The effect of MElatonin on Depressive symptoms, Anxiety, CIrcadian and Sleep disturbances in patients after acute coronary syndrome (MEDACIS): study protocol for a randomized controlled trial

Combining cannabis and melatonin treatment with a rehabilitation program improved symptoms in a dog with compulsive disorder: A case report

Compulsive disorder in dogs (CD) is characterized by constant and time-consuming repetition of behaviors, emancipated from the environment, that definitely compromise their everyday life activities. Here, we documented the efficacy of a novel approach to counteract the negative symptoms of CD in a 5-year-old mongrel dog, previously found to be resistant to the conventional antidepressant. The patient underwent an integrated and interdisciplinary approach, based on the cannabis and melatonin co-administration, together with a tailored 5-month-lasting behavioral program. Observational findings showed a lower rate of compulsive episodes and better management of the dog as well, when compared to the previous paroxetine treatment. We followed him for an additional four months of therapy, and the owners reported easier management of the dog, as reduction of abnormal behaviors to a level acceptable to the owners. Overall, our data so far collected in the CD dog may allow us to test more deeply the feasibility and safety of such an off-label approach, at both preclinical and clinical levels.

The Case for the Patient-Centric Development of Novel Digital Sleep Assessment Tools in Major Depressive Disorder

Background

Depression imposes a major burden on public health as the leading cause of disability worldwide. Sleep disturbance is a core symptom of depression that affects the vast majority of patients. Nonetheless, it is frequently not resolved by depression treatment and may even be worsened through some pharmaceutical interventions. Disturbed sleep negatively impact patients' quality of life, and persistent sleep disturbance increases the risk of recurrence, relapse, and even suicide. However, the development of novel treatments that might improve sleep problems is hindered by the lack of reliable low-burden objective measures that can adequately assess disturbed sleep in this population.

Summary

Developing improved digital measurement tools that are fit for use in clinical trials for major depressive disorder could promote the inclusion of sleep as a focus for treatment, clinical drug development, and research. This perspective piece explores the path toward the development of novel digital measures, reviews the existing evidence on the meaningfulness of sleep in depression, and summarizes existing methods of sleep assessments, including the use of digital health technologies.

Key Messages

Our objective was to make a clear call to action and path forward for the qualification of new digital outcome measures which would enable assessment of sleep disturbance as an aspect of health that truly matters to patients, promoting sleep as an important outcome for clinical development, and ultimately ensure that disturbed sleep will not remain the forgotten symptom of depression.

The Role of Inflammation in the Pathophysiology of Depression and Suicidal Behavior: Implications for Treatment

Depression and suicidal behavior are 2 complex psychiatric conditions of significant public health concerns due to their debilitating nature. The need to enhance contemporary treatments and preventative approaches for these illnesses not only calls for distillation of current views on their pathogenesis but also provides an impetus for further elucidation of their novel etiological determinants. In this regard, inflammation has recently been recognized as a potentially important contributor to the development of depression and suicidal behavior. This review highlights key evidence that supports the presence of dysregulated neurometabolic and immunologic signaling and abnormal interaction with microbial species as putative etiological hallmarks of inflammation in depression as well as their contribution to the development of suicidal behavior. Furthermore, therapeutic insights addressing candidate mechanisms of pathological inflammation in these disorders are proposed.

Night shift hormone: How does melatonin affect depression?

Melatonin is the main hormone secreted by the pineal gland that modulates the circadian rhythm and mood. Previous studies have shown the therapeutic effects of melatonin, or its important analogue, agomelatine, on depression. In this review study, we aimed to discuss the potential mechanisms of melatonin involved in the treatment of depression. It was noted that disrupted circadian rhythm can lead to depressive state, and melatonin via regulating circadian rhythm shows a therapeutic effect. It was also noted that melatonin induces antidepressant effects via promoting antioxidant system and neurogenesis, and suppressing oxidative stress, neuroinflammation, and apoptosis. The interaction effect between melatonin or agomelatine and serotonergic signaling has a significant effect on depression. It was noted that the psychotropic effects of agomelatine are induced by the synergistic interaction between melatonin and 5-HT_2C receptors. Agomelatine also interacts with glutamatergic signaling in brain regions involved in regulating mood and circadian rhythm. Interestingly, it was concluded that melatonin exerts both pro- and anti-inflammatory effects, depending on the grade of inflammation. It was suggested that synergistic interaction between melatonin and 5-HT_2C receptors may be able to induce therapeutic effects on other psychiatric disorders. Furthermore, dualistic role of melatonin in regulating inflammation is an important point that can be examined at different levels of inflammation in animal models of depression.

The roles of the circadian hormone melatonin in drug addiction

Given the devastating social and health consequences of drug addiction and the limitations of current treatments, a new strategy is needed. Circadian system disruptions are frequently associated with drug addiction. Correcting abnormal circadian rhythms and improving sleep quality may thus be beneficial in the treatment of patients with drug addiction. Melatonin, an essential circadian hormone that modulates the biological clock, has anti-inflammatory, analgesic, anti-depressive, and neuroprotective effects via gut microbiota regulation and epigenetic modifications. It has attracted scientists' attention as a potential solution to drug abuse. This review summarized scientific evidence on the roles of melatonin in substance use disorders at the cellular, circuitry, and system levels, and discussed its potential applications as an intervention strategy for drug addiction.

Safety of higher doses of melatonin in adults: A systematic review and meta-analysis

Melatonin is commonly used for sleep and jetlag at low doses. However, there is less documentation on the safety of higher doses, which are being increasingly used for a wide variety of conditions, including more recently COVID-19 prevention and treatment. The aim of this review was to investigate the safety of higher doses of melatonin in adults. Medline, Scopus, Embase and PsycINFO databases from inception until December 2019 with convenience searches until October 2020. Randomised controlled trials investigating high-dose melatonin (≥10 mg) in human adults over 30 years of age were included. Two investigators independently abstracted articles using PRISMA guidelines. Risk of bias was assessed by a committee of three investigators. 79 studies were identified with a total of 3861 participants. Studies included a large range of medical conditions. The meta-analysis was pooled data using a random effects model. The outcomes examined were the number of adverse events (AEs), serious adverse events (SAEs) and withdrawals due to AEs. A total of 29 studies (37%) made no mention of the presence or absence of AEs. Overall, only four studies met the pre-specified low risk of bias criteria for meta-analysis. In that small subset, melatonin did not cause a detectable increase in SAEs (Rate Ratio = 0.88 [0.52, 1.50], p = .64) or withdrawals due to AEs (0.93 [0.24, 3.56], p = .92), but did appear to increase the risk of AEs such as drowsiness, headache and dizziness (1.40 [1.15, 1.69], p < .001). Overall, there has been limited AE reporting from high-dose melatonin studies. Based on this limited evidence, melatonin appears to have a good safety profile. Better safety reporting in future long-term trials is needed to confirm this as our confidence limits were very wide due to the paucity of suitable data.

Associations between Melatonin, Neuroinflammation, and Brain Alterations in Depression

Pro-inflammatory systemic conditions that can cause neuroinflammation and subsequent alterations in brain regions involved in emotional regulation have been suggested as an underlying mechanism for the pathophysiology of major depressive disorder (MDD). A prominent feature of MDD is disruption of circadian rhythms, of which melatonin is considered a key moderator, and alterations in the melatonin system have been implicated in MDD. Melatonin is involved in immune system regulation and has been shown to possess anti-inflammatory properties in inflammatory conditions, through both immunological and non-immunological actions. Melatonin has been suggested as a highly cytoprotective and neuroprotective substance and shown to stimulate all stages of neuroplasticity in animal models. The ability of melatonin to suppress inflammatory responses through immunological and non-immunological actions, thus influencing neuroinflammation and neurotoxicity, along with subsequent alterations in brain regions that are implicated in depression, can be demonstrated by the antidepressant-like effects of melatonin. Further studies that investigate the associations between melatonin, immune markers, and alterations in the brain structure and function in patients with depression could identify potential MDD biomarkers.

Antidepressant actions of melatonin and melatonin receptor agonist: Focus on pathophysiology and treatment

Depression has become one of the most commonly prevalent neuropsychiatric disorders, and the main characteristics of depression are sleep disorders and melatonin secretion disorders caused by circadian rhythm disorders. Abnormal endogenous melatonin alterations can contribute to the occurrence and development of depression. However, molecular mechanisms underlying this abnormality remain ambiguous. The present review summarizes the mechanisms underlying the antidepressant effects of melatonin, which is related to its functions in the regulation of the hypothalamic-pituitary-adrenal axis, inhibition of neuroinflammation, inhibition of oxidative stress, alleviation of autophagy, and upregulation of neurotrophic, promotion of neuroplasticity and upregulation of the levels of neurotransmitters, etc. Also, melatonin receptor agonists, such as agomelatine, ramelteon, piromelatine, tasimelteon, and GW117, have received considerable critical attention and are highly implicated in treating depression and comorbid disorders. This review focuses on melatonin and various melatonin receptor agonists in the pathophysiology and treatment of depression, aiming to provide further insight into the pathogenesis of depression and explore potential targets for novel agent development.

Regulatory aspects and evidences of melatonin use for sleep disorders and insomnia: an integrative review

BACKGROUND

Insomnia is a sleep disorder characterized by difficulty of falling asleep or maintaining sleep, which affects different age groups. Currently, melatonin is used as a therapeutic treatment in cases of insomnia in children, adults, and elderly people.

OBJECTIVE

To evaluate the effectiveness of melatonin in sleep disorders, its dosage, potential adverse effects, as well as labeling laws and regulations in Brazil.

METHODS

This integrative review was carried out using the Cochrane Library, Medline (Pubmed), and Science Direct databases. Twenty-five articles and three documents available on the Brazilian Society of Endocrinology and Metabology (SBEM) and National Health Surveillance Agency (ANVISA) websites published between 2015 and 2020 were selected to be evaluated in full.

RESULTS

It was found that in most of the selected articles the use of melatonin reduces sleep latency. The effective melatonin doses varied according to each age group, from 0.5 to 3 mg in children, 3 to 5 mg in adolescents, 1 to 5 mg in adults, and 1 to 6 mg in elderly people. Side effects are mild when taking usual doses. In Brazil, no registered drug and current regulation on the use and marketing of melatonin has been identified.

CONCLUSION

The use of melatonin is an alternative therapy that can be used for sleeping disorders. According to the evidences found, it did not demonstrate toxicity or severe side effects, nor dependence even when administered at high doses, suggesting that it is a safe medication to treat patients of different ages suffering from sleeping disorders.

External validity of randomized clinical trial studying preventing depressive symptoms following acute coronary syndrome

OBJECTIVE

The objective of the current study was to quantitatively explore aspects of external validity, both researcher's choices (eligibility) and patient's choices (consent), of a recently conducted clinical trial.

METHODS

A cohesive comparison between the MEDACIS trial (NCT02451293) database and a national quality and research database was conducted. Comparisons between both participants and nonconsenting patients (patient consent) and participants and noneligible patients (researcher selection) were performed. Comparisons of outcomes were depressive and anxiety symptoms, demographics, and somatic or psychiatric comorbidity.

RESULTS

Noneligible patients had significantly higher levels of depressive symptoms and anxiety and were older and more likely to suffer from unstable angina pectoris. Furthermore, noneligible patients were less likely to be married, had a lower educational level, used more medication, and had a higher frequency of comorbidity. Nonconsenting patients had significantly higher levels of depressive symptoms and anxiety and were older and more likely to be females compared to participants.

CONCLUSION

Significant differences were present between noneligible patients and participants; however, more troublingly significant differences were shown between nonconsenting patients and participants. The presence of depressive symptoms and anxiety has a significant impact on patients' willingness to give informed consent in clinical trials in cardiology with a focus on psychological outcomes.

Zebrafish as a tool in the study of sleep and memory-related disorders

Sleep is an evolutionarily conserved phenomenon, being an essential biological necessity for the learning process and memory consolidation. The brain displays two types of electrical activity during sleep: slow-wave activity or non-rapid eye movement (NREM) sleep and desynchronized brain wave activity or rapid eye movement (REM) sleep. There are many theories about "Why we need to sleep?" among them the synaptic homeostasis. This theory proposes that the role of sleep is the restoration of synaptic homeostasis, which is destabilized by synaptic strengthening triggered by learning during waking and by synaptogenesis during development. Sleep diminishes the plasticity load on neurons and other cells to normalize synaptic strength. In contrast, it re-establishes neuronal selectivity and the ability to learn, leading to the consolidation and integration of memories. The use of zebrafish as a tool to assess sleep and its disorders is growing, although sleep in this animal is not yet divided, for example, into REM and NREM states. However, zebrafish are known to have a regulated daytime circadian rhythm. Their sleep state is characterized by periods of inactivity accompanied by an increase in arousal threshold, preference for resting place, and the "rebound sleep effect" phenomenon, which causes an increased slow-wave activity after a forced waking period. In addition, drugs known to modulate sleep, such as melatonin, nootropics, and nicotine, have been tested in zebrafish. In this review, we discuss the use of zebrafish as a model to investigate sleep mechanisms and their regulation, demonstrating this species as a promising model for sleep research.

Prevention of depression in adults with long-term physical conditions

BACKGROUND

Major depression is one of the world's leading causes of disability in adults with long-term physical conditions compared to those without physical illness. This co-morbidity is associated with a negative prognosis in terms of increased morbidity and mortality rates, increased healthcare costs, decreased adherence to treatment regimens, and a substantial decline in quality of life. Therefore, preventing the onset of depressive episodes in adults with long-term physical conditions should be a global healthcare aim. In this review, primary or tertiary (in cases of preventing recurrences in those with a history of depression) prevention are the focus. While primary prevention aims at preventing the onset of depression, tertiary prevention comprises both preventing recurrences and prohibiting relapses. Tertiary prevention aims to address a depressive episode that might still be present, is about to subside, or has recently resolved. We included tertiary prevention in the case where the focus was preventing the onset of depression in those with a history of depression (preventing recurrences) but excluded it if it specifically focused on maintaining an condition or implementing rehabilitation services (relapse prevention). Secondary prevention of depression seeks to prevent the progression of depressive symptoms by early detection and treatment and may therefore be considered a 'treatment,' rather than prevention. We therefore exclude the whole spectrum of secondary prevention.

OBJECTIVES

To assess the effectiveness, acceptability and tolerability of psychological or pharmacological interventions, in comparison to control conditions, in preventing depression in adults with long-term physical conditions; either before first ever onset of depressive symptoms (i.e. primary prevention) or before first onset of depressive symptoms in patients with a history of depression (i.e. tertiary prevention).

SEARCH METHODS

We searched the Cochrane Common Mental Disorders Controlled Trials Register, CENTRAL, MEDLINE, Embase, PsycINFO and two trials registries, up to 6 February 2020.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of preventive psychological or pharmacological interventions, specifically targeting incidence of depression in comparison to treatment as usual (TAU), waiting list, attention/psychological placebo, or placebo. Participants had to be age 18 years or older, with at least one long-term physical condition, and no diagnosis of major depression at baseline (primary prevention). In addition, we included studies comprising mixed samples of patients with and without a history of depression, which explored tertiary prevention of recurrent depression. We excluded other tertiary prevention studies. We also excluded secondary preventive interventions. Primary outcomes included incidence of depression, tolerability, and acceptability. Secondary outcomes included severity of depression, cost-effectiveness and cost-utility.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 11 RCTs, with one trial on psychological interventions, and 10 trials on pharmacological interventions. Data analyses on the psychological intervention (problem-solving therapy compared to TAU) included 194 participants with age-related macular degeneration. Data analyses on pharmacological interventions included 837 participants comparing citalopram (one trial), escitalopram (three trials), a mixed sample of fluoxetine/nortriptyline (one trial), melatonin (one trial), milnacipran (one trial), and sertraline (three trials), each to placebo. Included types of long-term physical conditions were acute coronary syndrome (one trial), breast cancer (one trial), head and neck cancer (two trials), stroke (five trials), and traumatic brain injury (one trial). Psychological interventions Very low-certainty evidence of one study suggests that problem solving therapy may be slightly more effective than TAU in preventing the incidence of depression, immediately post-intervention (odds ratio (OR) 0.43, 95% confidence interval (CI) 0.20 to 0.95; 194 participants). However, there may be little to no difference between groups at six months follow-up (OR 0.71, 95% CI 0.36 to 1.38; 190 participants; one study; very low-certainty evidence). No data were available regarding incidence of depression after six months. Regarding acceptability (drop-outs due to any cause), slightly fewer drop-outs occurred in the TAU group immediately post-intervention (OR 5.21, 95% CI 1.11 to 24.40; 206 participants; low-certainty evidence). After six months, however, the groups did not differ (OR 1.67, 95% CI 0.58 to 4.77; 206 participants; low-certainty evidence). This study did not measure tolerability. Pharmacological interventions Post-intervention, compared to placebo, antidepressants may be beneficial in preventing depression in adults with different types of long-term physical conditions, but the evidence is very uncertain (OR 0.31, 95% CI 0.20 to 0.49; 814 participants; nine studies; I2 =0%; very low-certainty evidence). There may be little to no difference between groups both immediately and at six months follow-up (OR 0.44, 95% CI 0.08 to 2.46; 23 participants; one study; very low-certainty evidence) as well as at six to 12 months follow-up (OR 0.81, 95% CI 0.23 to 2.82; 233 participants; three studies; I2 = 49%; very low-certainty evidence). There was very low-certainty evidence from five studies regarding the tolerability of the pharmacological intervention. A total of 669 adverse events were observed in 316 participants from the pharmacological intervention group, and 610 adverse events from 311 participants in the placebo group. There was very low-certainty evidence that drop-outs due to adverse events may be less frequent in the placebo group (OR 2.05, 95% CI 1.07 to 3.89; 561 participants; five studies; I2 = 0%). There was also very low-certainty evidence that drop-outs due to any cause may not differ between groups either post-intervention (OR 1.13, 95% CI 0.73 to 1.73; 962 participants; nine studies; I2 = 28%), or at six to 12 months (OR 1.13, 95% CI 0.69 to 1.86; 327 participants; three studies; I2 = 0%).

AUTHORS' CONCLUSIONS

Based on evidence of very low certainty, our results may indicate the benefit of pharmacological interventions, during or directly after preventive treatment. Few trials examined short-term outcomes up to six months, nor the follow-up effects at six to 12 months, with studies suffering from great numbers of drop-outs and inconclusive results. Generalisation of results is limited as study populations and treatment regimes were very heterogeneous. Based on the results of this review, we conclude that for adults with long-term physical conditions, there is only very uncertain evidence regarding the implementation of any primary preventive interventions (psychological/pharmacological) for depression.

The effect of melatonin on depressive symptoms and anxiety in patients after acute coronary syndrome: The MEDACIS randomized clinical trial

BACKGROUND

Depression following acute coronary syndrome is prevalent and associated with increased mortality and morbidity. Melatonin may function as a primary prophylactic antidepressant substance and alleviate depressive symptoms. The study was undertaken to determine if melatonin administered following an acute coronary syndrome (ACS) could prevent development of depression.

METHODS

The study was a double-blinded, placebo-controlled, multicenter, randomized clinical trial performed in five primary care cardiology departments at Zealand, Denmark. Included patients were adults patients, free of depression at baseline, included at the latest 4 weeks after acute coronary syndrome. Twenty-five mg melatonin or placebo was administered 1 h before participants' bedtime for 12 weeks. The primary outcome is Major Depression Inventory (MDI) measured every two weeks throughout the trial. Incidence of depression was apriori defined as MDI score ≥ 21 during the trial. Reported exploratory outcomes were patterns of dropout and safety outcomes.

RESULTS

1220 patients were screened and 252 participants were randomized in a 1:1 ratio. Baseline MDI score in the melatonin and placebo group were, respectively, 6.18 (CI 5.32-7.05) and 5.98 (CI 5.19-6.77). No significant intergroup differences were found during the study in the intention-to-treat analysis or per-protocol analysis. Cumulative events of depressive episodes during the 12 weeks were six in the melatonin group and four in the placebo group. A significant drop in depressive symptoms were present throughout the study period. No intergroup differences were present in dropouts or adverse events.

CONCLUSIONS

Melatonin showed no prophylactic antidepressant effect following acute coronary syndrome. The non-significant results might be due to a type II error or melatonin might not be able to prevent development of depressive symptoms following ACS.

The effect of melatonin on endothelial dysfunction in patients after acute coronary syndrome: The MEFACS randomized clinical trial

Endothelial dysfunction (ED) precedes acute coronary syndrome. Oxidative stress results in ED but is reversible. Melatonin is aside from being a circadian hormone, also an antioxidant. The aim of this study was to investigate whether 25 mg melatonin administered for twelve weeks following acute coronary syndrome (ACS) could improve ED. In this placebo-controlled randomized trial, ED was measured as reactive hyperemia index (RHI) at baseline, day 14, and day 84. The effect was assessed using a generalized estimating equation adjusted for the baseline RHI. As secondary outcome, the concentrations of three biomarkers were measured: l-arginine, asymmetric dimethylarginine, and uric acid. Thirty-one patients were included in the study. The intention-to-treat analysis of the primary outcome had 26 patients due to missing data. The estimated marginal mean difference in RHI at day 14 and day 84 between the groups was 0.15 (95% CI: 0.29-0.01, P = .039) in favor of the placebo group. No significant differences in the biomarker concentrations were found. Melatonin treatment after ACS did not improve but may have aggravated ED. The significant difference between groups was in favor of placebo, but this might be due to the effect of missing data or uneven distribution of comorbidities.

Cardioprotective Melatonin: Translating from Proof-of-Concept Studies to Therapeutic Use

In this review we summarized the actual clinical data for a cardioprotective therapeutic role of melatonin, listed melatonin and its agonists in different stages of development, and evaluated the melatonin cardiovascular target tractability and prediction using machine learning on ChEMBL. To date, most clinical trials investigating a cardioprotective therapeutic role of melatonin are in phase 2a. Selective melatonin receptor agonists Tasimelteon, Ramelteon, and combined melatonergic-serotonin Agomelatine, and other agonists with registered structures in CHEMBL were not yet investigated as cardioprotective or cardiovascular drugs. As drug-able for these therapeutic targets, melatonin receptor agonists have the benefit over melatonin of well-characterized pharmacologic profiles and extensive safety data. Recent reports of the X-ray crystal structures of MT1 and MT2 receptors shall lead to the development of highly selective melatonin receptor agonists. Predictive models using machine learning could help to identify cardiovascular targets for melatonin. Selecting ChEMBL scores > 4.5 in cardiovascular assays, and melatonin scores > 4, we obtained 284 records from 162 cardiovascular assays carried out with 80 molecules with predicted or measured melatonin activity. Melatonin activities (agonistic or antagonistic) found in these experimental cardiovascular assays and models include arrhythmias, coronary and large vessel contractility, and hypertension. Preclinical proof-of-concept and early clinical studies (phase 2a) suggest a cardioprotective benefit from melatonin in various heart diseases. However, larger phase 3 randomized interventional studies are necessary to establish melatonin and its agonists’ actions as cardioprotective therapeutic agents.

Circadian modulation of neuroplasticity by melatonin: a target in the treatment of depression

Mood disorders are a spectrum of neuropsychiatric disorders characterized by changes in the emotional state. In particular, major depressive disorder is expected to have a worldwide prevalence of 20% in 2020, representing a huge socio-economic burden. Currently used antidepressant drugs have poor efficacy with only 30% of the patients in remission after the first line of treatment. Importantly, mood disorder patients present uncoupling of circadian rhythms. In this regard, melatonin (5-methoxy-N-acetyltryptamine), an indolamine synthesized by the pineal gland during the night, contributes to synchronization of body rhythms with the environmental light/dark cycle. In this review, we describe evidence supporting antidepressant-like actions of melatonin related to the circadian modulation of neuroplastic changes in the hippocampus. We also present evidence for the role of melatonin receptors and their signalling pathways underlying modulatory effects in neuroplasticity. Finally, we briefly discuss the detrimental consequences of circadian disruption on neuroplasticity and mood disorders, due to the modern human lifestyle. Together, data suggest that melatonin's stimulation of neurogenesis and neuronal differentiation is beneficial to patients with mood disorders. LINKED ARTICLES: This article is part of a themed section on Recent Developments in Research of Melatonin and its Potential Therapeutic Applications. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.16/issuetoc.