High-quality remission: potential benefits of the melatonergic approach for patients with major depressive disorder

The Therapeutic Effect of Exogenous Melatonin on Depressive Symptoms: A Systematic Review and Meta-Analysis

BACKGROUND

Depression-related mortality and morbidity pose growing public health burdens worldwide. Although the therapeutic effect of exogenous melatonin on depression has been investigated, findings remain inconsistent. We conducted this systematic review and meta-analysis to clarify the effectiveness of melatonin in the treatment of depression, including primary and secondary depression symptoms.

METHODS

We searched the online databases of PubMed, EMBASE, and the Cochrane Library for original studies published up to May 2021. We used STATA 14.0 software to synthesize the results of included studies. To evaluate the effectiveness of melatonin, we calculated the standardized mean differences (SMDs) and 95% confidence intervals (CIs) of depression scores between the melatonin and placebo groups.

RESULTS

Our literature search returned 754 publications, among which 19 studies with 1,178 patients (715 women, 463 men; mean age: 56.77 years) met inclusion criteria. Melatonin dosages ranged from 2 to 25 mg per day; treatment durations were between 10 days and 3.5 years. Our synthesized results showed that melatonin was not found significantly beneficial for alleviating depressive symptoms (SMD = -0.17, 95% CI = [-0.38, 0.05]). Subgroup analysis demonstrated that the decrease in depression scores measured with the Beck Depression Inventory (BDI) was significant (SMD = -0.52, 95% CI = [-0.73, -0.31]).

CONCLUSIONS

There is very limited evidence for effects of melatonin on depression.

Plasma levels of 3-methoxy-4-hydroxyphenylglycol levels, number of hospitalization and cognitive function predicts the cognitive effect of atypical antipsychotic monotherapy in patients with acute schizophrenia

Although the effects of atypical antipsychotics with regard to improving neurocognitive function are not sufficiently high. The present study applied an atypical antipsychotic monotherapy for patients with acute schizophrenia to (1) examine the percentage of patients who respond well to this treatment, (2) explore the factors that predict response (e.g. the improvement of neurocognition), and (3) identify the factors associated with improved neurocognitive function. We studied 40 patients with acute schizophrenia who had received atypical antipsychotic monotherapy for 24 weeks. The following parameters were evaluated at baseline and 24 weeks after the start of treatment: psychotic symptoms, neurocognitive function, and blood biological markers including homovanillic acid, 3-methoxy-4-hydroxyphenylglycol, and brain-derived neurotrophic factor. Marked improvements in neurocognitive function were noted in 7.5%-25% of patients. The factors that significantly predicted neurocognitive function improvement were the frequency of hospitalization (verbal memory and verbal fluency), 3-methoxy-4-hydroxyphenylglycol (verbal fluency and executive function), and verbal memory (working memory). Approximately 20% of the patients showed good response to treatment with antipsychotics. Frequency of hospitalization, 3-methoxy-4-hydroxyphenylglycol level, and other parameters predicted responsiveness to these drug therapies. Thus, it might be useful to apply these factors to predict responses to treatment.

Brain-derived neurotrophic factor serum and plasma levels in the treatment of acute schizophrenia with olanzapine or risperidone: 6-week prospective study

Antipsychotics have been the mainstay of the treatment of schizophrenia, and their potential role in neuroprotection could be related to brain-derived neurotrophic factor (BDNF). So far different effects on both serum and plasma levels of BDNF were reported related to the various antipsychotic treatments. Aim of this study was to investigate the influence of olanzapine or risperidone on both plasma and serum levels of BDNF in patients with acute schizophrenia. For 50 participants with acute episode of schizophrenia both plasma and serum BDNF, along with the Positive and Negative Syndrome Scale (PANSS) and the Clinical Global Impression scale, were assessed pretreatment and post treatment - after 6 weeks of either risperidone or olanzapine. Results show that a weak correlation between pretreatment plasma and serum levels of BNDF was found no longer significant after 6 weeks of treatment. Antipsychotics, olanzapine and risperidone showed no significant effect on post treatment plasma and serum levels of BDNF. Pretreatment plasma level of BDNF and PANSS positive subscale were positively correlated. Post treatment serum level of BDNF and Clinical Global Impression were negatively correlated. In conclusion, plasma and serum BDNF levels could be different markers to some extent with regard to clinical symptoms, response to therapy and outcome. The interrelation between serum and plasma BDNF should be established in further studies.

Relationships between serum brain-derived neurotrophic factor, plasma catecholamine metabolites, cytokines, cognitive function and clinical symptoms in Japanese patients with chronic schizophrenia treated with atypical antipsychotic monotherapy

OBJECTIVES

Catecholamines, brain-derived neurotrophic factor (BDNF) and cytokines may be involved in the pathophysiology of schizophrenia. The aim of this study was to examine the associations between serum BDNF levels, plasma catecholamine metablolites, cytokines and the cognitive functions of patients with schizophrenia treated with atypical antipsychotic monotherapy.

METHODS

One hundred and forty-six patients with schizophrenia and 51 age- and sex-matched healthy controls were examined for peripheral biological markers and neurocognitive test.

RESULTS

There were positive correlations between serum BDNF levels and scores for verbal memory and attention and processing speed as well as between serum BDNF levels and negative symptoms. Furthermore, there was a negative correlation between the plasma homovanillic acid (HVA) level and motor function and a positive correlation between the plasma 3-methoxy-4-hydroxyphenylglycol (MHPG) level and attention and processing speed. There were no significant correlations between interleukin-6 or tumour necrosis factor alpha and cognitive function. Moreover, there were no significant correlations between the plasma levels of HVA, MHPG, cytokines and clinical symptoms.

CONCLUSIONS

Serum BDNF levels are positively related to the impairment of verbal memory and attention, plasma HVA levels are positively related to motor function, and plasma MHPG levels are positively related to attention in patients with schizophrenia.

Peripheral brain-derived neurotrophic factor in schizophrenia and the role of antipsychotics: meta-analysis and implications

It has been postulated that schizophrenia (SZ) is related to a lower expression of brain-derived neurotrophic factor (BDNF). In the past few years, an increasing number of divergent clinical studies assessing BDNF in serum and plasma have been published. It is now possible to verify the relationship between BDNF levels and severity of symptoms in SZ as well as the effects of antipsychotic drugs on BDNF using meta-analysis. The aims of this study were to verify if peripheral BDNF is decreased in SZ, whether its levels are correlated with positive and negative symptomatology and if BDNF levels change after antipsychotic treatment. This report consists of two distinct meta-analyses of peripheral BDNF in SZ including a total of 41 studies and more than 7000 participants: (1) peripheral BDNF levels in serum and plasma were moderately reduced in SZ compared with controls. Notably, this decrease was accentuated with the disease duration. However, the extent of peripheral BDNF level decrease did not correlate with the severity of positive and negative symptoms. (2) In plasma, but not serum, peripheral BDNF levels are consistently increased after antipsychotic treatment irrespective of the patient's response to medication. In conclusion, there is compelling evidence that there are decreased levels of peripheral BDNF in SZ, in parallel to previously described reduced cerebral BDNF expression. It remains unclear whether these systemic changes are causally related to the development of SZ or if they are merely a pathologic epiphenomenon.

Use of translational pharmacodynamic biomarkers in early-phase clinical studies for schizophrenia

Schizophrenia is a severe mental disorder characterized by cognitive deficits, and positive and negative symptoms. The development of effective pharmacological compounds for the treatment of schizophrenia has proven challenging and costly, with many compounds failing during clinical trials. Many failures occur due to disease heterogeneity and lack of predictive preclinical models and biomarkers that readily translate to humans during early characterization of novel antipsychotic compounds. Traditional early-phase trials consist of single- or multiple-dose designs aimed at determining the safety and tolerability of an investigational compound in healthy volunteers. However, by incorporating a translational approach employing methodologies derived from preclinical studies, such as EEG measures and imaging, into the traditional Phase I program, critical information regarding a compound's dose-response effects on pharmacodynamic biomarkers can be acquired. Furthermore, combined with the use of patients with stable schizophrenia in early-phase clinical trials, significant 'de-risking' and more confident 'go/no-go' decisions are possible.

Brain-derived neurotrophic factor levels in schizophrenia: a systematic review with meta-analysis

Brain-derived neurotrophic factor (BDNF) regulates the survival and growth of neurons, and influences synaptic efficiency and plasticity. Several studies report reduced peripheral (blood) levels of BDNF in schizophrenia, but findings are inconsistent. We undertook the first systematic review with meta-analysis of studies examining blood BDNF levels in schizophrenia compared with healthy controls, and examined potential effects of age, gender and medication. Included are individual studies of BDNF blood (serum or plasma) levels in schizophrenia (including schizoaffective disorder, or first episode psychosis), compared with age-matched healthy controls, obtained by electronic Medline and Embase searches, and hand searching. The decision to include or exclude studies, data extraction and quality assessment were completed by two independent reviewers. The initial search revealed 378 records, of which 342 were excluded on reading the Abstract, because they did not examine BDNF blood levels in schizophrenia compared with healthy controls. Of 36 papers screened in full, 17 were eligible for inclusion, but one was subsequently removed as an outlier. The remaining 16 studies provided moderate quality evidence of reduced blood BDNF levels in schizophrenia (Hedges g=-0.458, 95% confidence interval=-0.770 to -0.146, P<0.004, random effects model). Subgroup analyses reveal reduced BDNF in both drug-naïve and medicated patients, and in males and females with schizophrenia. Meta-regressions showed an association between reduced BDNF in schizophrenia and increasing age, but no effects of medication dosage. Overall, blood levels of BDNF are reduced in medicated and drug-naïve patients with schizophrenia; this evidence is of moderate quality, that is, precise but with considerable, unexplained heterogeneity across study results.

Clinical effectiveness, construct and assessment

BACKGROUND

In an era of contention about the efficacy of antidepressants, the concept of clinical effectiveness has surfaced as a basic tenet of real-world practice. The concept of clinical effectiveness can lead to important insights into the treatment of depression and, by acting as an organizing concept for research, can help studies better focus on obtaining information necessary to improve clinical practice.

METHODS

The limitations and strengths of efficacy and effectiveness studies in psychiatry are explored, and recent effectiveness studies in psychiatry are discussed, and their implications for re-examining treatment goals and remission.

RESULTS

Efficacy studies are invaluable for the development of new drugs, but often lack generalizability. In contrast, effectiveness studies are broader in scope and offer the potential to assess quality of life and functional change. Studies that explore the clinical effectiveness of treatments for depression can identify important treatment gaps and suggest ways to address them. Although the efficacy of an antidepressant is important, other factors such as patient adherence, safety and tolerability, and the alignment of treatment outcomes with dimensions likely to be critical to patients (quality of life and functioning) also need to be examined.

CONCLUSIONS

Antidepressant treatment, both in clinical practice and in research, should involve clinical considerations that go beyond efficacy data. Broader issues of tolerability, safety, residual symptoms, functioning, and quality of life must also be addressed. Accomplishing this objective may involve the development of new global effectiveness measures; better outcome measures; and a broader, more patient-centered orientation towards clinical care.

Brain-derived neurotrophic factor: findings in schizophrenia

PURPOSE OF REVIEW

To review the role of brain-derived neurotrophic factor (BDNF) in neuroplasticity related to schizophrenia and the recent findings that have been reported on the status of BDNF in patients with schizophrenia and its association with the clinical measures.

RECENT FINDINGS

Peripheral BDNF levels have been found altered in first-episode patients with psychosis and also in chronic schizophrenia patients. A few studies have reported changes in peripheral BDNF levels following antipsychotic treatment. The role of Val66Met polymorphism in BDNF has been shown to play an important role in structural and functional plasticity in schizophrenia.

SUMMARY

Although peripheral BDNF levels hold promise for providing new perspectives for the development of novel therapeutic strategies for the treatment of schizophrenia, additional studies including efforts to prove its potential as a biomarker are warranted.

Predictive factors for responding to sertraline treatment: views from plasma catecholamine metabolites and serotonin transporter polymorphism

In the present study, we investigated the effects of sertraline on plasma levels of 3-methoxy-4-hydroxyphenylglycol (MHPG), homovanillic acid (HVA), and serum brain-derived neurotrophic factor (BDNF) levels in 59 depressed patients treated with sertraline. We also examined the relationship between the dynamics of the catecholamine metabolites, BDNF, serotonin transporter-linked polymorphic region (5-HTTLPR) gene polymorphism (long and short alleles), and the clinical response to sertraline. The extent of clinical improvement was evaluated using the 17-item Hamilton Rating Scale for Depression (Ham-D) before and 8 weeks after treatment with sertraline. Responders were defined as showing at least a 50% decrease in the Ham-D score. Baseline plasma HVA levels of responders to sertraline treatment were significantly lower than those of non-responders (p = 0.02). In addition, a positive correlation was identified between changes in plasma HVA levels and the rate of response to sertraline treatment (p = 0.001). A trend toward higher baseline serum BDNF levels was found in responders compared with non-responders (p = 0.095). In addition, serum BDNF levels were slightly increased (not significant) in responders (p = 0.058), but not in non-responders. Responders had a higher short-allele genotype frequency in the 5-HTTLPR for the promoter region than did non-responders (p = 0.037). These results suggest that pre-treatment plasma HVA levels and the 5-HTTLPR genotype for the promoter might be associated with a response to sertraline.

Cytochrome P450 testing for prescribing antipsychotics in adults with schizophrenia: systematic review and meta-analyses

There is wide variability in the response of individuals to standard doses of antipsychotic drugs. It has been suggested that this may be partly explained by differences in the cytochrome P450 (CYP450) enzyme system responsible for metabolizing the drugs. We conducted a systematic review and meta-analyses to consider whether testing for CYP450 single nucleotide polymorphisms in adults starting antipsychotic treatment for schizophrenia predicts and leads to improvements in clinical outcomes. High analytic validity in terms of sensitivity and specificity was seen in studies reporting P450 testing. However, there was limited evidence of the role of CYP2D6 polymorphisms in antipsychotic efficacy, although there was an association between CYP2D6 genotype and extrapyramidal adverse effects. No studies reported on the prospective use of CYP2D6 genotyping tests in clinical practice. In conclusion, evidence of clinical validity and utility of CYP2D6 testing in patients being prescribed antipsychotics is lacking, and thus, routine pharmacogenetic testing prior to antipsychotic prescription cannot be supported at present. Further research is required to improve the evidence base and to generate data on clinical validity and clinical utility.

Increase in brain-derived neurotrophic factor in first episode psychotic patients after treatment with atypical antipsychotics

Some preclinical and postmortem studies suggest that the effects of atypical antipsychotics could be mediated by brain-derived neurotrophic factor (BDNF). Olanzapine is an atypical antipsychotic with shown efficacy in psychosis treatment. The aim of this study was to compare plasma BDNF levels at baseline and after 1 year of olanzapine treatment in 18 drug-naive patients who experienced a first psychotic episode with those of 18 healthy control participants matched by age, sex, and socioeconomic level. Plasma BDNF levels were measured in patients at the index episode and at 1, 6, and 12 months of follow-up using an enzyme-linked immunosorbent assay. Symptoms and functioning of patients and controls were assessed with the Positive and Negative Symptom Scale and Global Assessment of Function Scale. BDNF levels of patients at onset were significantly lower than controls but increased toward control values during olanzapine treatment. There was a significant positive correlation between BDNF levels and functioning (Global Assessment of Function Scale). BDNF levels were also negatively correlated with positive symptoms, but not with negative symptoms or general psychopathology. Results suggest that olanzapine can offset the low BDNF levels at the onset of first psychotic episodes, and improving psychotic symptoms. The increase in BDNF levels may be its mechanism of action in improving positive symptoms.

A randomized double-blind placebo-controlled trial of treatment as usual plus exogenous slow-release melatonin (6 mg) or placebo for sleep disturbance and depressed mood

Sleep disturbance is common in major depressive disorder (MDD), and is often characterized by early-morning waking. Melatonin is a hypnotic and synchronizes circadian rhythms. It may also be an antidepressant. The melatonin agonists, ramelteon and agomelatine, have hypnotic and antidepressant properties, but there is a dearth of trials investigating the use of melatonin in MDD. This randomized, controlled trial aimed to determine whether exogenous melatonin is a sleep promoter and antidepressant. Thirty-three participants with a Diagnostic and Statistical Manual of Mental Disorders (fourth edition) diagnosis of MDD and early-morning waking were selected for a 4-week, randomized, double-blind trial of slow-release melatonin (6 mg; vs. placebo) given at bedtime over 4 weeks. Sleep was measured subjectively using sleep diaries and the Leeds Sleep Evaluation Questionnaire and objectively using wrist actigraphy. Of the 33 participants, 31 completed the trial. General Linear Modelling showed significant improvements in depression and sleep over time, but this was not specific to melatonin. However, there was a trend towards an improvement in mood with melatonin, and no adverse side effects were observed. In conclusion, melatonin may be beneficial for treating MDD, it seems to be safe and well tolerated, but its potential for treating depression in people who do not wish to take antidepressants requires further evaluation.

Different patterns of longitudinal changes in plasma levels of catecholamine metabolites and brain-derived neurotrophic factor after administration of atypical antipsychotics in first episode untreated schizophrenic patients

In the present study, we longitudinally investigated the effects of risperidone, olanzapine, and aripiprazole on plasma levels of catecholamine metabolites and brain-derived neurotrophic factor (BDNF) in first-episode unmedicated schizophrenic patients. The subjects were 59 Japanese schizophrenic patients (35 males and 24 females; age range: 18-46 years; mean+/-SD: 25+/-16 years). The patients were treated with risperidone (n=32) in a dose range of 2-6 mg/day (mean+/-SD=3.4+/-1.9), olanzapine (n=18) in a dose range of 5-20 mg/day (mean+/-SD=12.1+/-5.8), or aripiprazole (n=9) in a dose range of 12-30 mg/day (mean+/-SD=22.8+/-10.1). All three drugs significantly decreased plasma homovanillic acid (HVA) levels within 8 weeks, although aripiprazole transiently raised this level before 8 weeks. All three drugs also significantly increased plasma 3-methoxy-4-hydroxyphenylglycol (MHPG) levels within 8 weeks. On the other hand, none of them altered plasma BDNF levels. These results indicate that risperidone, olanzapine, and aripiprazole affect catecholaminergic systems in the brain, that the effects of aripiprazole on the dopaminergic systems seem to slightly different than those of risperidone and olanzapine, and that these atypical antipsychotic drugs might not alter BDNF levels, at least within 8 weeks of treatment.

Serum brain-derived neurotrophic factor levels as a novel biological marker for the activities of psychiatric symptoms in systemic lupus erythematosus

OBJECTIVES

Neuropsychiatric systemic lupus erythematosus (NPSLE) is a serious but potentially treatable disease. However, biological markers such as IgG index or IL-6 do not always reflect the severity of the psychotic symptoms of NPSLE. We hypothesized that serum BDNF levels may be a biological marker for reflecting the severity of the psychiatric symptoms of NPSLE.

METHODS

The participants enrolled in this study were 28 healthy volunteers and 54 Japanese SLE inpatients at the University Hospital of Occupational and Environmental Health, all of whom fulfilled the criteria for the classification of SLE. SLE patients were divided into the three groups: NPSLE with psychiatric symptoms including an acute confusional state, anxiety disorder, cognitive dysfunction, mood disorder, and psychosis (NP group); NPSLE without psychiatric symptoms (NN group); and SLE without neuropsychiatric symptoms (S group). The serum BDNF levels were measured by ELISA.

RESULTS

Serum BDNF levels were significantly increased in the NP group (mean +/- SE = 37.0 +/- 5.46 ng/ml) compared with those in the other three groups (NN group; mean +/- SE = 9.1 +/- 2.44 ng/ml, P < 0.0001, S group; mean +/- SE = 10.4 +/- 2.51 ng/ml, P < 0.0001, healthy control; mean +/- SE = 11.44 +/- 0.69, P < 0.0001). Subsequently, serum BDNF levels were decreased in parallel with the improvement of psychiatric symptoms in the NP group.

CONCLUSION

These results suggest that serum BDNF is a biological marker for the severity of psychiatric symptoms in NPSLE patients.

Reduced serum BDNF levels in patients with chronic schizophrenic disorder in relapse, who were treated with typical or atypical antipsychotics

Brain-derived neurotrophic factor signals and dopaminergic function in the brain are strongly associated, and research on BDNF in schizophrenia may enhance our insights on the pathophysiological mechanisms of this disease. In the present study we aimed to investigate the possible association between serum BDNF levels and schizophrenic relapses and the possible differential effects of treatment with typical and atypical antipsychotics on serum BDNF levels in the same group of patients. We measured serum BDNF levels in 47 patients with schizophrenia during a relapse and again 6 weeks after administration of antipsychotic treatment (14 on risperidone, 18 on haloperidol, 10 on olanzapine and five on amisulpride) and in 44 healthy volunteers. Patients with schizophrenia showed reduced serum BDNF levels in relation to healthy volunteers at study entry. No significant differences were revealed in BDNF serum levels after 6 weeks of antipsychotic treatment in the patients compared to their own levels at study entry. However, serum BDNF was significantly increased in the subgroup receiving olanzapine compared to the other antipsychotics. Our findings may indicate a differential effect of olanzapine on BDNF levels compared to haloperidol, risperidone, and amisulpride.

The mononuclear phagocyte system and its cytokine inflammatory networks in schizophrenia and bipolar disorder

This review describes patients with schizophrenia and bipolar disorder. In such patients, a high inflammatory set point of circulating monocytes at the transcriptome level is observed, involving various inflammatory transcripts forming distinct fingerprints (the transcriptomic monocyte fingerprint in schizophrenia overlaps with that in bipolar disorder, but also differs with it at points). There are increased levels of compounds of the IL-1, IL-6 and TNF system in the serum (be it modest and inconsistent). There is also evidence that the IL-2 system is activated in patients with schizophrenia (and perhaps those with mania), although independently of the activation of the IL-1, IL-6 and TNF systems, suggesting separate inducing mechanisms for monocyte and T-cell activation. It is not yet known whether such T cell activation involves the Th1/Th2/Th17 or Treg systems.

Agomelatine, a melatonin agonist with antidepressant properties

Agomelatine (beta-methyl-6-chloromelatonin), which is structurally homologous to melatonin, is a potent agonist of melatonin MT1 and MT2 receptors as well as an antagonist of serotonin 5-HT(2C) receptors. Agomelatine appears to improve sleep without causing daytime sedation. It has not been found to be associated with sexual side effects and discontinuation symptoms. Three placebo-controlled trials, one of them a dose finding study and two of them pivotal trials, suggest that agomelatine is an antidepressant at doses of 25 - 50 mg/day. Agomelatine appears to be well tolerated, without sexual or cardiac adverse effects, weight gain or discontinuation syndromes. Animal studies suggest a possible neuroprotective action of agomelatine, although there are more data in favor of an anxiolytic effect. Substantially more research is needed to establish its role in the treatment of mood and circadian rhythm disorders.

Association study of interleukin 2 (IL2) and IL4 with schizophrenia in a Japanese population

Interleukin 2 (IL-2) and IL-4 are pleiotropic cytokines regulating Th1/Th2 balance and have a regulatory activity in brain function. Thus these cytokines have been implicated in the pathophysiology of schizophrenia. The latest studies provided controversial results regarding the genetic associations of these cytokines. The functional polymorphisms, IL2-330T/G and IL4-590C/T, were associated with schizophrenia in a German population, although contradictory findings were also reported in a Korean population. To ascertain whether IL2 and IL4 contribute to vulnerability to schizophrenia, we conducted a moderate-scale case-control (536 patients and 510 controls) association study for seven polymorphisms in Japanese subjects. There were no significant associations of these genes with schizophrenia using either single marker or haplotype analyses. The present study suggests that IL2 and IL4 do not contribute to vulnerability to schizophrenia in the Japanese population.

Brain-derived neurotropic factor/TrkB signaling in the pathogenesis and novel pharmacotherapy of schizophrenia

The role of neurotropins, predominantly brain-derived neurotropic factor (BDNF), has been implicated in the pathophysiology as well as treatment outcome of schizophrenia. Both human and rodent studies indicate that the beneficial effects of antipsychotic drugs are mediated, at least in part, through BDNF and its receptor, TrkB. This review will discuss the available data on the levels of BDNF and TrkB in subjects with schizophrenia and in animals with and without conventional antipsychotics. The data concerning the impact of the antipsychotic drugs on BDNF/TrkB signaling will also be discussed. More importantly, this review will provide future perspective on BDNF/TrkB signaling as a novel molecular target to correct the pathogenesis and improve the long-term clinical outcome by treatments with conventional and adjunctive drugs.