Eszopiclone stimulates the hypothalamo-pituitary-adrenal axis in the rat

Pharmacotherapeutic management of insomnia and effects on sleep processes, neural plasticity, and brain systems modulating stress: A narrative review

Introduction

Insomnia is a stress-related sleep disorder, may favor a state of allostatic overload impairing brain neuroplasticity, stress immune and endocrine pathways, and may contribute to mental and physical disorders. In this framework, assessing and targeting insomnia is of importance.

Aim

Since maladaptive neuroplasticity and allostatic overload are hypothesized to be related to GABAergic alterations, compounds targeting GABA may play a key role. Accordingly, the aim of this review was to discuss the effect of GABAA receptor agonists, short-medium acting hypnotic benzodiazepines and the so called Z-drugs, at a molecular level.

Method

Literature searches were done according to PRISMA guidelines. Several combinations of terms were used such as “hypnotic benzodiazepines” or “brotizolam,” or “lormetazepam” or “temazepam” or “triazolam” or “zolpidem” or “zopiclone” or “zaleplon” or “eszopiclone” and “insomnia” and “effects on sleep” and “effect on brain plasticity” and “effect on stress system”. Given the complexity and heterogeneity of existing literature, we ended up with a narrative review.

Results

Among short-medium acting compounds, triazolam has been the most studied and may regulate the stress system at central and peripheral levels. Among Z-drugs eszopiclone may regulate the stress system. Some compounds may produce more “physiological” sleep such as brotizolam, triazolam, and eszopiclone and probably may not impair sleep processes and related neural plasticity. In particular, triazolam, eszopiclone, and zaleplon studied in vivo in animal models did not alter neuroplasticity.

Conclusion

Current models of insomnia may lead us to revise the way in which we use hypnotic compounds in clinical practice. Specifically, compounds should target sleep processes, the stress system, and sustain neural plasticity. In this framework, among the short/medium acting hypnotic benzodiazepines, triazolam has been the most studied compound while among the Z-drugs eszopiclone has demonstrated interesting effects. Both offer potential new insight for treating insomnia.

Basal Cortisol Levels Are Increased in Patients with Mild Cognitive Impairment: Role of Insomnia and Short Sleep Duration

BACKGROUND

Mild cognitive impairment (MCI) is frequent in elderly and a risk factor for dementia. Both insomnia and increased cortisol levels are risk factors for MCI.

OBJECTIVE

We examined cross-sectionally whether increased cortisol levels are associated with short sleep duration (SSD) and/or the insomnia short sleep duration (ISS) phenotype, in elderly with MCI.

METHODS

One hundred twenty-four participants with MCI and 84 cognitively non-impaired controls (CNI)≥60 years underwent medical history, physical examination, neuropsychiatric evaluation, neuropsychological testing, 3-day actigraphy, assessment of subjective insomnia symptoms, and a single morning plasma cortisol level. The short sleep phenotypes were defined by sleep efficiency below the median of the entire sample (i.e.,≤81%) with at least one insomnia symptom (ISS) or without (SSD). ANOVA models were used to compare the various sleep phenotypes to those who did not present either short sleep or insomnia symptoms [non-insomnia (NI)].

RESULTS

MCI participants had higher cortisol levels compared to the CNI group (p = 0.009). MCI participants with insomnia (n = 44) or SSD (n = 38) had higher cortisol levels compared to the NI group (n = 42; p = 0.014 and p = 0.045, respectively). Furthermore, MCI participants with ISS phenotype but not those with insomnia with normal sleep duration had higher cortisol levels compared to NI (p = 0.011 and p = 0.4, respectively). Both linear trend analyses showed that cortisol reached the highest levels in the ISS phenotype.

CONCLUSION

The ISS and SSD phenotypes are associated with increased cortisol levels in elderly with MCI. Improving sleep quality and duration and decreasing cortisol levels may delay further cognitive decline.

Effects of trazodone versus cognitive behavioral therapy in the insomnia with short sleep duration phenotype: a preliminary study

STUDY OBJECTIVES

The insomnia with objective short sleep duration phenotype is associated with increased risk for adverse health outcomes, physiological hyperarousal, and a blunted response to cognitive behavioral therapy for insomnia (CBT-I). Whether insomnia with objective short sleep duration responds better to pharmacological treatment compared to CBT-I has not been examined.

METHODS

Participants included 15 patients with chronic insomnia (86.7% female), aged 45.3 ± 8.1 years. Eight patients were randomized to CBT-I and 7 to trazodone. Patients were examined with 2 weeks of actigraphy, salivary cortisol, and the insomnia severity index at 3 time points (pretreatment, 3-month posttreatment, and 6-month follow-up). Mixed between-within-subjects analysis of variance and univariate analysis of covariance were conducted to assess the impact of trazodone and CBT-I on patients' total sleep time, salivary cortisol, and insomnia severity index scores across the 3 time points.

RESULTS

Trazodone, but not CBT-I, significantly lengthened total sleep time (when measured with actigraphy) both at posttreatment (51.01 minutes vs -11.73 minutes; P = .051; Cohen's d = 1.383) and at follow-up (50.35 minutes vs -7.56 minutes; P = .012; Cohen's d = 1.725), respectively. In addition, trazodone, but not CBT-I, showed a clinically meaningful decrease in salivary cortisol from pretreatment to posttreatment (-36.07% vs -11.70%; Cohen's d = 0.793) and from pretreatment to follow-up (-21.37% vs -5.79%; Cohen's d = 0.284), respectively. Finally, there were no differences on insomnia severity index scores between the trazodone and the CBT-I groups.

CONCLUSIONS

The current preliminary, open-label, randomized trial suggests that trazodone, but not CBT-I, significantly improves objective sleep duration and reduces hypothalamic-pituitary-adrenal axis activation, suggesting a differential treatment response in the insomnia with objective short sleep duration phenotype.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Name: Study of Trazodone & Cognitive Behavioral Therapy to Treat Insomnia; URL: https://clinicaltrials.gov/ct2/show/NCT01348542; Identifier: NCT01348542.