A rating scale for drug-induced akathisia has been derived that incorporates diagnostic criteria for pseudoakathisia, and mild, moderate, and severe akathisia. It comprises items for rating the observable, restless movements which characterise the condition, the subjective awareness of restlessness, and any distress associated with the akathisia. In addition, there is an item for rating global severity. A standard examination procedure is recommended. The inter-rater reliability for the scale items (Cohen's kappa) ranged from 0.738 to 0.955. Akathisia was found in eight of 42 schizophrenic in-patients, and nine had pseudoakathisia, where the typical sense of inner restlessness was not reported.

A rating scale for drug-induced akathisia

Sleep and schizophrenia: From epiphenomenon to treatable causal target

Sleep disturbances are commonly observed in schizophrenia, including in chronic, early-course, and first-episode patients. This has generated considerable interest, both in clinical and research endeavors, in characterizing the relationship between disturbed sleep and schizophrenia. Sleep features can be objectively assessed with EEG recordings. Traditionally, EEG studies have focused on sleep architecture, which includes non-REM and REM sleep stages. More recently, numerous studies have investigated alterations in sleep-specific rhythms, including EEG oscillations, such as sleep spindles and slow waves, in individuals with schizophrenia compared with control subjects. In this article, the author reviews state-of-the-art evidence of disturbed sleep in schizophrenia, starting from the relationship between sleep disturbances and clinical symptoms. First, the author presents studies demonstrating abnormalities in sleep architecture and sleep-oscillatory rhythms in schizophrenia and related psychotic disorders, with an emphasis on recent work demonstrating sleep spindles and slow-wave deficits in early-course and first-episode schizophrenia. Next, the author shows how these sleep abnormalities relate to the cognitive impairments in patients diagnosed with schizophrenia and point to dysfunctions in underlying thalamocortical circuits, Ca+ channel activity, and GABA-glutamate neurotransmission. Finally, the author discusses some of the next steps needed to further establish the role of altered sleep in schizophrenia, including the need to investigate sleep abnormalities across the psychotic spectrum and to establish their relationship with circadian disturbances, which in turn will contribute to the development of novel sleep-informed treatment interventions.

Sleep Abnormalities in Schizophrenia: State of the Art and Next Steps.

Circadian rhythm disruption, manifested as circadian misalignment, difficulty initiating sleep, and sleep-wake irregularity, is often left unrecognized in patients with schizophrenia. Studies have shown multiple adverse consequences of sleep irregularity, but limited data is available on schizophrenia. This is a secondary analysis of a case-control study of 66 schizophrenia patients with delayed sleep-wake phase (with or without meeting criteria for the disorder) and normal sleep-wake phase (mean age = 44.08 years; 45.45% males). Potential correlates included sleep quality, daytime sleepiness, social rhythms, chronotype, psychiatric symptoms, psychosocial functioning, metabolic index, cognitive function, and sociodemographic, lifestyle and pharmacological factors. Square successive difference (SSD) scores, derived from 1-week sleep diary and actigraphy, were indexes of sleep irregularity. Multilevel modeling analysis, with SSD scores as level-1 measures and the hypothesized correlates as level-2 measures, was performed. Statistical significance was Bonferroni-adjusted. Higher SSD scores of sleep diary and actigraphy variables were significantly associated with positive and depressive symptoms, poor sleep quality, daytime sleepiness, irregular social rhythm, evening chronotype, delayed sleep-wake phase disorder, later caffeine use and dinner time, greater cigarette use, and lower dosages of hypnotics and antipsychotics. Our findings highlight the implications of sleep irregularity in schizophrenia and the need for a multimodal intervention.

Correlates of sleep irregularity in schizophrenia

STUDY OBJECTIVES Sleep regularity predicts many health-related outcomes. Currently, however, there is no systematic approach to measuring sleep regularity. Traditionally, metrics have assessed deviations in sleep patterns from an individual's average; these traditional metrics include intra-individual standard deviation (StDev), interdaily stability (IS), and social jet lag (SJL). Two metrics were recently proposed that instead measure variability between consecutive days: composite phase deviation (CPD) and sleep regularity index (SRI). Using large-scale simulations, we investigated the theoretical properties of these five metrics. METHODS Multiple sleep-wake patterns were systematically simulated, including variability in daily sleep timing and/or duration. Average estimates and 95% confidence intervals were calculated for six scenarios that affect the measurement of sleep regularity: "scrambling" the order of days; daily vs. weekly variation; naps; awakenings; "all-nighters"; and length of study. RESULTS SJL measured weekly but not daily changes. Scrambling did not affect StDev or IS, but did affect CPD and SRI; these metrics, therefore, measure sleep regularity on multi-day and day-to-day timescales, respectively. StDev and CPD did not capture sleep fragmentation. IS and SRI behaved similarly in response to naps and awakenings but differed markedly for all-nighters. StDev and IS required over a week of sleep-wake data for unbiased estimates, whereas CPD and SRI required larger sample sizes to detect group differences. CONCLUSIONS Deciding which sleep regularity metric is most appropriate for a given study depends on a combination of the type of data gathered, the study length and sample size, and which aspects of sleep regularity are most pertinent to the research question.

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Measuring sleep regularity: theoretical properties and practical usage of existing metrics.

Subjective methods are often employed for sleep assessment due to their ease of use, but the results may not concur with objective findings. This discrepancy may be present in schizophrenia; howeve...

Yvonne Patricia Yuan-Ping Poon

Papers

Correlates of sleep irregularity in schizophrenia

Subjective-Objective Sleep Discrepancy in Schizophrenia.

Delayed sleep-wake phase disorder and delayed sleep-wake phase in schizophrenia: Clinical and functional correlates.