A randomized, double-blind, placebo-controlled, proof-of-concept trial of creatine monohydrate as adjunctive treatment for bipolar depression

Nutraceuticals in Psychiatric Disorders: A Systematic Review

Correct nutrition and diet are directly correlated with mental health, functions of the immune system, and gut microbiota composition. Diets with a high content of some nutrients, such as fibers, phytochemicals, and short-chain fatty acids (omega-3 fatty acids), seem to have an anti-inflammatory and protective action on the nervous system. Among nutraceuticals, supplementation of probiotics and omega-3 fatty acids plays a role in improving symptoms of several mental disorders. In this review, we collect data on the efficacy of nutraceuticals in patients with schizophrenia, autism spectrum disorders, major depression, bipolar disorder, and personality disorders. This narrative review aims to provide an overview of recent evidence obtained on this topic, pointing out the direction for future research.

Non-canonical pathways in the pathophysiology and therapeutics of bipolar disorder

Bipolar disorder (BD) is characterized by extreme mood swings ranging from manic/hypomanic to depressive episodes. The severity, duration, and frequency of these episodes can vary widely between individuals, significantly impacting quality of life. Individuals with BD spend almost half their lives experiencing mood symptoms, especially depression, as well as associated clinical dimensions such as anhedonia, fatigue, suicidality, anxiety, and neurovegetative symptoms. Persistent mood symptoms have been associated with premature mortality, accelerated aging, and elevated prevalence of treatment-resistant depression. Recent efforts have expanded our understanding of the neurobiology of BD and the downstream targets that may help track clinical outcomes and drug development. However, as a polygenic disorder, the neurobiology of BD is complex and involves biological changes in several organelles and downstream targets (pre-, post-, and extra-synaptic), including mitochondrial dysfunction, oxidative stress, altered monoaminergic and glutamatergic systems, lower neurotrophic factor levels, and changes in immune-inflammatory systems. The field has thus moved toward identifying more precise neurobiological targets that, in turn, may help develop personalized approaches and more reliable biomarkers for treatment prediction. Diverse pharmacological and non-pharmacological approaches targeting neurobiological pathways other than neurotransmission have also been tested in mood disorders. This article reviews different neurobiological targets and pathophysiological findings in non-canonical pathways in BD that may offer opportunities to support drug development and identify new, clinically relevant biological mechanisms. These include: neuroinflammation; mitochondrial function; calcium channels; oxidative stress; the glycogen synthase kinase-3 (GSK3) pathway; protein kinase C (PKC); brain-derived neurotrophic factor (BDNF); histone deacetylase (HDAC); and the purinergic signaling pathway.

Metabolic regulation to treat bipolar depression: mechanisms and targeting by trimetazidine

Bipolar disorder's core feature is the pathological disturbances in mood, often accompanied by disrupted thinking and behavior. Its complex and heterogeneous etiology implies that a range of inherited and environmental factors are involved. This heterogeneity and poorly understood neurobiology pose significant challenges to existing drug development paradigms, resulting in scarce treatment options, especially for bipolar depression. Therefore, novel approaches are needed to discover new treatment options. In this review, we first highlight the main molecular mechanisms known to be associated with bipolar depression-mitochondrial dysfunction, inflammation and oxidative stress. We then examine the available literature for the effects of trimetazidine in said alterations. Trimetazidine was identified without a priori hypothesis using a gene-expression signature for the effects of a combination of drugs used to treat bipolar disorder and screening a library of off-patent drugs in cultured human neuronal-like cells. Trimetazidine is used to treat angina pectoris for its cytoprotective and metabolic effects (improved glucose utilization for energy production). The preclinical and clinical literature strongly support trimetazidine's potential to treat bipolar depression, having anti-inflammatory and antioxidant properties while normalizing mitochondrial function only when it is compromised. Further, trimetazidine's demonstrated safety and tolerability provide a strong rationale for clinical trials to test its efficacy to treat bipolar depression that could fast-track its repurposing to address such an unmet need as bipolar depression.

Nutraceuticals in mood disorders: current knowledge and future directions

PURPOSE OF REVIEW

There is a large evidence base of clinical trials that have investigated the efficacy of a range of nutraceuticals on mood disorders. The aim of the current review is to provide an update regarding the efficacy and safety of nutraceutical agents in mood disorders and to highlight considerations for future research.

RECENT FINDINGS

Nutraceuticals such as omega-3, probiotics, zinc, saffron and curcumin have been recommended as adjunctive interventions to standard treatments for people with depression, while St John's wort has been recommended as a monotherapy. In contrast, less research has been devoted to investigating the effect of nutraceuticals in bipolar disorder, with omega-3 being weakly recommended as an adjunctive to standard treatments. Although the safety profile of most nutraceuticals appears acceptable, more insight into the long-term effects within a range of cohorts is recommended.

SUMMARY

There are a number of nutraceuticals that have clinical trial support for their use as either adjunctive interventions for depression; however, there is mostly limited support for their use in bipolar disorder. Further randomized controlled trials that take into consideration a number of emerging mechanisms, potential nutraceutical combinations and factors that may predict treatment response are required to inform clinical use.

Nutrition and bipolar disorder: a systematic review

INTRODUCTION

Individuals with bipolar disorder (BD) have higher rates of unhealthy lifestyles and risk for medical comorbidities Research currently suggests that dietary factors may play a role in the development of depression and anxiety. Therefore, nutritional approaches are potential strategies for the treatment of BD. The aim of this review is to summarize the available evidence on nutrition and BD.

MATERIALS AND METHODS

The paper was developed based on PRISMA 2020 guidelines. The search was conducted in Sep-2021 using PubMed and Cochrane Library, augmented by manually checked references lists. The search found 986 studies, of which 47 were included, combined with 13 from reference lists, totaling 60 studies.

RESULTS

There were 33 observational trials, of which 15 focused on fatty acids, 9 on micronutrients, 5 on specific foods, 4 on macro and micronutrients. The 27 interventional studies mainly focused on fatty acids, micronutrients and N-acetylcysteine (NAC).

DISCUSSION

Dietary intake or supplementation of unsaturated fatty acids, mainly Omega-3 seems to be associated with improved BD symptoms, along with seafood, folic acid and zinc. Studies found variable, mainly non-significant impacts of creatine, carnitine, vitamin D, inositol or NAC supplementation on BD. There are promising results associated with Coenzyme Q10 (Coq10) and probiotics. Taken together, these preliminary findings suggest that dietetic approaches might be included as part of BD treatment. Also considering the high risk of metabolic disorders in individuals with BD, they should be encouraged to choose healthy dietary lifestyles, including daily intake of fruits, vegetables, seafood and whole grains.

Effects of Creatine Supplementation on Brain Function and Health

While the vast majority of research involving creatine supplementation has focused on skeletal muscle, there is a small body of accumulating research that has focused on creatine and the brain. Preliminary studies indicate that creatine supplementation (and guanidinoacetic acid; GAA) has the ability to increase brain creatine content in humans. Furthermore, creatine has shown some promise for attenuating symptoms of concussion, mild traumatic brain injury and depression but its effect on neurodegenerative diseases appears to be lacking. The purpose of this narrative review is to summarize the current body of research pertaining to creatine supplementation on total creatine and phophorylcreatine (PCr) content, explore GAA as an alternative or adjunct to creatine supplementation on brain creatine uptake, assess the impact of creatine on cognition with a focus on sleep deprivation, discuss the effects of creatine supplementation on a variety of neurological and mental health conditions, and outline recent advances on creatine supplementation as a neuroprotective supplement following traumatic brain injury or concussion.

Role of Creatine Supplementation in Conditions Involving Mitochondrial Dysfunction: A Narrative Review

Creatine monohydrate (CrM) is one of the most widely used nutritional supplements among active individuals and athletes to improve high-intensity exercise performance and training adaptations. However, research suggests that CrM supplementation may also serve as a therapeutic tool in the management of some chronic and traumatic diseases. Creatine supplementation has been reported to improve high-energy phosphate availability as well as have antioxidative, neuroprotective, anti-lactatic, and calcium-homoeostatic effects. These characteristics may have a direct impact on mitochondrion's survival and health particularly during stressful conditions such as ischemia and injury. This narrative review discusses current scientific evidence for use or supplemental CrM as a therapeutic agent during conditions associated with mitochondrial dysfunction. Based on this analysis, it appears that CrM supplementation may have a role in improving cellular bioenergetics in several mitochondrial dysfunction-related diseases, ischemic conditions, and injury pathology and thereby could provide therapeutic benefit in the management of these conditions. However, larger clinical trials are needed to explore these potential therapeutic applications before definitive conclusions can be drawn.

Mitochondrial modulators in the treatment of bipolar depression: a systematic review and meta-analysis

Mitochondrial dysfunction has been implicated in the risk, pathophysiology, and progression of mood disorders, especially bipolar disorder (BD). Thus, the objective of this meta-analysis was to determine the overall antidepressant effect of mitochondrial modulators in the treatment of bipolar depression. Outcomes included improvement in depression scale scores, Young Mania Rating Scale (YMRS) and Clinical Global Impression-Severity Scale (CGI-S) score. Data from randomized controlled trials (RCTs) assessing the antidepressant effect of diverse mitochondrial modulators were pooled to determine standard mean differences (SMDs) compared with placebo.13 RCTs were identified for qualitative review. The overall effect size of mitochondrial modulators on depressive symptoms was -0.48 (95% CI: -0.83 to -0.14, p = 0.007, I² = 75%), indicative of a statistically significant moderate antidepressant effect. In the subgroup analysis, NAC improved depressive symptoms compared with placebo (-0.88, 95% CI: -1.48 to -0.27, I² = 81%). In addition, there was no statistical difference between mitochondrial modulators and placebo in YMRS. Although mitochondrial modulators were superior to placebo in CGI-S score (-0.44, 95% CI: -0.83 to -0.06, I² = 71%), only EPA was superior to placebo in subgroup analysis. Overall, a moderate antidepressant effect was observed for mitochondrial modulators compared with placebo in the treatment of bipolar depression. The small number of studies, diversity of agents, and small sample sizes limited interpretation of the current analysis.

Comparative efficacy of mitochondrial agents for bipolar disorder during depressive episodes: a network meta-analysis using frequentist and Bayesian approaches

RATIONALE

Mitochondrial dysfunctions have emerged as new biological hypothesis and therapeutic target for bipolar disorder. This network meta-analysis has been done to evaluate the comparative efficacy of mitochondrial agents in bipolar depression.

METHODS

After a comprehensive literature search on PubMed/MEDLINE, Cochrane databases, and International Trials Registry Platform, efficacy data were extracted from 15 randomized controlled trials. Random-effects meta-analysis was done following both frequentist and Bayesian approaches to pool the effects across the interventions. A network graph was built, relative effects of interventions in respect to one another and placebo were calculated, and treatments were ranked as per P- and SUCRA scores. Change in depression rating score was the primary outcome. Data was entered in contrast level and arm level for frequentist and Bayesian approaches, respectively.

RESULTS

Amongst mitochondrial agents, N-acetylcysteine (NAC) was shown to have the highest probability of being the best treatment, followed by coenzyme Q10 and combination therapy of alpha-lipoic acid (ALA) and acetyl-L-carnitine (ALCAR) as depicted by P- and SUCRA scores. In the Bayesian approach, none of the treatments had better efficacy than placebo, but in the frequentist approach, NAC (effect estimate: - 1.18 (95% CI: - 2.05; - 0.31)) was significantly better than placebo.

CONCLUSION

Methodically, there may be a difference of magnitude in frequentist and Bayesian approaches, but the direction of effect and ranking probabilities do not differ. We conclude that none of the existing mitochondrial agents showed better efficacy than placebo in bipolar depression regarding depression rating scores.

Altered brain creatine cycle metabolites in bipolar I disorder with childhood abuse: A 1H magnetic resonance spectroscopy study

BACKGROUND

Childhood abuse (CA) is a risk factor for a number of psychiatric disorders and has been associated with higher risk of developing bipolar disorders (BD). CA in BD has been associated with more severe clinical outcomes, but the neurobiological explanation for this is unknown. Few studies have explored in vivo measurement of brain metabolites using proton magnetic resonance spectroscopy (¹H-MRS) in CA and no studies have investigated the association of CA severity with brain neurometabolites in BD.

OBJECTIVE

To investigate whether CA severity is associated with changes in anterior cingulate cortex (ACC) neurometabolite profile in BD and HC subjects.

METHODS

Fifty-nine BD I euthymic patients and fifty-nine HC subjects were assessed using the Childhood Trauma Questionnaire (CTQ) and underwent a 3-Tesla ¹H-MRS scan. Severity of childhood abuse (physical, sexual and emotional) and its association with levels of brain metabolites was analyzed within each group.

RESULTS

BD patients had higher total scores on the CTQ and higher severity rates of sexual and physical abuse compared to HC subjects. Greater severity of physical and sexual abuse was associated with increased ACC PCr level and lower Cr/PCr ratio in the BD group only.

CONCLUSION

Sexual and physical abuse in BD patients, but not in HC subjects, appeared to be associated with creatine metabolism in the ACC, which can influence neuronal mitochondrial energy production. Further studies should investigate whether this is the mechanism underlying the association between CA and worse clinical outcomes in BD.

The Management of Prodromal Symptoms of Bipolar Disorder: Available Options and Future Perspectives

The onset of prodromal symptoms in subjects who are at familial or clinical risk for bipolar disorder could be considered as an important alarm bell for the development of the disease and should be carefully detected. The management of prodromes in bipolar high-risk patients appears to be an important means of prevention; nevertheless, at the moment, there aren’t clear and widely shared treatment indications. The aim of this review is to summarize the available treatment options (pharmacological, psychosocial and nutraceutical) for the management of prodromal symptoms in subjects who are at familial or clinical risk for bipolar disorder.

Advances in the psychopharmacotherapy of bipolar disorder type I

INTRODUCTION

Research into the pharmacologic management of bipolar type I illness continues to progress.

AREAS COVERED

Randomized clinical trials performed with type I bipolar disorder in the years 2015 to August 2020 are reviewed. There are new indications for the use of cariprazine, for bipolar mania and depression, and a long-acting injectable formulation of aripiprazole has also been approved for relapse prevention in bipolar illness. Most of the randomized clinical trials are effectiveness studies.

EXPERT OPINION

Over the 20 years from 1997 through 2016, the use of lithium and other mood stabilizers has declined by 50%, while the use of both second-generation antipsychotics (SGAs) and antidepressants has increased considerably. Over the same time period (1990-2017), disability-adjusted life years (DALYs) increased by 54.4%, from 6.02 million in 1990 to 9.29 million in 2017 which is greater than the 47.74% increase in incidence of the disease, suggesting that the changes in prescribing patterns have not been helpful for our patients. Furthermore, recent effectiveness studies continue to confirm the superiority of lithium and other mood stabilizers in the management of bipolar illness for both psychiatric and medical outcomes, reaffirming their role as foundational treatments in the management of type I bipolar disorder. Clinicians need to reassess their prescribing habits.

A Systematic Review of Nutraceuticals for the Treatment of Bipolar Disorder

BACKGROUND

Certain nutrient supplements (nutraceuticals) may target neurobiological pathways perturbed in bipolar disorder (BD) such as inflammation, oxidative stress, and mitochondrial dysfunction. Nutraceuticals thus may have a potential role as adjunctive treatments for BD.

METHODS

A search of Embase via embase.com, PubMed via PubMed, Cumulated index to nursing and allied health literature (CINAHL) Complete via EBSCO, and Cochrane Central Register of Controlled Clinical Trials via cochranelibrary.com was conducted to identify published randomized controlled trials assessing the efficacy of nutraceuticals on mood symptomatology in adults with BD. Search terms for BD, nutraceuticals, and clinical trials (total search terms = 75) were used to search from inception to February 20, 2020. The Cochrane Collaboration's tool for assessing the risk of bias in randomized trials was used to assess the risk of bias.

RESULTS

A total of 1,712 studies were identified through the search. After rigorous screening, 22 studies were included in the review. There was large variability across the studies with 15 different nutraceutical agents assessed and as such insufficient homogeneity for a meta-analysis to be conducted (I² > 50%). Studies revealed promising, albeit conflicting, evidence for omega-3 fatty acids and N-acetylcysteine. Isolated positive results were reported for coenzyme Q10.

CONCLUSION

Given nutraceuticals are tolerable and accessible, they may be useful as potential adjunctive treatments for BD. Nutraceuticals targeting neuroinflammation or mitochondrial activity may have the most potential for the depressive phase. However, further studies are required to determine efficacy.

Mitochondrial dysfunction as a critical event in the pathophysiology of bipolar disorder

The understanding of the pathophysiology of bipolar disorder (BD) remains modest, despite recent advances in neurobiological research. The mitochondrial dysfunction hypothesis of bipolar disorder has been corroborated by several studies involving postmortem brain analysis, neuroimaging, and specific biomarkers in both rodent models and humans. Evidence suggests that BD might be related to abnormal mitochondrial morphology and dynamics, neuroimmune dysfunction, and atypical mitochondrial metabolism and oxidative stress pathways. Mitochondrial dysfunction in mood disorders is also associated with abnormal Ca2+ levels, glutamate excitotoxicity, an imbalance between pro- and antiapoptotic proteins towards apoptosis, abnormal gene expression of electron transport chain complexes, and decreased ATP synthesis. This paper aims to review and discuss the implications of mitochondrial dysfunction in BD etiology and to explore mitochondria as a potential target for novel therapeutic agents.

Creatine Supplementation in Children and Adolescents

Creatine is a popular ergogenic aid among athletic populations with consistent evidence indicating that creatine supplementation also continues to be commonly used among adolescent populations. In addition, the evidence base supporting the therapeutic benefits of creatine supplementation for a plethora of clinical applications in both adults and children continues to grow. Among pediatric populations, a strong rationale exists for creatine to afford therapeutic benefits pertaining to multiple neuromuscular and metabolic disorders, with preliminary evidence for other subsets of clinical populations as well. Despite the strong evidence supporting the efficacy and safety of creatine supplementation among adult populations, less is known as to whether similar physiological benefits extend to children and adolescent populations, and in particular those adolescent populations who are regularly participating in high-intensity exercise training. While limited in scope, studies involving creatine supplementation and exercise performance in adolescent athletes generally report improvements in several ergogenic outcomes with limited evidence of ergolytic properties and consistent reports indicating no adverse events associated with supplementation. The purpose of this article is to summarize the rationale, prevalence of use, performance benefits, clinical applications, and safety of creatine use in children and adolescents.

Creatine in Health and Disease

Although creatine has been mostly studied as an ergogenic aid for exercise, training, and sport, several health and potential therapeutic benefits have been reported. This is because creatine plays a critical role in cellular metabolism, particularly during metabolically stressed states, and limitations in the ability to transport and/or store creatine can impair metabolism. Moreover, increasing availability of creatine in tissue may enhance cellular metabolism and thereby lessen the severity of injury and/or disease conditions, particularly when oxygen availability is compromised. This systematic review assesses the peer-reviewed scientific and medical evidence related to creatine's role in promoting general health as we age and how creatine supplementation has been used as a nutritional strategy to help individuals recover from injury and/or manage chronic disease. Additionally, it provides reasonable conclusions about the role of creatine on health and disease based on current scientific evidence. Based on this analysis, it can be concluded that creatine supplementation has several health and therapeutic benefits throughout the lifespan.

New Pharmacological Interventions in Bipolar Disorder

The biological bases of bipolar disorder include aspects related, among others, to neurohormonal pathways, neurotransmission, signal transduction, regulation of gene expression, oxidative stress, neuroplasticity, and changes in the immune system. There is still a gap in understanding its complex neurobiology and, consequently, developing new treatments. Multiple factors probably interact in this complex equation of pathophysiology of bipolar disorder, such as genetic, biochemical, psychosocial, and environmental stress events, correlating with the development and severity of the bipolar disorder. These mechanisms can interact to exacerbate inflammation, impair neurogenesis, and increase oxidative stress damage, cellular mitochondrial dysfunction, changes in neurotrophins and in epigenetic mechanisms, neuroendocrine dysfunction, activation of neuronal death pathways, and dysfunction in neurotransmission systems. In this review, we explore the up-to-date knowledge of the neurobiological underpinnings of bipolar disorders. The difficulty in developing new drugs for bipolar disorder is very much associated with the lack of knowledge about the precise pathophysiology of this disorder. Pharmacological treatment for bipolar patients is vital; to progress to effective medications, it is essential to understand the neurobiology in bipolar patients better and identify novel therapeutic targets.

What is bipolar disorder? A disease model of dysregulated energy expenditure

Advances in the understanding and management of bipolar disorder (BD) have been slow to emerge. Despite notable recent developments in neurosciences, our conceptualization of the nature of this mental disorder has not meaningfully progressed. One of the key reasons for this scenario is the continuing lack of a comprehensive disease model. Within the increasing complexity of modern research methods, there is a clear need for an overarching theoretical framework, in which findings are assimilated and predictions are generated. In this review and hypothesis article, we propose such a framework, one in which dysregulated energy expenditure is a primary, sufficient cause for BD. Our proposed model is centered on the disruption of the molecular and cellular network regulating energy production and expenditure, as well its potential secondary adaptations and compensatory mechanisms. We also focus on the putative longitudinal progression of this pathological process, considering its most likely periods for onset, such as critical periods that challenges energy homeostasis (e.g. neurodevelopment, social isolation), and the resulting short and long-term phenotypical manifestations.

Diet and Neurocognition in Mood Disorders - An Overview of the Overlooked

Bipolar disorder and major depression are associated with significant disability, morbidity, and reduced life expectancy. People with mood disorders have shown higher ratios of unhealthy lifestyle choices, including poor diet quality and suboptimal nutrition. Diet and nutrition impact on brain /mental health, but cognitive outcomes have been less researched in psychiatric disorders. Neurocognitive dysfunction is a major driver of social dysfunction and a therapeutic target in mood disorders, although effective cognitive-enhancers are currently lacking. This narrative review aimed to assess the potential cognitive benefits of dietary and nutritional interventions in subjects diagnosed with mood disorders. Eight clinical trials with nutrients were identified, whereas none involved dietary interventions. Efficacy to improve select cognitive deficits has been reported, but results are either preliminary or inconsistent. Methodological recommendations for future cognition trials in the field are advanced. Current evidence and future views are discussed from the perspectives of precision medicine, clinical staging, nutritional psychiatry, and the brain-gut-microbiota axis.

Targeting Mitochondrial Dysfunction for Bipolar Disorder

People with bipolar disorder (BD) all too often have suboptimal long-term outcomes with existing treatment options. They experience relapsing episodes of depression and mania and also have interepisodic mood and anxiety symptoms. We need to have a better understanding of the pathophysiology of BD if we are to make progress in improving these outcomes. This chapter will focus on the critical role of mitochondria in human functioning, oxidative stress, and the biological mechanisms of mitochondria in BD. Additionally, this chapter will present the evidence that, at least for some people, BD is a product of mitochondrial dysregulation. We review the modulators of mitochondria, the connection between current BD medication treatments and mitochondria, and additional medications that have theoretical potential to treat BD.

Acceptability of dietary or nutritional supplementation in pregnancy (ADONS) - Exploring the consumer's perspective on introducing creatine monohydrate as a pregnancy supplement

BACKGROUND

Pre-clinical studies suggest maternal dietary creatine supplementation during pregnancy could protect babies against hypoxic intrapartum events, however creatine has not been used as a supplement in pregnancy. The aim of this study was to explore pregnant women and healthcare professional's general knowledge, behaviours, and attitudes toward nutritional supplements, and their thoughts on introducing creatine as a pregnancy supplement.

METHODS

Pregnant women (n = 42) and partners (n = 23), attending a tertiary care pregnancy service in Melbourne, Australia, participated in focus groups or semi-structured interviews. Health professionals (n = 100), completed a semi-structured online survey. Descriptive data were analyzed using SPSS 25.0 and qualitative data was managed using NVivo 22.0.

RESULTS

Use of branded nutritional supplements in pregnancy was commonplace and acceptable. All primary healthcare respondents discussed supplements with their patients at first consultation. Supplements consumed corresponded closely to those recommended. Women had good general awareness of commonly recommended nutritional supplements, however, were less aware of the rationale for supplement use. This aligned with health professional's perceptions. Women would consider taking creatine if recommended by their health professional. Health professionals would require detailed safety, beneficence, and efficacy information before recommending creatine supplementation. They would also be more likely to recommend a new supplement in higher-risk pregnancies, where benefits may outweigh any perceived side-effects.

CONCLUSION

There is high acceptance of current recommended nutritional supplements in pregnancy. Implementing creatine as a new supplement will require substantive empirical evidence and changes to clinical guidelines. Public awareness and education would also be essential to consumer acceptability of creatine.

Creatine for the Treatment of Depression

Depressed mood, which can occur in the context of major depressive disorder, bipolar disorder, and other conditions, represents a serious threat to public health and wellness. Conventional treatments are not effective for a significant proportion of patients and interventions that are often beneficial for treatment-refractory depression are not widely available. There is, therefore, an immense need to identify novel antidepressant strategies, particularly strategies that target physiological pathways that are distinct from those addressed by conventional treatments. There is growing evidence from human neuroimaging, genetics, epidemiology, and animal studies that disruptions in brain energy production, storage, and utilization are implicated in the development and maintenance of depression. Creatine, a widely available nutritional supplement, has the potential to improve these disruptions in some patients, and early clinical trials indicate that it may have efficacy as an antidepressant agent.

The effect of adjunctive nutraceuticals in bipolar disorder: A systematic review of randomized placebo-controlled trials

BACKGROUND

Nutraceuticals are a group of compounds of growing interest for mental health professionals. Given the implication of certain nutrients in the onset of bipolar disorder, it has been hypothesized that nutraceuticals might be effective in improving symptoms of the condition (i.e. mania or depression). Our systematic review aimed to evaluate the effectiveness of adjunctive nutraceuticals compared to placebo.

METHODS

We searched the following databases from inception to February 2019: Web of Science, CINAHL, Embase, and PsycINFO. We included only original randomized controlled trials written in English, testing the efficacy of nutraceuticals in add-on to standard care, compared to placebo, in patients with bipolar disorder.

RESULTS

After identifying 6584 potentially relevant publications, we finally included 25 studies, among which six used fatty acids, seven micronutrients, seven amino acids. One study tested probiotics, while in four trials a combination of different types of nutraceuticals was used. Even if some compounds have shown promising results (i.e. fatty acids and N-acetyl cysteine for depression, amino acid drinks and folic acid for mania), the majority of nutraceuticals did not cause significant improvements in comparison to placebo.

LIMITATIONS

We could not perform a meta-analysis due to the high heterogeneity of trials, which were also affected by some methodological caveats.

CONCLUSIONS

Evidence regarding the efficacy of adjunctive nutraceuticals in bipolar disorder is inconsistent. Nevertheless, they appear generally free from relevant side effects. Well-designed trials are needed to further explore the potential role of nutraceuticals in different mood episodes.

Beyond sports: Efficacy and safety of creatine supplementation in pathological or paraphysiological conditions of brain and muscle

Creatine is pivotal in energy metabolism of muscle and brain cells, both in physiological and in pathological conditions. Additionally, creatine facilitates the differentiation of muscle and neuronal cells. Evidence of effectiveness of creatine supplementation in improving several clinical conditions is now substantial, and we review it in this paper. In hereditary diseases where its synthesis is impaired, creatine has a disease-modifying capacity, especially when started soon after birth. Strong evidence, including a Cochrane meta-analysis, shows that it improves muscular strength and general well-being in muscular dystrophies. Significant evidence exists also of its effectiveness in secondary prevention of statin myopathy and of treatment-resistant depression in women. Vegetarians and vegans do not consume any dietary creatine and must synthesize all they need, spending most of their methylation capacity. Nevertheless, they have a lower muscular concentration of creatine. Creatine supplementation has proved effective in increasing muscular and neuropsychological performance in vegetarians or vegans and should, therefore, be recommended especially in those of them who are athletes, heavy-duty laborers or who undergo intense mental effort. Convincing evidence also exists of creatine effectiveness in muscular atrophy and sarcopenia in the elderly, and in brain energy shortage (mental fatigue, sleep deprivation, environmental hypoxia as in mountain climbing, and advanced age). Furthermore, we review more randomized, placebo-controlled trials showing that creatine supplementation is safe up to 20 g/d, with a possible caveat only in people with kidney disease. We trust that the evidence we review will be translated into clinical practice and will spur more research on these subjects.