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Query: UMLS:C0036341 (schizophrenia)
 60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Schizophrenia is characterized by disturbed sleep architecture. It has been thought that sleep abnormalities may underlie information processing deficits associated with this disorder. Nonlinear analyses of sleep data can provide valuable information on sleep characteristics that may be relevant to the functions of sleep. This study examined the predictability and nonlinear complexity of sleep EEG time series in two EEG channels (C4 and F4) using measures of nonlinearity, such as symbolic dynamics and the largest Lyapunov exponent (LLE) in schizophrenia. A series of antipsychotic naive patients with first episode of schizophrenia or schizoaffective disorder and age-matched healthy controls were studied during awake period, stage 1/2, slow wave sleep (stage 3/4) and rapid eye movement (REM) sleep. Nonlinearity scores were significantly lower during awake stage in patients compared to controls suggesting that there may be a diminished interplay between various parameters for the genesis of waking EEG. Symbolic dynamics and LLE were significantly lower in patients during REM compared to healthy controls, suggesting decreased nonlinear complexity of the EEG time series and diminished chaos in schizophrenia. Decreased nonlinear complexity was also correlated with neurocognitive deficits as assessed by the Wisconsin card sorting test. Diminished complexity of EEG time series during awake and REM sleep in patients with schizophrenia may underlie the impaired ability to process information in psychotic disorders such as schizophrenia.
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PMID:Decreased nonlinear complexity and chaos during sleep in first episode schizophrenia: a preliminary report. 1547 97

The differential diagnosis of narcolepsy versus schizophrenia is sometimes complicated by similar phenomenology, particularly when hallucinations predominate. REM sleep disturbances seem fundamental in the pathophysiology of narcolepsy, and REM sleep intrusions during periods of wakefulness are often associated with hallucinations also in healthy controls and in patients with other brain disorders including schizophrenia. This study used a semistructured interview to investigate different aspects of hallucinations (frequency, modality, content, and dependence on body posture) in 148 patients with narcolepsy, 21 patients with acute exacerbation of a schizophrenic disorder, and 128 healthy subjects. About 80% of patients with narcolepsy, 81% of schizophrenics, and 37% of healthy subjects reported lifetime occurrence of hallucinations (at least once). Auditory hallucinations were reported by 81% of schizophrenic patients (narcoleptics 45%, healthy controls 9%), whereas 83% of narcoleptic patients reported visual hallucinations (schizophrenics 29%, healthy controls 19%). Kinetic hallucinations were experienced by 71% of patients with narcolepsy and 53% of healthy controls in contrast to only 5% of schizophrenics. Accordingly, the content of hallucinations differed substantially between the groups. Most hallucinations in narcoleptics but not in schizophrenics, were sleep-related and dependent on body posture. Taken together, the qualitative aspects of hallucinations in narcolepsy and schizophrenia were so different that a common underlying mechanism of hallucinations in the two conditions is unlikely. Although the clinical separation of patients with narcolepsy and schizophrenia with predominant hallucinations is sometimes difficult, clinical features including the patient's illness history, and careful psychopathological assessments can help to avoid misdiagnoses and treatment failures.
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PMID:Narcoleptic and schizophrenic hallucinations. Implications for differential diagnosis and pathophysiology. 1560 61

Patients with schizophrenia often suffer from sleep disturbances such as excessive sleeping and insomnia. Common medications for schizophrenia can have a sedative effect on patients. Not all antipsychotic medications have the same sedative effect, which is related to dosage and affinity for histamine H1 receptors. Studies have shown that, compared with conventional antipsychotics, atypical antipsychotics such as risperidone, olanzapine, quetiapine, and ziprasidone generally cause less sedation yet are as effective in controlling psychosis and agitation. Sedation can be troublesome to patients who are trying to become re-integrated into society and interfere with their treatment regimen. Both persistent sedation and chronic insomnia can be managed by the physician.
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PMID:Atypical antipsychotics: sleep, sedation, and efficacy. 1600 Oct 94

Sleep disturbances in psychiatric disease have long been reported. However, research on sleep disturbances in child and adolescent psychiatric disorders is limited. We examined the relationship of sleep disturbance to clinical severity and co-morbid diagnoses (e.g. anxiety), for a population with childhood-onset schizophrenia (COS). Sixty-one COS patients underwent a medication-free inpatient observation period as part of an NIMH study of COS. Sleep quantity during the last 5-7 days of a patient's medication-free period was measured using safety records and daily nursing notes. Subjects were divided into two groups: "good sleepers" (>6 h) and "poor sleepers" (<6 h) based on the average of total hours slept per night. Comparisons between groups were made with respect to clinical ratings at both admission and during washout period, co-morbid diagnosis of generalized anxiety disorder (GAD) and a susceptibility gene (G72) for COS. The median average sleep score for the entire group was 6.1 (S.D.=2.01) h. The good and poor sleep groups differed significantly in terms of severity of positive symptoms (SAPS) and negative symptoms at admission (SANS) both on admission and during the medication-free period. There was no significant relationship between G72 genotypes and a past and/or present diagnosis of GAD. COS patients suffer from significant sleep disturbances and the sleep disturbance is highly related to the symptom severity. As there are numerous health implications of poor sleep, clinicians should have a low threshold for treating sleep disturbances in this population.
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PMID:Sleep disturbances in childhood-onset schizophrenia. 1673 Sep 52

Dopamine depletion is involved in the pathophysiology of Parkinson's disease, whereas hyperdopaminergia may play a fundamental role in generating endophenotypes associated with schizophrenia. Sleep disturbances are known to occur in both schizophrenia and Parkinson's disease, suggesting that dopamine plays a role in regulating the sleep-wake cycle. Here, we show that novelty-exposed hyperdopaminergic mice enter a novel awake state characterized by spectral patterns of hippocampal local field potentials that resemble electrophysiological activity observed during rapid-eye-movement (REM) sleep. Treatment with haloperidol, a D2 dopamine receptor antagonist, reduces this abnormal intrusion of REM-like activity during wakefulness. Conversely, mice acutely depleted of dopamine enter a different novel awake state characterized by spectral patterns of hippocampal local field potentials that resemble electrophysiological activity observed during slow-wave sleep (SWS). This dopamine-depleted state is marked by an apparent suppression of SWS and a complete suppression of REM sleep. Treatment with D2 (but not D1) dopamine receptor agonists recovers REM sleep in these mice. Altogether, these results indicate that dopamine regulates the generation of sleep-wake states. We propose that psychosis and the sleep disturbances experienced by Parkinsonian patients result from dopamine-mediated disturbances of REM sleep.
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PMID:Dopaminergic control of sleep-wake states. 1703 44

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.
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PMID:Sleep in schizophrenia: impairments, correlates, and treatment. 1711 80

Animal models are a promising method to approach the basic mechanisms of the neurobiological disturbances encountered in mental disorders. Depression is characterized by a decrease of REM sleep latency and an increase of rapid eye movement density. In schizophrenia, electrophysiological, tomographic, pharmacological and neurochemical activities are all encountered during REM sleep. Mental retardation and dementia are characterized by rather specific REM sleep disturbances. Identification of the genetic support for these abnormalities (endophenotypes) encountered during REM sleep could help to develop specific treatments.
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PMID:The neurobiological characteristics of rapid eye movement (REM) sleep are candidate endophenotypes of depression, schizophrenia, mental retardation and dementia. 1735 Jul 44

Fast synaptic inhibition in the brain and spinal cord is mediated largely by ionotropic gamma-aminobutyric acid (GABA) receptors. GABAA receptors play a key role in controlling neuronal activity; thus modulating their function will have important consequences for neuronal excitation. GABAA receptors are important therapeutic targets for a range of sedative, anxiolytic, and hypnotic agents and are involved in a number of CNS diseases, including sleep disturbances, anxiety, premenstrual syndrome, alcoholism, muscle spasms, Alzheimer's disease, chronic pain, schizophrenia, bipolar affective disorders, and epilepsy. This review focuses on the functional and pharmacological properties of GABAA receptors and trafficking as an essential mechanism underlying the dynamic regulation of synaptic strength.
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PMID:GABAA receptors: properties and trafficking. 1736 82

Many patients with schizophrenia or bipolar disorder experience disturbances in their sleep-wake cycle, which may be a result of the disorder itself, of pharmacotherapy, or of a comorbid sleep disorder. These sleep disruptions can seriously impair patients' functioning as well as their quality of life. Therefore, accurate assessment of sleep problems is essential to appropriately treat patients and promote symptomatic remission. Sedating antipsychotics may ameliorate sleep disturbances, as well as agitation or other behavioral emergencies; however, these agents may also sedate patients to the point of dissatisfaction with the medication and/or impaired functioning, which may, in turn, increase treatment noncompliance and nonadherence. Using short-term adjunctive medications, such as benzo-diazepines or hypnotic agents, with a nonsedating antipsychotic to alleviate sleep disturbances is a reasonable treatment option for patients with schizophrenia or bipolar disorder. Overall, the pharma-cokinetics and pharmacodynamics of atypical antipsychotics are important factors to consider in the risk-benefit analysis, as are dosing strategies and individual patient factors, and clinicians must decide which agents are most appropriate for which patients.
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PMID:Atypical antipsychotics: sedation versus efficacy. 1848 5

Modafinil is a wake-promoting agent that is pharmacologically different from other stimulants. It has been investigated in healthy volunteers, and in individuals with clinical disorders associated with excessive sleepiness, fatigue, impaired cognition and other symptoms. This review examines the use of modafinil in clinical practice based on the results of randomized, double-blind, placebo-controlled clinical trials available in the English language in the MEDLINE database. In sleep-deprived individuals, modafinil improves mood, fatigue, sleepiness and cognition to a similar extent as caffeine but has a longer duration of action. Evidence for improved cognition in non-sleep-deprived healthy volunteers is controversial.Modafinil improves excessive sleepiness and illness severity in all three disorders for which it has been approved by the US FDA, i.e. narcolepsy, shift-work sleep disorder and obstructive sleep apnoea with residual excessive sleepiness despite optimal use of continuous positive airway pressure (CPAP). However, its effects on safety on the job and on morbidities associated with these disorders have not been ascertained. Continued use of CPAP in obstructive sleep apnoea is essential. Modafinil does not benefit cataplexy.In very small, short-term trials, modafinil improved excessive sleepiness in patients with myotonic dystrophy. It was efficacious in fairly large studies of attention deficit hyperactivity disorder (ADHD) in children and adolescents, and was as efficacious as methylphenidate in a small trial, but has not been approved by the FDA, in part because of its serious dermatological toxicity. In a trial of 21 non-concurrent subjects, with 2-week treatment periods, modafinil was as effective as dexamfetamine in adult ADHD. Modafinil was helpful for depressive symptoms in bipolar disorder in a trial that excluded patients with stimulant-induced mania. A single dose of modafinil may hasten recovery from general anaesthesia after day surgery. A single dose of modafinil improved the ability of emergency room physicians to attend didactic lectures after a night shift, but did not improve their ability to drive home and caused sleep disturbances subsequently.Modafinil had a substantial placebo effect on outcomes such as fatigue, excessive sleepiness and depression in patients with traumatic brain injury, major depressive disorder, schizophrenia, post-polio fatigue and multiple sclerosis; however, it did not provide any benefit greater than placebo.Trials of modafinil for excessive sleepiness in Parkinson's disease, cocaine addiction and cognition in chronic fatigue syndrome provided inconsistent results; all studies had extremely small sample sizes. Modafinil cannot be recommended for these conditions until definitive data become available.Modafinil induces and inhibits several cytochrome P450 isoenzymes and has the potential for interacting with drugs from all classes. The modafinil dose should be reduced in the elderly and in patients with hepatic disease. Caution is needed in patients with severe renal insufficiency because of substantial increases in levels of modafinil acid. Common adverse events with modafinil include insomnia, headache, nausea, nervousness and hypertension. Decreased appetite, weight loss and serious dermatological have been reported with greater frequency in children and adolescents, probably due to the higher doses (based on bodyweight) used. Modafinil may have some abuse/addictive potential although no cases have been reported to date.
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PMID:Approved and investigational uses of modafinil : an evidence-based review. 1872 34


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