The electroencephalographic sleep pattern in schizophrenic patients treated with clozapine or classical antipsychotic drugs

Sleep quality and cognitive impairments in remitted patients with schizophrenia in Nigeria

BACKGROUND

Despite the ubiquity of sleep disturbance in schizophrenia, it has generally been overlooked as a potential contributor to cognitive impairments. The main aim of this study was to find out if impaired sleep quality contributes to cognitive impairments in patients with a diagnosis of schizophrenia who are in remission.

METHODS

The study was conducted at the University College Hospital, Ibadan and State Hospital, Ibadan, Nigeria. The Pittsburgh Sleep Quality Index (PSQI) and Screen for Cognitive Impairment in Psychiatry (SCIP) were applied in this cross-sectional study, to all consecutive and consenting remitted outpatients with schizophrenia (N=130). Other instruments such as Hamilton Depression Rating Scale (HDRS), the Positive and Negative Syndrome Scale (PANSS), sociodemographic and clinical measures were also applied.

RESULTS

There were 130 participants made up of 69 females (53.1%) and 61males(46.9%). The mean age of the participants was 38.5±9.1 years. The prevalence of poor sleep quality in remitted patients with schizophrenia was 56.9%. Sleep quality was significantly negatively correlated with Verbal Learning Test-Immediate (VLT-I) (r(128)=-.18, P=.044) and Verbal Learning Test-Delayed (VLT-D) (r(128)=-.18, P=.037). The variables that independently predicted cognitive functioning were the VLT-I, odds ratio (OR) 0.66; 95% confidence interval ((CI) 0.49-0.88) and education (OR) 0.61;(CI) 0.40- 0.92).

CONCLUSION

Poor subjective sleep quality measured by the PSQI is linked to cognitive impairment in remitted patients with schizophrenia. We suggest that sleep quality in remitted patients with a diagnosis of schizophrenia should receive better attention by physicians.

International Union of Basic and Clinical Pharmacology. CX. Classification of Receptors for 5-hydroxytryptamine; Pharmacology and Function

5-HT receptors expressed throughout the human body are targets for established therapeutics and various drugs in development. Their diversity of structure and function reflects the important role 5-HT receptors play in physiologic and pathophysiological processes. The present review offers a framework for the official receptor nomenclature and a detailed understanding of each of the 14 5-HT receptor subtypes, their roles in the systems of the body, and, where appropriate, the (potential) utility of therapeutics targeting these receptors. SIGNIFICANCE STATEMENT: This review provides a comprehensive account of the classification and function of 5-hydroxytryptamine receptors, including how they are targeted for therapeutic benefit.

Risperidone Provides Better Improvement of Sleep Disturbances Than Haloperidol Therapy in Schizophrenia Patients With Cannabis-Positive Urinalysis

A high percentage of persons with Schizophrenia also uses Cannabis and this may potentially alter the therapeutic benefits of the antipsychotic medications prescribed. The aim of this study was to assess the impact of Cannabis usage on antipsychotic therapy of sleep disturbances in schizophrenia subjects. Male subjects, ≥18 years, admitted to the University Hospital of the West Indies psychiatric ward between October 2015 and October 2016, and diagnosed with schizophrenia were recruited for the study. Following written informed consent to the study, subjects were prescribed either risperidone monotherapy or haloperidol monotherapy orally for 14 days and classified as Cannabis users (CU) or non-users (non-CU), with presence/absence of Cannabis metabolite in urine samples. After 1 week of admission, subjects wore the Actiwatch-2 device, to record sleep data for 7 consecutive nights. Inferential statistical analysis involved non-parametric tests, expressed as median and inter-quartile ranges (IQR), with p<0.05 considered statistically significant. Fifty subjects were assessed, with a median (IQR) age of 28 (14) years. Majority (30; 60%) were CU, displaying longer sleep latency (SL) than non-CU when receiving haloperidol; but equivalent SL when receiving risperidone. In comparison to non-CU, the CU also displayed longer time in bed, but shorter durations asleep, awoke more frequently during the nights and for longer durations, whether receiving haloperidol or risperidone. This resulted in lower sleep efficiency for the CU (<85%) compared to the non-CU (≥85%). Over the study period, sleep efficiency was significantly improved for non-CU receiving either risperidone (p = 0.032) or haloperidol (p = 0.010); but was only significantly improved with risperidone for the CU (p = 0.045). It is apparent that the presence of Cannabis may be impacting the therapeutic benefits of antipsychotic drugs on sleep. In schizophrenia subjects with concomitant Cannabis use, risperidone is more beneficial than haloperidol in improving sleep efficiency.

Adverse Effects of Psychotropic Medications on Sleep

Psychotropic medications such as antidepressants, antipsychotics, stimulants, and benzodiazepines are widely prescribed. Most of these medications are thought to exert their effects through modulation of various monoamines as well as interactions with receptors such as histamine and muscarinic cholinergic receptors. Through these interactions, psychotropics can also have a significant impact on sleep physiology, resulting in both beneficial and adverse effects on sleep.

The effect of second-generation antipsychotic drugs on sleep parameters in patients with unipolar or bipolar disorder

Sleep disturbances predominantly take the form of insomnia in patients with unipolar disorder, while patients with bipolar disorder show a decreased need for sleep. Sleep impairment in these patients is a risk factor for the development of a major depressive episode and suicidal behavior. Administration of second-generation antipsychotics (SGAs) olanzapine, quetiapine, and ziprasidone as augmentation therapy or monotherapy to unipolar and bipolar disorder patients, respectively, has been shown to improve sleep continuity and sleep architecture. Thus, their use by these patients could ameliorate their sleep disorder.

Sleep EEG and spindle characteristics after combination treatment with clozapine in drug-resistant schizophrenia: a pilot study

PURPOSE

Clozapine is an atypical neuroleptic agent, effective in treating drug-resistant schizophrenia. The aim of this work was to investigate overall sleep architecture and sleep spindle morphology characteristics, before and after combination treatment with clozapine, in patients with drug-resistant schizophrenia who underwent polysomnography.

METHODS

Standard polysomnographic techniques were used. To quantify the sleep spindle morphology, a modeling technique was used that quantifies time-varying patterns in both the spindle envelope and the intraspindle frequency.

RESULTS

After combination treatment with clozapine, the patients showed clinical improvement. In addition, their overall sleep architecture and, more importantly, parameters that quantify the time-varying sleep spindle morphology were affected. Specifically, the results showed increased stage 2 sleep, reduced slow-wave sleep, increased rapid eye movement sleep, increased total sleep time, decreased wake time after sleep onset, as well as effects on spindle amplitude and intraspindle frequency parameters. However, the above changes in overall sleep architecture were statistically nonsignificant trends.

CONCLUSIONS

The findings concerning statistically significant effects on spindle amplitude and intraspindle frequency parameters may imply changes in cortical sleep EEG generation mechanisms, as well as changes in thalamic pacing mechanisms or in thalamo-cortical network dynamics involved in sleep EEG generation, as a result of combination treatment with clozapine.

SIGNIFICANCE

Sleep spindle parameters may serve as metrics for the eventual development of effective EEG biomarkers to investigate treatment effects and pathophysiological mechanisms in schizophrenia.

Olanzapine and clozapine differently affect sleep in patients with schizophrenia: results from a double-blind, polysomnographic study and review of the literature

Schizophrenia is associated with impaired sleep continuity. The second generation antipsychotics clozapine and olanzapine have been reported to improve sleep continuity but also to rarely induce restless legs syndrome (RLS). The aims of this randomized double-blind study were to compare the effects of clozapine and olanzapine on sleep and the occurrence of RLS. Therefore, polysomnographies were recorded and RLS symptoms were assessed in 30 patients with schizophrenia before and after 2, 4 and 6 weeks of treatment with either clozapine or olanzapine. Treatment with both antipsychotics increased total sleep time, sleep period time and sleep efficiency and decreased sleep onset latency. These changes were similar in both groups, occurred during the first 2 treatment weeks and were sustained. For example, sleep efficiency increased from 83% (olanzapine) and 82% (clozapine) at baseline to 95% at week 2 and 97% at week 6 in both treatment groups. Sleep architecture was differently affected: clozapine caused a significantly stronger increase of stage 2 sleep (44%) than olanzapine (11%) but olanzapine a significantly stronger increase of REM-sleep. Olanzapine caused an 80% increase of slow wave sleep whereas clozapine caused a 6% decrease. No patient reported any of 4 RLS defining symptoms at baseline. During treatment, 1 patient of each group reported at one visit all 4 symptoms, i.e. met the diagnosis of an RLS. In conclusion, sleep continuity similarly improved and sleep architecture changed more physiologically with olanzapine. Neither of the antipsychotics induced RLS symptoms that were clinically relevant.

Do sleep abnormalities and misaligned sleep/circadian rhythm patterns represent early clinical characteristics for developing psychosis in high risk populations?

Sleep architecture changes, such as slow-wave sleep (SWS) percentage variations and reductions in latency and density of rapid eye movement (REM), are found in most patients with schizophrenia and are considered to be an important part of the pathophysiology of the disorder. In addition to these sleep parameters changes, disruptions in sleep homeostasis and the sleep/circadian rhythm also occur in these patients. Sleep/circadian rhythm abnormalities negatively affect neocortical plasticity and cognition and often precede the diagnosis of the illness. Thus, it has been suggested that the sleep/circadian rhythm might be involved in the pathophysiology of psychosis. Recent advances in the identification of individuals at a high risk for developing schizophrenia allow us to investigate several neurobiological processes involved in the development of psychosis. In this article, we review the current evidence of the effects of sleep parameter abnormalities, disruptions in sleep homeostasis and misalignments of sleep circadian rhythm on the early stages of schizophrenia. In addition, we discuss the preliminary evidence of sleep and circadian rhythm abnormalities during the prodromal stages of psychosis and propose that these abnormalities can be explored as potential predictors, as an adjunct to clinical diagnosis, of developing a psychotic disorder in at risk populations.

Sleep habits in middle-aged, non-hospitalized men and women with schizophrenia: a comparison with healthy controls

Patients with schizophrenia may have sleep disorders even when clinically stable under antipsychotic treatments. To better understand this issue, we measured sleep characteristics between 1999 and 2003 in 150 outpatients diagnosed with Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) schizophrenia or schizoaffective disorder and 80 healthy controls using a sleep habits questionnaire. Comparisons between both groups were performed and multiple comparisons were Bonferroni corrected. Compared to healthy controls, patients with schizophrenia reported significantly increased sleep latency, time in bed, total sleep time and frequency of naps during weekdays and weekends along with normal sleep efficiency, sleep satisfaction, and feeling of restfulness in the morning. In conclusion, sleep-onset insomnia is a major, enduring disorder in middle-aged, non-hospitalized patients with schizophrenia that are otherwise clinically stable under antipsychotic and adjuvant medications. Noteworthy, these patients do not complain of sleep-maintenance insomnia but report increased sleep propensity and normal sleep satisfaction. These results may reflect circadian disturbances in schizophrenia, but objective laboratory investigations are needed to confirm subjective sleep reports.

GABA(B) receptors, schizophrenia and sleep dysfunction: a review of the relationship and its potential clinical and therapeutic implications

Evidence for an intrinsic relationship between sleep, cognition and the symptomatic manifestations of schizophrenia is accumulating. This review presents evidence for the possible utility of GABA(B) receptor agonists for the treatment of subjective and objective sleep abnormalities related to schizophrenia. At the phenotypic level, sleep disturbance occurs in 16-30% of patients with schizophrenia and is related to reduced quality of life and poor coping skills. On the neurophysiological level, studies suggest that sleep deficits reflect a core component of schizophrenia. Specifically, slow-wave sleep deficits, which are inversely correlated with cognition scores, are seen. Moreover, sleep plays an increasingly well documented role in memory consolidation in schizophrenia. Correlations of slow-wave sleep deficits with impaired reaction time and declarative memory have also been reported. Thus, both behavioural insomnia and sleep architecture are critical therapeutic targets in patients with schizophrenia. However, long-term treatment with antipsychotics often results in residual sleep dysfunction and does not improve slow-wave sleep, and adjunctive GABA(A) receptor modulators, such as benzodiazepines and zolpidem, can impair sleep architecture and cognition in schizophrenia. GABA(B) receptor agonists have therapeutic potential in schizophrenia. These agents have minimal effect on rapid eye movement sleep while increasing slow-wave sleep. Preclinical associations with increased expression of genes related to slow-wave sleep production and circadian rhythm function have also been reported. GABA(B) receptor deficits result in a sustained hyperdopaminergic state and can be reversed by a GABA(B) receptor agonist. Genetic, postmortem and electrophysiological studies also associate GABA(B) receptors with schizophrenia. While studies thus far have not shown significant effects, prior focus on the use of GABA(B) receptor agonists has been on the positive symptoms of schizophrenia, with minimal investigation of GABA(B) receptor agonists such as baclofen or gamma-hydroxybutyric acid and their effects on sleep architecture, cognition and negative symptoms in patients with schizophrenia. Further study is needed.

Correlation of attention deficit, rapid eye movement latency and slow wave sleep in schizophrenia patients

AIM

Schizophrenia patients present both reduced slow wave sleep (SWS) and shortened rapid eye movement latency (REML) in polysomnographic (PSG) profiles, which have been linked to dopaminergic and muscarinic impairment, respectively. Two main selective attentional systems involve different anatomical structures. The first system is the parietal cortical areas and thalamic areas, which are linked to cholinergic neurotransmission. This is responsible for automatic attention response. The second system is the frontal regions, which are linked to dopaminergic neurotransmission. This is responsible for voluntary control of attentional resources. It was hypothesized that low attentional performance in schizophrenia patients is associated with shortened REML and reduced SWS.

METHODS

The PSG profile was correlated with the continuous performance test (CPT) in 15 schizophrenia inpatients under treatment with risperidone. Schizophrenia was diagnosed according to DSM-IV criteria, and clinical symptoms were evaluated on the Brief Psychiatric Rating Scale.

RESULTS

REML was negatively correlated with errors of omission (P < 0.05), reaction time (RT; P < 0.05) and positively correlated with hit rate (HR; P < 0.05). No association was found between SWS and CPT performance.

CONCLUSIONS

The significant indicators of CPT represent different attention processes. Errors of omission, which are linked to the problems with automatic attention processing, RT, which represent the speed of automatic processing, and HR, are involved in the integration of autonomic and voluntary attention control. The present results suggest that REML is associated with thalamus-related automatic attention response. Due to study limitations, however, confirmation of these findings in a large-scale controlled study of drug-naïve patients is needed.

Sleep disturbances in patients with schizophrenia : impact and effect of antipsychotics

Difficulties initiating or maintaining sleep are frequently encountered in patients with schizophrenia. Disturbed sleep can be found in 30-80% of schizophrenic patients, depending on the degree of psychotic symptomatology. Measured by polysomnography, reduced sleep efficiency and total sleep time, as well as increased sleep latency, are found in most patients with schizophrenia and appear to be an important part of the pathophysiology of this disorder. Some studies also reported alterations of stage 2 sleep, slow-wave sleep (SWS) and rapid eye movement (REM) sleep variables, i.e. reduced REM latency and REM density. A number of sleep parameters, such as the amount of SWS and the REM latency, are significantly correlated to clinical variables, including severity of illness, positive symptoms, negative symptoms, outcome, neurocognitive impairment and brain structure.Concerning specific sleep disorders, there is some evidence that schizophrenic patients carry a higher risk of experiencing a sleep-related breathing disorder, especially those demonstrating the known risk factors, including being overweight but also long-term use of antipsychotics. However, it is still unclear whether periodic leg movements in sleep or restless legs syndrome (RLS) are found with a higher or lower prevalence in schizophrenic patients than in healthy controls.There are no consistent effects of first-generation antipsychotics on measures of sleep continuity and sleep structure, including the percentage of sleep stages or sleep and REM latency in healthy controls. In contrast to first-generation antipsychotics, the studied atypical antipsychotics (clozapine, olanzapine, quetiapine, risperidone, ziprasidone and paliperidone) demonstrate a relatively consistent effect on measures of sleep continuity, with an increase in either total sleep time (TST) or sleep efficiency, and individually varying effects on other sleep parameters, such as an increase in REM latency observed for olanzapine, quetiapine and ziprasidone, and an increase in SWS documented for olanzapine and ziprasidone in healthy subjects.The treatment of schizophrenic patients with first-generation antipsychotics is consistently associated with an increase in TST and sleep efficiency, and mostly an increase in REM latency, whereas the influence on specific sleep stages is more variable. On the other hand, withdrawal of such treatment is followed by a change in sleep structure mainly in the opposite direction, indicating a deterioration of sleep quality. On the background of the rather inconsistent effects of first-generation antipsychotics observed in healthy subjects, it appears possible that the high-potency drugs exert their effects on sleep in schizophrenic patients, for the most part, in an indirect way by suppressing stressful psychotic symptomatology. In contrast, the available data concerning second-generation antipsychotics (clozapine, olanzapine, risperidone and paliperidone) demonstrate a relatively consistent effect on measures of sleep continuity in patients and healthy subjects, with an increase in TST and sleep efficiency or a decrease in wakefulness. Additionally, clozapine and olanzapine demonstrate comparable influences on other sleep variables, such as SWS or REM density, in controls and schizophrenic patients. Possibly, the effects of second-generation antipsychotics observed on sleep in healthy subjects and schizophrenic patients might involve the action of these drugs on symptomatology, such as depression, cognitive impairment, and negative and positive symptoms.Specific sleep disorders, such as RLS, sleep-related breathing disorders, night-eating syndrome, somnambulism and rhythm disorders have been described as possible adverse effects of antipsychotics and should be considered in the differential diagnosis of disturbed or unrestful sleep in this population.

Sleep in schizophrenia: impairments, correlates, and treatment

In untreated schizophrenia, psychotic decompensation is associated with profound insomnia, one of the prodromal symptoms associated with psychotic relapse. First- and second-generation antipsychotic medication can ameliorate this insomnia, but side effects may include sedation or residual insomnia. Patients who are clinically stable and medicated may continue to experience disturbed sleep, including long sleep-onset latencies, poor sleep efficiency, slow wave sleep deficits, and short rapid eye movement latencies. Schizophrenia also can be associated with comorbid sleep disorders, which may be enhanced or induced by antipsychotic medication. Sleep disorders in schizophrenia should be treated vigorously because normalized sleep and its restorative processes may be essential for a positive clinical outcome.

Quality of sleep in patients with schizophrenia is associated with quality of life and coping

BACKGROUND

While sleep disturbance is widespread in schizophrenia it is less clear whether sleep disturbance is uniquely related to impaired coping and perceived quality of life.

METHODS

We simultaneously assessed sleep quality, symptoms, and coping in 29 persons with schizophrenia or schizoaffective disorder in a post acute phase of illness. Assessment instruments included the Pittsburgh Sleep Quality Index; the Positive and Negative Symptom Scale; the Heinrichs Quality of Life Scale; and the Ways of Coping Scale. Multiple regressions were performed predicting quality of life and coping from sleep quality controlling for age and symptom severity. On a subset of seven subjects non-dominant wrist actigraphy was used as an objective check of their self-reported poor sleep.

RESULTS

Analyses revealed that poor sleep quality predicted low quality of life (r = -0.493; p = .022) and reduced preference for employing positive reappraisal when facing a stressor (r = -0.0594; p = 0.0012). Actigraphy confirmed poor sleep quality in a subset of subjects. They had shorter sleep duration (p < .0005), shorter average sleep episodes (p < .005) and more episodes of long awakening (p < 0.05) than community norms.

CONCLUSION

The results are consistent with the hypotheses that poor sleep may play a unique role in sustaining poor quality of life and impaired coping in patients with schizophrenia. These associations may hold for community controls as well.

Sleep quality in schizophrenia and the effects of atypical antipsychotic medication

BACKGROUND

Sleep disorders are widespread among patients with schizophrenia and contribute to adverse clinical outcomes. Antipsychotic drugs exert varying effects on sleep, and the effects of atypical agents may differ from those of conventional neuroleptics.

OBJECTIVE

To review the literature on the effects of atypical medication on subjective and objective sleep quality in patients with schizophrenia.

METHODS

A non-systematic literature review of Medline was performed in August 2003 searching the period from January 1985 to August 2003 for studies of the effects of atypical antipsychotics on sleep.

RESULTS

We found published studies of clozapine, olanzapine, and risperidone, but none on quetiapine or ziprasidone. Studies with clozapine showed that it increased total sleep time, sleep efficiency, stage-2 non-rapid eye movement sleep and rapid eye movement (REM) sleep density, and decreased stage-4 sleep, slow wave sleep (SWS) and stage-1 sleep. Single-dose studies with olanzapine have shown that it increases SWS, sleep continuity, total sleeping time, subjective sleep quality, and delta sleep. Long-term studies with risperidone have shown improvements in total sleep, sleep efficiency, sleep continuity, SWS, and stage-2 sleep, and reductions in sleep latency, number of awakenings, and proportion of time awake. These benefits were paralleled by improvements in subjective sleep assessment and psychopathology, and psychosocial functioning.

CONCLUSIONS

The evidence presented in this review suggests that atypical antipsychotics exert favorable effects on sleep profile compared with conventional agents, including improvement of subjective sleep quality and modification of specific sleep stages known to be associated with better clinical outcome.

Effects of clozapine on sleep in bipolar and schizoaffective disorders

OBJECTIVE

Sleep disturbances are strongly associated with mood disorders, although the majority of data have been obtained in patients with major depressive disorder. Studies reporting results in bipolar disorder are few, and results have not been consistent. Clozapine is a prototype of atypical antipsychotics, which is effective in improving symptoms of manic episodes in patients with bipolar disorder, or schizoaffective disorder, bipolar type and has been shown to influence sleep in other psychiatric disorders. The present study evaluated the sleep effects of clozapine in bipolar and schizoaffective disorders.

METHODS

Participants were 11 women and 4 men (range:28-53 years of age, mean 40.9+/-8.6 years), all with a history of mania by DSM-IV criteria for either bipolar I disorder or schizoaffective disorder, bipolar type. They participated in a sleep study at baseline and again after 6 months initiation of clozapine add-on therapy.

RESULTS

Sleep latency was longer on clozapine and the number of awakenings were increased, whereas time in bed (TIB) and total sleep period (TSP) were increased (range: F=6.2-17.9; df=l,12; p<0.05). Although none of the individual sleep stage showed significant treatment changes, both Stage 2 and slow-wave sleep were increased and Stage 2 decreased on clozapine. Subjective sleep measures improved on clozapine with a small but significant improvement in how rested patients felt upon awakening (t=-2.1; df=26; p<0.05).

CONCLUSION

Clozapine prolonged sleep latency, improved restedness, and increased total sleep time. Although lack of a control group limits interpretation of these results, they are in general agreement with studies in other psychiatric populations, and support the view that clozapine is primarily a NREM sleep enhancer. The improvement in restedness may be of positive clinical consequence.

Genetic dissection of drug effects in clinical practice: CLOCK gene and clozapine-induced diurnal sleepiness

Psychotic patients treated with clozapine often experience persistent daytime sleepiness. This is a frequent side effect of clozapine that may reduce patient compliance. We hypothesized that clozapine might interfere with the circadian rhythms regulated by the biological clock. In 171 patients with major psychosis, we investigated the association between hypersomnolence during clozapine therapy and a CLOCK gene polymorphism (3111 T/C substitution). Forty-six patients showed persistent daytime sleepiness and were classified as "sleepy". "Sleepy" patients were significantly more likely to have a mutated allele compared to both "non sleepy" patients and healthy subjects (chi2 = 20.36, d.f. = 1, P = 0.000007, and chi2 = 13.91, d.f. = 1, P = 0.0002, respectively). We conclude that an interaction between clozapine and the CLOCK gene polymorphism 3111 T/C substitution could explain persistent daytime sleepiness in a significant proportion of patients treated with clozapine.

Sleep in schizophrenia patients and the effects of antipsychotic drugs

Insomnia is a common feature in schizophrenia. However, it seldom is the predominant complaint. Nevertheless, severe insomnia is often seen during exacerbations of schizophrenia, and may actually precede the appearance of other symptoms of relapse. The sleep disturbances of either never-medicated or previously treated schizophrenia patients are characterized by a sleep-onset and maintenance insomnia. In addition, stage 4 sleep, slow wave sleep (stages 3 and 4), non-REM (NREM) sleep in minutes and REM latency are decreased. The atypical antipsychotics olanzapine, risperidone, and clozapine significantly increase total sleep time and stage 2 sleep. Moreover, olanzapine and risperidone enhance slow wave sleep. On the other hand, the typical antipsychotics haloperidol, thiothixene, and flupentixol significantly reduce stage 2 sleep latency and increase sleep efficiency. Future research should address: (1) the sleep patterns in subtypes of schizophrenia patients; (2) the role of neurotransmitters other than dopamine in the disruption of sleep in schizophrenia; (3) the functional alterations in CNS areas related to the pathophysiology of schizophrenia during NREM sleep and REM sleep (brain imaging studies); (4) the short-term, intermediate-term, and long-term effects of atypical antisychotics on sleep variables.

Clozapine alters sleep-wake behavior in rats

Clozapine is an atypical antipsychotic agent showing therapeutic efficacy superior to that of classical neuroleptics. Clozapine has strong sedative effects, but detailed studies on the drug influencing sleep in rodents are lacking. We studied the effects of clozapine on sleep and body temperature in rats. Clozapine (0, 2.5, and 7.5 mg/kg) was given i.p. to male Wistar rats at the beginning of the rest period. After administration of 7.5 mg/kg clozapine, animals were significantly more awake during the first 2 h postinjection. In parallel, the slow-wave activity (SWA) was suppressed. In the following 2 h non-REM sleep was markedly increased, whereas the SWA returned to baseline. At both doses clozapine decreased overall wakefulness and increased non-REM sleep on the first treatment day, which was associated with prolonged non-REM sleep episodes. These effects were transiently present even after subchronic treatment (7 days). After acute treatment, 7.5 mg/kg clozapine significantly reduced REM sleep and pre-REM sleep due to an increase in REM sleep latency and a reduction in the number of REM sleep episodes. Furthermore, clozapine produced a transient decrease in brain temperature that was followed by a moderate, but long-lasting elevation. To conclude, clozapine affected sleep-wake behavior in a way comparable to its effects in humans, suggesting that the rat is a suitable model for further studies on the underlying mechanisms.

Case study of circadian rhythm sleep disorder following haloperidol treatment: reversal by risperidone and melatonin

A patient with Gilles de la Tourette syndrome treated with haloperidol, ingested once daily after awakening from sleep, exhibited an irregular sleep-wake pattern with a free-running component of approximately 48 h. Transfer to risperidone, ingested once daily after awakening from sleep, was beneficial resulting in a sleep-wake cycle more synchronized at the appropriate phase to the external zeitgebers, and fewer nocturnal disturbances. The circadian sleep-wake schedule was fully synchronized when the patient had been subsequently treated with melatonin at 21:00h, before intended nocturnal sleep, in addition to risperidone in the morning. Restoration of the sleep-wake circadian pattern was accompanied by the patient's subjective report of significant improvement in his quality of life, social interactions, and occupational status. This observation suggests that circadian rhythm sleep disorders can be related to the typical neuroleptic haloperidol and restored by the atypical neuroleptic risperidone. Similar findings reported in patients suffering from other disorders support the hypothesis that the described disruption of the sleep-wake schedule is medication rather than illness-related. Therefore, it is very important to realize that circadian rhythm sleep disorders may be a side effect of neuroleptics.

Effects of clozapine on sleep measures and sleep-associated changes in growth hormone and cortisol in patients with schizophrenia

There have been limited reports on the effect of the atypical anti-psychotic agent clozapine on sleep measures and hormone secretion. The goal of this study was to determine the type, rate, and extent of changes in sleep measures and nighttime secretion of growth hormone (GH) and cortisol during clozapine treatment. Five schizophrenic patients (age: 32.4+/-7.4) and five age- and sex-matched normal subjects (age: 33.0+/-5.1) underwent nocturnal polysomnography (NPSG) before clozapine therapy (S1), and during early and late clozapine therapy (S2 and S3). Serum GH and cortisol levels were monitored during each NPSG. NPSG findings showed that the mean total sleep time, sleep efficiency, and duration of awakening were increased at S2, and maintained until S3. The mean amounts of stage 2 sleep at S2 and S3 increased significantly compared with that of S1. In unmedicated schizophrenic patients, the mean plasma GH level in rapid eye movement sleep was lower than during the waking stage, and the mean level of plasma cortisol was higher during the waking stage. Plasma cortisol levels did not differ between control subjects and patients at any time, but clozapine treatment decreased plasma cortisol levels at S2 compared with S1 and S3. Plasma GH levels were unchanged by clozapine treatment. Clozapine improved sleep continuity and increased stage 2 sleep time from the beginning of therapy. These effects were maintained through at least 7 weeks of therapy. However, clozapine did not affect the relationship of plasma GH and cortisol levels with sleep stages in schizophrenic patients.

Effects of antipsychotic drugs on cytokine networks

It has been known since the 1950s that phenothiazines have immunomodulatory effects. This review summarizes recent evidence suggesting that antipsychotic drugs, in particular chlorpromazine and the atypical compound clozapine, influence the production of cytokines. Cytokines, organized in networks of related peptides with pleiotropic functions, are pivotal humoral mediators of infection and inflammation, and they play an important role in hematopoiesis and autoimmunity. Therefore, the effects of antipsychotic drugs on cytokine networks are important for the understanding of immune-mediated side effects of these drugs, e.g. agranulocytosis. In addition, modulation of cytokine production by antipsychotic agents suggests that these drugs might be useful for the treatment of diseases which primarily involve the immune system. Moreover, because cytokines are known to have numerous effects on the CNS, they may mediate effects of antipsychotic drugs on brain functions. Finally, the influence of antipsychotic drugs on cytokine networks is an important confounding factor in studies investigating disease-related immunopathology in psychiatric disorders. This review provides a synopsis of the data published on these topics and outlines future research perspectives.

Effects of granulocyte colony-stimulating factor on night sleep in humans

Numerous animal studies suggest that cytokines such as interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) mediate increased sleep amount and intensity observed during infection and are, moreover, involved in physiological sleep regulation. In humans the role of cytokines in sleep-wake regulation is largely unknown. In a single-blind, placebo-controlled study, we investigated the effects of granulocyte colony-stimulating factor (G-CSF, 300 microgram sc) on the plasma levels of cytokines, soluble cytokine receptors, and hormones as well as on night sleep. G-CSF did not affect rectal temperature or the plasma levels of cortisol and growth hormone but did induce increases in the plasma levels of IL-1 receptor antagonist and both soluble TNF receptors within 2 h after injection. In parallel, the amount of slow-wave sleep and electroencephalographic delta power were reduced, indicating a lowered sleep intensity. We conclude that G-CSF suppresses sleep intensity via increased circulating amounts of endogenous antagonists of IL-1beta and TNF-alpha activity, suggesting that these cytokines are involved in human sleep regulation.