleep propensity, assessed by the Epworth Sleepiness Scale (ESS), in a clinical series of 57 patients consecutively diagnosed with OSAS (apnea/hypopnea index, 53.3+/-26.15), before and after 1 year of treatment with CPAP.

RESULTS

Twenty-two patients (38.5%) had significant PLMS (at least 5 PLMS/h of sleep; mean 52.9+/-53.9) in absence of apneas (with CPAP). The two groups (with and without PLMS) were similar in gender distribution, BMI, apnea/hypopnea index or CPAP level. Patients with PLMS were older than those without PLMS. Sleepiness measurements following OSAS diagnosis and after 1 year of CPAP treatment were similar in patients PLMS compared to those without significant PLMS. There was no correlation in the PLMS patient group between the PLM index, Epworth Sleepiness Scale score and mean latency in the MSLT.

CONCLUSION

In this study we did not find a link between PLMS and increased objective or self-evaluated sleepiness in OSAS patients, before or after treatment with CPAP.

Comparative effects of duloxetine and desipramine on sleep EEG in healthy subjects

RATIONALE

Antidepressants are known to modify human sleep patterns.

OBJECTIVES

Duloxetine is a new antidepressant with a mechanism of action involving reuptake inhibition of both serotonin (5-HT) and norepinephrine (NE). In this study, the effects of two dosing regimens of duloxetine on sleep electroencephalography (EEG) were investigated at steady-state plasma concentrations in young, healthy, male subjects.

METHODS

Placebo (n=12), desipramine (50 mg BID; n=12) and two regimens of duloxetine (80 mg QD, n=6; or 60 mg BID, n=6) were compared in a randomized, double-blind, three-period crossover study, each treatment being administered from day 1 to day 7. Sleep polygraphic recordings took place at baseline (day -1) and day 6 of each period. The Leeds sleep evaluation questionnaire (LSEQ) was also administered on the morning of day 7.

RESULTS

Both regimens of duloxetine produced a significant increase in the onset latency of REM sleep as well as a significant mean decrease in total REM sleep duration. Desipramine exhibited comparable effects. When compared to placebo, sleep continuity was significantly reduced with desipramine and duloxetine 60 mg BID whereas a significant improvement was observed with duloxetine 80 mg QD. On the LSEQ, duloxetine 80 mg QD produced a significant improvement in the "getting to sleep" subscale compared to placebo, whereas desipramine demonstrated a significant reduction (worsening) in the "quality of sleep" score versus placebo.

CONCLUSIONS

The two dose regimens of duloxetine (80 mg QD and 60 mg BID) produced a REM sleep pattern comparable to that of most antidepressant medications. Duloxetine 80 mg QD appeared to exhibit less impact upon sleep quality than duloxetine 60 mg BID in healthy subjects.

Sleep disturbances, psychiatric disorders, and psychotropic drugs

Brain neurotransmitter dysfunctions involved in the pathophysiological processes of psychiatric disorders are likely to be reflected by concomitant alterations in sleep continuity and architecture. Since the corrective effects of psychotropic drugs on dysfunctional neurotransmission systems can be evidenced through polysomnographic recordings, one may consider sleep as a kind of "window" on the neurobiology of psychiatric disorders. During the last 10 years, major breakthroughs in our understanding of sleep-wake mechanisms have provided some indications on how psychotropic drugs could influence the sleep-wake cycle. In this review, recent inroads into the understanding of sleep regulatory neural mechanisms are introduced and discussed in terms of the effects of psychotropic drugs. The relationship between the pathophysiological process of a disease, its consequence on sleep, and the corrective effect of a psychotropic drug are exemplified by two psychopathological states: substance withdrawal and major depression. One may conclude that polysomnographic recordings are a unique noninvasive tool to analyze brain functioning, and are particularly well suited to evaluating the objective effects of new psychotropic drugs.

What is the clinical significance of periodic limb movements during sleep?

To understand better the clinical impact of periodic limb movements during sleep (PLMS) we analysed data from 51 patients who, following an adaptation night, presented a PLMS index > 5 during two consecutive nocturnal polysomnographic recordings. In the morning following each recording patients completed a questionnaire including five visual analogic scales (VAS): (1) I did not sleep well/I slept very well. (2) I feel very sleepy/I do not feel sleepy at all. (3) I feel very tired/I feel very dynamic. (4) Physically, I do not feel fit/physically, I feel fit. (5) Psychologically, I do not feel fit/psychologically, I feel fit. We compared the responses to these questions with the PLMS index, first inter-individually, then intra-individually between nights.

RESULTS

The inter-individual analysis did not show correlations between the PLMS index and the questions (1) and (2). We found a significant correlation between the PLMS index and the questions (3) (r = -0.29; P < 0.05), (4) (r = -0.30; P < 0.05) and (5) (r = -0.39; P < 0.01). For the intra-individual analysis, we did not find correlations between the PLMS index and questions (1)-(3), but found a significant correlation with questions (4) (r = -0.28; P < 0.05) and (5) (r = -0.36; P < 0.01).

CONCLUSION

PLMS per se, or the sleep changes induced by them, seem to be associated with decreased physical and psychological fitness on awakening.

Sleep microstructure around sleep onset differentiates major depressive insomnia from primary insomnia

In the present study we investigate whether alterations of sleep propensity or of wake propensity are implicated in sleep initiation disturbances encountered in major depressive insomnia and in primary insomnia. For this purpose, the time course of electroencephalogram (EEG) power density during the period preceding sleep onset and during the first non-rapid eye movement (REM) period was examined in three age and gender matched groups of 10 women and 11 men (healthy controls, primary insomniacs and depressive insomniacs). In contrast to healthy controls and depressive insomniacs, patients with primary insomnia did not experience a gradual decrease of their alpha and beta1 power during the sleep onset period and had a lower delta activity in the 5 min preceding sleep onset. Compared with the two other groups, depressive patients exhibit less dynamic changes in slow wave activity during the first non-REM period. The present results suggest that hyperarousal (high 'Process W') may mainly be implicated in the sleep initiation difficulties of primary insomniacs whereas the homeostatic sleep regulation process seems to be partially maintained. In our major depressed patients, the sleep initiation disturbances appeared to relate to a lower sleep pressure (low 'Process S') rather than to hyperarousal. This study supports the idea that different mechanisms are implicated in sleep disturbances experienced by primary insomniacs and major depressive insomniacs.

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.

Periodic arousals or periodic limb movements during sleep?

Periodic limb movements during sleep (PLMS), frequently found in polysomnograms, are often accompanied by arousals. The relationship is not clear, however, because PLMS can occur before, after or simultaneous to the electromyographic (EMG) activation. We describe the case of a patient who presents PLMS during two of three consecutive recording nights, and periodic arousals without motor activation on the other night. We conclude that, at least in some patients with a periodic limb movement disorder, there exists an underlying arousal disorder that produces periodic activation and deactivation of the cerebral cortex.

[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.

Sleep and anxiety disorders

Sleep disturbances-particularly insomnia - are highly prevalent in anxiety disorders and complaints such as insomnia or nightmares have even been incorporated in some anxiety disorder definitions, such as generalized anxiety disorder and posttraumatic stress disorder. In the first part of this review, the relationship between sleep and anxiety is discussed in terms of adaptive response to stress. Recent studies suggested that the corticotropin-releasing hormone system and the locus ceruleus-autonomic nervous system may play major roles in the arousal response to stress. It has been suggested that these systems may be particularly vulnerable to prolonged or repeated stress, further leading to a dysfunctional arousal state and pathological anxiety states, Polysomnographic studies documented limited alteration of sleep in anxiety disorders. There is some indication for alteration in sleep maintenance in generalized anxiety disorder and for both sleep initiation and maintenance in panic disorder; no clear picture emerges for obsessive-compulsive disorder or posttraumatic stress disorder. Finally, an unequivocal sleep architecture profile that could specifically relate to a particular anxiety disorder could not be evidenced; in contrast, conflicting results are often found for the same disorder. Discrepancies between studies could have been related to illness severity, diagnostic comorbidity, and duration of illness. A brief treatment approach for each anxiety disorder is also suggested with a special focus on sleep.

Acute low single dose of apomorphine reduces periodic limb movements but has no significant effect on sleep arousals: a preliminary report

STUDY OBJECTIVES

To investigate the effects of apomorphine on the frequency of periodic limb movements during sleep (PLMS) and on sleep architecture.

DESIGN

Nine patients presenting PLMS (including eight patients with restless legs syndrome) underwent three consecutive night sleep recordings. They received a single dose of 0.5 mg subcutaneous apomorphine at bedtime the third night.

RESULTS

When computing PLMS during four 2-h periods of sleep, a significant period by apomorphine-effect was demonstrated, with a marked reduction of PLMS during the first 4 h post-injection (P < 0.01). No significant differences were found in sleep macroarchitecture between the three recorded nights, excepted a slight reduction in sleep latency during the third night (P < 0.05). Despite the decreased number of PLMS after apomorphine injection, there were significant changes neither in the total number of arousals nor in the index of arousals per hour of sleep.

CONCLUSION

Our results add further support to the dopaminergic hypothesis in the generation of PLMS. The persistence of arousals suggests that they are not simply the consequence of PLMS but a primary phenomenon, not related with the dopaminergic system.

Double-blind, placebo-controlled study of the efficacy of trazodone in alcohol post-withdrawal syndrome: polysomnographic and clinical evaluations

Alcohol detoxification is accompanied by sustained difficulties in sleep initiation and maintenance. These difficulties are thought to be an important cause of relapse to alcohol use. However, the treatment of sleep problems with hypnotic drug is made difficult by cross-tolerance between benzodiazepines and alcohol. In this report, we evaluated the capacity of trazodone (TRZ), a second-generation antidepressant with anxiolytic and sedative properties, to increase the sleep efficiency in alcohol-dependent patients after detoxification. Sixteen patients completed the TRZ (n = 8) or the placebo (PL; n = 8) treatment arms. Polysomnographies were performed at baseline, after the 1st drug dose, and after 4 weeks of treatment. The main outcome was sleep efficiency. Secondary outcomes included changes in other sleep parameters, Hamilton Depression Rating and Clinical Global Impression scales. Sleep efficiency was increased in the TRZ group when it was computed after sleep onset, both immediately after 1st administration of the drug and after 4 weeks of treatment. No benefit was observed in the PL group. Sleep improvement under TRZ also included the number of awakenings, intermittent wake sleep time, and non-rapid eye movement sleep. Hamilton and Clinical Global scales were better for the TRZ group. TRZ is thus a potential option in the treatment of alcohol post-withdrawal insomnia.

Sleep-wake mechanisms and drug discovery: sleep EEG as a tool for the development of CNS-acting drugs

Sleep laboratory investigations constitute a unique noninvasive tool to analyze brain functioning, Polysomnographic recordings, even in the very early phase of development in humans, are mandatory in a developmental plan of a new sleep-acting compound. Sleep is also an interesting tool for the development of other drugs acting on the central nervous system (CNS), Indeed, changes in sleep electroencephalographic (EEG) characteristics are a very sensitive indication of the objective central effects of psychoactive drugs, and these changes are specific to the way the drug acts on the brain neurotransmitter systems. Moreover, new compounds can be compared with reference drugs in terms of the sleep EEG profile they induce. For instance, cognitive enhancers involving cholinergic mechanism have been consistently demonstrated to increase rapid eye movement (REM) sleep pressure, and studying drug-induced slow wave sleep (SWS) alteration is a particularly useful tool for the development of CNS compounds acting at the 5-HT(2A/C) receptor, such as most atypical antipsychotics and some antidepressant drugs. The sleep EEG profile of antidepressants, and particularly their effects on REM sleep, are specific to their ability to enhance noradrenergic or serotonergic transmission, it is suggested that the effects of noradrenergic versus serotonergic reuptake inhibition could be disentangled using specific monoamine depletion tests and by studying drug effects on sleep microsiructure.

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.

Psychiatric disorders and social characteristics among second-generation Moroccan migrants in Belgium: an age-and gender-controlled study conducted in a psychiatric emergency department

PURPOSE

Clinically, one of the most consistent clinical findings among migrant patients is an increase in the rate of psychosis. The aim of the present study was to confirm this finding in Belgium by comparing second-generation Moroccan migrant patients with Belgian patients, matched for the variables of age and gender.

SUBJECTS AND METHOD

We conducted a cross-sectional survey on 272 patients admitted in a psychiatric emergency unit during the year 1998. We used univariate and multivariate analyses to compare the two subgroups.

RESULTS

Multivariate analyses showed that migrant patients lived more often with their parental family and that they presented a higher rate of admission for psychotic disorders and a lower rate of employment.

DISCUSSION

Our findings add to the growing body of results showing increased incidence of psychosis among immigrants to European countries, but several factors have to be taken into account, particularly with regard to selection biases and differences in help-seeking behaviour and in family perception of the mental illness.

CONCLUSION

Our results are compatible with the hypothesis that unemployment is a contributing factor in the risk for psychosis among migrant groups. Further studies would be needed to better explain some of our results, particularly the role played by the families of migrant patients.

Sleep-wake mechanisms and drug discovery: sleep EEG as a tool for the development of CNS-acting drugs

Sleep laboratory investigations constitute a unique noninvasive tool to analyze brain functioning, Polysomnographic recordings, even in the very early phase of development in humans, are mandatory in a developmental plan of a new sleep-acting compound. Sleep is also an interesting tool for the development of other drugs acting on the central nervous system (CNS), Indeed, changes in sleep electroencephalographic (EEG) characteristics are a very sensitive indication of the objective central effects of psychoactive drugs, and these changes are specific to the way the drug acts on the brain neurotransmitter systems. Moreover, new compounds can be compared with reference drugs in terms of the sleep EEG profile they induce. For instance, cognitive enhancers involving cholinergic mechanism have been consistently demonstrated to increase rapid eye movement (REM) sleep pressure, and studying drug-induced slow wave sleep (SWS) alteration is a particularly useful tool for the development of CNS compounds acting at the 5-HT(2A/C) receptor, such as most atypical antipsychotics and some antidepressant drugs. The sleep EEG profile of antidepressants, and particularly their effects on REM sleep, are specific to their ability to enhance noradrenergic or serotonergic transmission, it is suggested that the effects of noradrenergic versus serotonergic reuptake inhibition could be disentangled using specific monoamine depletion tests and by studying drug effects on sleep microsiructure.

A dimensional impulsive-aggressive phenotype is associated with the A218C polymorphism of the tryptophan hydroxylase gene: a pilot study in well-characterized impulsive inpatients

Tryptophan hydroxylase (TPH) is the rate-limiting enzyme in the biosynthesis of serotonin, and association and linkage studies of its variants in suicidal and impulsive-aggressive behavior have brought conflicting results. This pilot study was designed to investigate whether TPH A218C genotypes could be associated with impulsive behavioral tendencies (IBTs) in consecutively admitted nonpsychotic nonorganic inpatients. Patients (20 females and 34 males; age, 38.8 +/- 11.8) did not differ from healthy nonimpulsive controls (16 females and 11 males; age, 35.2 +/- 10.2) regarding TPH genotypes, but in the patients, the number of IBT was related to the presence of the 218C allele. It was concluded that impulsive-aggressive behavior may be associated with the TPH genotype in well-characterized impulsive patients and that the present results stress the importance of considering impulsiveness-aggressiveness in studies investigating the relationship between suicidal behavior and TPH genotypes.

Correlations using the NREM-REM sleep cycle frequency support distinct regulation mechanisms for REM and NREM sleep

Polysomnograms of most homeothermic species distinguish two states, rapid eye movement (REM) and non-REM (NREM) sleep. These alternate several times during the night for reasons and following rules that remain poorly understood. It is unknown whether each state has its own function and regulation or whether they represent two facets of the same process. The present study compared the mean REM/NREM sleep ratio and the mean number of NREM-REM sleep cycles across 3 consecutive nights. The rationale was that, if REM and NREM sleep are tightly associated, their ratio should be comparable whatever the cycle frequency in the night. Twenty-six healthy subjects of both sexes were recorded at their home for 4 consecutive nights. The correlation between the REM/NREM sleep ratio and the number of cycles was highly significant. Of the two sleep components, REM sleep was associated to the number of cycles, whereas NREM sleep was not. This suggests that the relationship between REM sleep and NREM sleep is rather weak within cycles, does not support the concept of NREM-REM sleep cycles as miniature units of the sleep process, and favors the concept of distinct mechanisms of regulation for the two components.

Serotonergic function and suicidal behavior in schizophrenia

Recent studies suggest that altered serotonergic (5-HT) function, as assessed by lower prolactin (PRL) response to fenfluramine (FEN), a specific 5-HT releaser and uptake inhibitor, is associated with suicidal behavior in either depressed and personality disordered patients. The purpose of this study was to investigate, in schizophrenic patients, the relationship between suicidal behavior and PRL response to D-fenfluramine (D-FEN). A D-FEN test was performed in 18 healthy controls and 33 drug-free DSM-IV schizophrenic patients (12 with a history of suicide attempts, 21 without it). Schizophrenic patients with a history of suicide attempts showed a lower PRL response to D-FEN (Delta PRL) compared to schizophrenic patients without such history (P<0.04) and also compared to healthy controls (P<0.0003). Delta PRL did not differentiate schizophrenic patients without suicide attempts and controls. These findings could not be explained by PRL basal hormonal levels, age, sex, menstrual status, demographic or clinical characteristics. These results suggest that PRL response to D-FEN is a marker of suicidal tendencies also in schizophrenia, supporting the hypothesis that a dysfunction in serotonergic function is associated with suicidal behavior regardless of the psychiatric diagnosis.