Physical Activity, Sleep-related Behaviors and Severity of Symptoms in Schizophrenia

Neuroligin-2 shapes individual slow waves during slow-wave sleep and the response to sleep deprivation in mice

BACKGROUND

Sleep disturbances are a common comorbidity to most neurodevelopmental disorders and tend to worsen disease symptomatology. It is thus crucial to understand mechanisms underlying sleep disturbances to improve patients' quality of life. Neuroligin-2 (NLGN2) is a synaptic adhesion protein regulating GABAergic transmission. It has been linked to autism spectrum disorders and schizophrenia in humans, and deregulations of its expression were shown to cause epileptic-like hypersynchronized cerebral activity in rodents. Importantly, the absence of Nlgn2 (knockout: KO) was previously shown to alter sleep-wake duration and quality in mice, notably increasing slow-wave sleep (SWS) delta activity (1-4 Hz) and altering its 24-h dynamics. This type of brain oscillation is involved in memory consolidation, and is also a marker of homeostatic sleep pressure. Sleep deprivation (SD) is notably known to impair cognition and the physiological response to sleep loss involves GABAergic transmission.

METHODS

Using electrocorticographic (ECoG) recordings, we here first aimed to verify how individual slow wave (SW; 0.5-4 Hz) density and properties (e.g., amplitude, slope, frequency) contribute to the higher SWS delta activity and altered 24-h dynamics observed in Nlgn2 KO mice. We further investigated the response of these animals to SD. Finally, we tested whether sleep loss affects the gene expression of Nlgn2 and related GABAergic transcripts in the cerebral cortex of wild-type mice using RNA sequencing.

RESULTS

Our results show that Nlgn2 KO mice have both greater SW amplitude and density, and that SW density is the main property contributing to the altered 24-h dynamics. We also found the absence of Nlgn2 to accelerate paradoxical sleep recovery following SD, together with profound alterations in ECoG activity across vigilance states. Sleep loss, however, did not modify the 24-h distribution of the hypersynchronized ECoG events observed in these mice. Finally, RNA sequencing confirmed an overall decrease in cortical expression of Nlgn2 and related GABAergic transcripts following SD in wild-type mice.

CONCLUSIONS

This work brings further insight into potential mechanisms of sleep duration and quality deregulation in neurodevelopmental disorders, notably involving NLGN2 and GABAergic neurotransmission.

Body dissatisfaction, negative affect, and engagement in healthy behaviors: The conditional effect of future-self continuity

The relationship between body dissatisfaction and negative affect is complex, with some research suggesting that this combination motivates individuals to engage in more health-related behaviors; while other studies find it increases unhealthy behavior. To bridge this gap, it may be the case that to the extent these individuals have continuity between their present and future selves, the more likely they are able to make positive health-related choices with this future self in mind. We examined individuals (n = 344; 51.74% men) aged between 18 and 72 years (M = 39.66, SD = 11.49) who endorsed high negative affect along with body dissatisfaction but either had high or low levels of future self-continuity. We found individuals experiencing body dissatisfaction and negative affect reported higher engagement in healthy behaviors only if they had a strong connection to their future self, index of moderated mediation = 0.07 (95% CI = 0.02, 0.13). These findings support targeting future-self continuity in therapeutic regimens to bolster engagement in healthy behaviors among individuals with body dissatisfaction and high negative affect.

Glycogen Synthase Kinase-3 Inhibitors: Preclinical and Clinical Focus on CNS-A Decade Onward

The protein kinase, GSK-3, participates in diverse biological processes and is now recognized a promising drug discovery target in treating multiple pathological conditions. Over the last decade, a range of newly developed GSK-3 inhibitors of diverse chemotypes and inhibition modes has been developed. Even more conspicuous is the dramatic increase in the indications that were tested from mood and behavior disorders, autism and cognitive disabilities, to neurodegeneration, brain injury and pain. Indeed, clinical and pre-clinical studies were largely expanded uncovering new mechanisms and novel insights into the contribution of GSK-3 to neurodegeneration and central nerve system (CNS)-related disorders. In this review we summarize new developments in the field and describe the use of GSK-3 inhibitors in the variety of CNS disorders. This remarkable volume of information being generated undoubtedly reflects the great interest, as well as the intense hope, in developing potent and safe GSK-3 inhibitors in clinical practice.

Physical activity levels associated with insomnia and depressive symptoms in middle-aged and elderly patients with chronic schizophrenia

BACKGROUND

Previous evidence suggested that physical activity had beneficial effects on psychopathological symptoms, insomnia, or depressive symptoms in people with schizophrenia. This study investigated the association between physical activity levels and insomnia and depressive symptoms in middle-aged and elderly hospitalized patients with chronic schizophrenia (CS).

METHODS

179 participants were enrolled. We used the 30-item Positive and Negative Syndrome Scale (PANSS_-30) to assess the psychopathological symptoms. We used the Insomnia Severity Index scale (ISI) and 17-item Hamilton Depression Scale (HAMD-17) to evaluate insomnia and depressive symptoms. Daily physical activity time less than 30 min, within 30-60 min, and more than 60 min were defined as physical inactivity, moderate physical activity, and vigorous physical activity, respectively. The Chi-square test, analysis of variance (ANOVA), and Mann-Whitney U-test were applied for categorical, continuous, and non-normal distribution variables, respectively. The Pearson or Spearman's correlation analyses were utilized to examine the association between physical activity levels, ISI total scores, HAMD total scores, and socio-demographic and clinical variables. Finally, socio-demographic variables with a P-value < 0.05 in the comparison between insomnia/depressive group and non-insomnia/depressive group were considered for inclusion in binary logistic regression analysis to determine the relationship between physical activity levels and insomnia or depressive symptoms.

RESULTS

The ISI total scores (r = -0.247, P = 0.001) and HAMD total scores (r = -0.312, P < 0.001) were negatively correlated with physical activity levels. Logistic regression analysis revealed that older age, higher depressive factor scores, and lower physical activity level were influential factors of insomnia symptoms in CS patients (P < 0.05). In addition, vigorous physical activity (compared with physical inactivity) and higher negative and depressive factor scores were independently associated with depressive symptoms in CS patients (P < 0.05).

CONCLUSION

Physical activity levels were influential factors in comorbid insomnia and depressive symptoms in CS patients. Given the benefits of physical activity, it should be strengthened as a routine adjunct to clinical treatment or psychiatric care so as to improve the physical and mental health of patients with psychiatric symptoms.

Recommendations of the schizophrenia expert center network for the screening prevention and treatment of sleep disorders based on the results from the real-world schizophrenia FACE-SZ national cohort

BACKGROUND

Sleep disorders associated factors are under explored in schizophrenia while the literature suggests high and heterogeneous frequency.

AIMS

The objective of the present study was to determine the prevalence and risk factors of sleep disorders in the real-world FACE-SZ national cohort.

METHOD

Stabilized schizophrenic outpatients were recruited in 10 expert centers for schizophrenia. Sleep quality was explored with the Pittsburgh Sleep Quality Index (PSQI) and sleep disorders was defined by a PSQI score > 5. Psychosis severity was measured with the Positive and Negative Syndrome Scale, current major depressive episode with the Calgary Depression Scale for Schizophrenia, verbal aggressiveness with the Buss-Perry Aggression Questionnaire, adherence to treatment with the Medication Adherence Rating Scale, akathisia with the Barnes Akathisia Scale. Current somatic comorbidities and body mass index were reported. Variables with P values <0.20 in univariate analysis were included in a multivariate regression model.

RESULTS

Of the 562 included patients, 327 subjects (58.2%, IC95% [54.1% - 62.3%]) reported having sleep disorders. After adjustment, sleep disorders were significantly associated with migraine (adjusted odds ratio aOR = 2.23, p = 0.041), major depressive disorder (aOR 1.79, p = 0.030), poor adherence to treatment (aOR = 0.87, p = 0.006), akathisia (aOR = 1.29, p = 0.042) and verbal aggressiveness (aOR = 1.09, p = 0.002).

CONCLUSIONS

More than one on two stabilized real-life outpatients with schizophrenia have been identified with sleep disorders. Combined with the literature data, we have yielded expert recommendations for the treatment and prevention of sleep disorders including treating undiagnosed comorbid depression and migraine and managing antipsychotic treatment to improve adherence and akathisia.