Creatine target engagement with brain bioenergetics: a dose-ranging phosphorus-31 magnetic resonance spectroscopy study of adolescent females with SSRI-resistant depression

20(S)-Protopanaxadiol Exerts Antidepressive Effects in Chronic Corticosterone-Induced Rodent Animal Models as an Activator of Brain-Type Creatine Kinase

20(S)-Protopanaxadiol (PPD) is one of the bioactive ingredients in ginseng and possesses neuroprotective properties. Brain-type creatine kinase (CK-BB) is an enzyme involved in brain energy homeostasis via the phosphocreatine-creatine kinase system. We previously identified PPD as directly bound to CK-BB and activated its activity in vitro. In this study, we explored the antidepressive effects of PPD that target CK-BB. First, we conducted time course studies on brain CK-BB, behaviors, and hippocampal structural plasticity responses to corticosterone (CORT) administration. Five weeks of CORT injection reduced CK-BB activity and protein levels and induced depression-like behaviors and hippocampal structural plasticity impairment. Next, a CK inhibitor and an adeno-associated virus-targeting CKB were used to diminish CK-BB activity or its expression in the brain. The loss of CK-BB in the brain led to depressive behaviors and morphological damage to spines in the hippocampus. Then, a polyclonal antibody against PPD was used to determine the distribution of PPD in the brain tissues. PPD was detected in the hippocampus and cortex and observed in astrocytes, neurons, and vascular endotheliocytes. Finally, different PPD doses were used in the chronic CORT-induced depression model. Treatment with a high dose of PPD significantly increased the activity and expression of CK-BB after long-term CORT injection. In addition, PPD alleviated the damage to depressive-like behaviors and structural plasticity induced by repeated CORT injection. Overall, our study revealed the critical role of CK-BB in mediating structural plasticity in CORT-induced depression and identified CK-BB as a therapeutic target for PPD, allowing us to treat stress-related mood disorders.

"Heads Up" for Creatine Supplementation and its Potential Applications for Brain Health and Function

There is emerging interest regarding the potential beneficial effects of creatine supplementation on indices of brain health and function. Creatine supplementation can increase brain creatine stores, which may help explain some of the positive effects on measures of cognition and memory, especially in aging adults or during times of metabolic stress (i.e., sleep deprivation). Furthermore, creatine has shown promise for improving health outcome measures associated with muscular dystrophy, traumatic brain injury (including concussions in children), depression, and anxiety. However, whether any sex- or age-related differences exist in regard to creatine and indices of brain health and function is relatively unknown. The purpose of this narrative review is to: (1) provide an up-to-date summary and discussion of the current body of research focusing on creatine and indices of brain health and function and (2) discuss possible sex- and age-related differences in response to creatine supplementation on brain bioenergetics, measures of brain health and function, and neurological diseases.

Creatine as a Therapeutic Target in Alzheimer's Disease

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease, affecting approximately 6.5 million older adults in the United States. Development of AD treatment has primarily centered on developing pharmaceuticals that target amyloid-β (Aβ) plaques in the brain, a hallmark pathological biomarker that precedes symptomatic AD. Though recent clinical trials of novel drugs that target Aβ have demonstrated promising preliminary data, these pharmaceuticals have a poor history of developing into AD treatments, leading to hypotheses that other therapeutic targets may be more suitable for AD prevention and treatment. Impaired brain energy metabolism is another pathological hallmark that precedes the onset of AD that may provide a target for intervention. The brain creatine (Cr) system plays a crucial role in maintaining bioenergetic flux and is disrupted in AD. Recent studies using AD mouse models have shown that supplementing with Cr improves brain bioenergetics, as well as AD biomarkers and cognition. Despite these promising findings, no human trials have investigated the potential benefits of Cr supplementation in AD. This narrative review discusses the link between Cr and AD and the potential for Cr supplementation as a treatment for AD.

The Brain at High Altitude: From Molecular Signaling to Cognitive Performance

The brain requires over one-fifth of the total body oxygen demand for normal functioning. At high altitude (HA), the lower atmospheric oxygen pressure inevitably challenges the brain, affecting voluntary spatial attention, cognitive processing, and attention speed after short-term, long-term, or lifespan exposure. Molecular responses to HA are controlled mainly by hypoxia-inducible factors. This review aims to summarize the cellular, metabolic, and functional alterations in the brain at HA with a focus on the role of hypoxia-inducible factors in controlling the hypoxic ventilatory response, neuronal survival, metabolism, neurogenesis, synaptogenesis, and plasticity.

Functional MRI markers for treatment-resistant depression: Insights and challenges

Imaging studies of treatment-resistant depression (TRD) have examined brain activity, structure, and metabolite concentrations to identify critical areas of investigation in TRD as well as potential targets for treatment interventions. This chapter provides an overview of the main findings of studies using three imaging modalities: structural magnetic resonance imaging (MRI), functional MRI (fMRI), and magnetic resonance spectroscopy (MRS). Decreased connectivity and metabolite concentrations in frontal brain areas appear to characterize TRD, although results are not consistent across studies. Treatment interventions, including rapid-acting antidepressants and transcranial magnetic stimulation (TMS), have shown some efficacy in reversing these changes while alleviating depressive symptoms. However, comparatively few TRD imaging studies have been conducted, and these studies often have relatively small sample sizes or employ different methods to examine a variety of brain areas, making it difficult to draw firm conclusions from imaging studies about the pathophysiology of TRD. Larger studies with more unified hypotheses, as well as data sharing, could help TRD research and spur better characterization of the illness, providing critical new targets for treatment intervention.

Is altitude a determinant of the health benefits of nature exposure? A systematic review and meta-analysis

Introduction

Nature exposure is a widely accepted option for promoting public health owing to the recent surge of scientific evidence. However, the actual settings to facilitate this initiative is yet to be extensively reviewed. In this systematic review, we have aimed to provide an up-to-date summary of interventional studies investigating the psycho-physiological effects of forests and urban forests, including details on their physical settings, and investigate an effect-modifying role of altitude and summarize data on the magnitude and shape of the association.

Methods

A keyword search using five electronic academic databases (PubMed, Embase, PsycINFO, Web of Science, and Scopus) was conducted to identify relevant articles published in English from the inception year to the end of February 2022. The methodological quality was evaluated using the ROBINS-I or ROB2 tool, depending on the study design. Meta-regression and random effects model were jointly used to examine the relationship between altitude and health outcomes.

Results

We included 27 eligible studies and 31 cases extracted from 19 studies were used for the meta-analysis. In the meta-regression, we observed a non-linear association between altitude and psycho-physiological effects. Altitude had a positive quadratic association with anxiety (p < 0.000, adjusted R ² = 96.79%), depression (p < 0.000, adjusted R ² = 98.78%), and fatigue (p < 0.000, adjusted R ² = 64.74%) alleviating effects. Conversely, altitude demonstrated a negative non-linear association with the blood pressure-lowering effect (p = 0.009, adjusted R ² = 32.83%). Additionally, the thermal index (THI) and illuminance (lx) levels were significantly associated with effect sizes of psychological restoration.

Discussion

This review provides moderate-certainty evidence for an effect-modifying role of altitude. The meta-regression results suggested the optimal and minimal altitude ranges for psychological restoration and physiological relaxation, respectively. Despite some limitations, the study findings provide a significant basis for utilizing altitude, which is easily accessible and simple, to promote the health benefits of nature-based initiatives.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022310894, identifier: CRD42022310894.

ROLE OF GUT MICROBIOTA IN DEPRESSION: UNDERSTANDING MOLECULAR PATHWAYS, RECENT RESEARCH, AND FUTURE DIRECTION

Gut microbiota, also known as the "second brain" in humans because of the regulatory role it has on the central nervous system via neuronal, chemical and immune pathways. It has been proven that there exists a bidirectional communication between the gut and the brain. Increasing evidence supports that this crosstalk is linked to the etiology and treatment of depression. Reports suggest that the gut microbiota control the host epigenetic machinery in depression and gut dysbiosis causes negative epigenetic modifications via mechanisms like histone acetylation, DNA methylation and non-coding RNA mediated gene inhibition. The gut microbiome can be a promising approach for the management of depression. The diet and dietary metabolites like kynurenine, tryptophan, and propionic acid also greatly influence the microbiome composition and thereby, the physiological activities. This review gives a bird-eye view on the pathological updates and currently used treatment approaches targeting the gut microbiota in depression.

Low Tissue Creatine: A Therapeutic Target in Clinical Nutrition

Low tissue creatine characterizes many conditions, including neurodegenerative, cardiopulmonary, and metabolic diseases, with a magnitude of creatine shortfall often corresponds well to a disorder’s severity. A non-invasive monitoring of tissue metabolism with magnetic resonance spectroscopy (MRS) might be a feasible tool to evaluate suboptimal levels of creatine for both predictive, diagnostic, and therapeutic purposes. This mini review paper summarizes disorders with deficient creatine levels and provides arguments for assessing and employing tissue creatine as a relevant target in clinical nutrition.

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.

Anxiety, depression, and somatic symptom disorders in health care workers at high altitude during the rapid spread of the SARS-CoV-2 Omicron variant: A prospective cohort study

OBJECTIVE

The ongoing spread of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Omicron variant and hypoxia exposure to high altitude are the susceptible factors of people's psychological abnormalities, especially the health care workers (HCWs) in the front line of the epidemic. There is no dynamic observation data on the prevalence of mental health disorders among HCWs at high altitude. The study is to assess the prevalence of mental health outcomes and its influencing factors among HCWs at high altitude exposed to the SARS-CoV-2 Omicron variant.

METHODS

This prospective cohort study collected sociodemographic data and mental health measurements from 647 HCWs in 3 hospitals in Xining, Qinghai province from 13 April to 4 May 2022. After the mental health intervention for the above-mentioned people in the Chengdong district, we collected mental health indicators on days 7 and 14, respectively. We used the generalized linear model and the generalized estimation equation and for further analysis.

RESULTS

The baseline cross-sectional survey of 647 HCWs in the Chengdong and Chengbei districts of Xining, Qinghai province shows that the prevalence of depression, anxiety, and somatic disorders were 45.75, 46.52, and 52.55%, respectively. The multivariable model showed that chronic diseases and nucleic acid collection were associated with increased scores of GAD-7, PHQ-9, and PHQ-15. And the GAD-7 score of HCWs with elderly people at home increased by 0.92 points. Subsequent repeated measurements of the mental health of HCWs in Chengdong district in Xining, Qinghai province, showed that anxiety, depression, and somatic disorders were significantly relieved, and physical exercise showed a significant protective effect, while loans and nucleic acid collection showed an adverse effect after 2 weeks of intervention. Additionally, engaged in nucleic acid collection was the risk factor of anxiety and depression.

CONCLUSION

In this survey of HCWs on frontline at high altitude during the rapid spread of the SARS-CoV-2 Omicron variant, participants reported experiencing mental health disorders, especially in those with chronic disease, loans, and those who worked with longer hours and engaged in nucleic acid collection in Xining, Qinghai province, China. Exercise may help to improve anxiety and physical disorders.

Relationship between depression, prefrontal creatine and grey matter volume

BACKGROUND

Depression and low mood are leading contributors to disability worldwide. Research indicates that clinical depression may be associated with low creatine concentrations in the brain and low prefrontal grey matter volume. Because subclinical depression also contributes to difficulties in day-to-day life, understanding the neural mechanisms of depressive symptoms in all individuals, even at a subclinical level, may aid public health.

METHODS

Eighty-four young adult participants completed the Depression, Anxiety and Stress Scale (DASS) to quantify severity of depression, anxiety and stress, and underwent 1H-Magnetic Resonance Spectroscopy of the medial prefrontal cortex and structural magnetic resonance imaging (MRI) to determine whole-brain grey matter volume.

RESULTS/OUTCOMES

DASS depression scores were negatively associated (a) with concentrations of creatine (but not other metabolites) in the prefrontal cortex and (b) with grey matter volume in the right superior medial frontal gyrus. Medial prefrontal creatine concentrations and right superior medial frontal grey matter volume were positively correlated. DASS anxiety and DASS stress scores were not related to prefrontal metabolite concentrations or whole-brain grey matter volume.

CONCLUSIONS/INTERPRETATIONS

This study provides preliminary evidence from a representative group of individuals who exhibit a range of depression levels that prefrontal creatine and grey matter volume are negatively associated with depression. While future research is needed to fully understand this relationship, these results provide support for previous findings, which indicate that increasing creatine concentrations in the prefrontal cortex may improve mood and well-being.

Inhibitory and excitatory neurotransmitter systems in depressed and healthy: A positron emission tomography and magnetic resonance spectroscopy study

The Gamma-aminobutyric acid (GABA) and glutamate (Glu) neurotransmitter systems are implicated in depression. While previous studies found reduced GABA levels, and a tendency towards reduced Glu, using proton (¹H) magnetic resonance spectroscopy (¹H-MRS), little is known about GABA_A receptor availability in depression. Here, the aim was to characterize GABA and Glu-levels in dorsal anterior cingulate cortex (dACC), whole-brain GABA_A availability, and their relationship in patients with depression compared to healthy controls. Forty-two patients and 45 controls underwent ¹H-MRS using a MEGA-PRESS sequence to quantify dACC GABA+ and Glu (contrasted against creatine [Cr]). Immediately preceding the ¹H-MRS, a subsample of 28 patients and 15 controls underwent positron emission tomography (PET) with [¹¹C]Flumazenil to assess whole-brain GABA_A receptor availability. There were no differences in dACC GABA+/Cr or Glu/Cr ratios between patients and controls. The same was true for whole-brain GABA_A receptor availability. However, there was a significant negative relationship between GABA+/Cr ratio and receptor availability in ACC, in a whole-brain voxel-wise analysis across patients and controls, controlling for group or depressive symptoms. This relatively large study did not support the GABA-deficit hypothesis in depression, but shed light on GABA-system functioning, suggesting a balance between neurotransmitter concentration and receptor availability in dACC.

Sex-Based Impact of Creatine Supplementation on Depressive Symptoms, Brain Serotonin and SSRI Efficacy in an Animal Model of Treatment-Resistant Depression

Background: Rates of major depressive disorder (MDD) increase with living at altitude. In our model, rats housed at moderate altitude (in hypobaric hypoxia) exhibit increased depression-like behavior, altered brain serotonin and a lack of antidepressant response to most selective serotonin reuptake inhibitors (SSRIs). A forebrain deficit in the bioenergetic marker creatine is noted in people living at altitude or with MDD. Methods: Rats housed at 4500 ft were given dietary creatine monohydrate (CRMH, 4% w/w, 5 weeks) vs. un-supplemented diet, and impact on depression-like behavior, brain bioenergetics, serotonin and SSRI efficacy assessed. Results: CRMH significantly improved brain creatine in a sex-based manner. At altitude, CRMH increased serotonin levels in the female prefrontal cortex and striatum but reduced male striatal and hippocampal serotonin. Dietary CRMH was antidepressant in the forced swim test and anti-anhedonic in the sucrose preference test in only females at altitude, with motor behavior unchanged. CRMH improved fluoxetine efficacy (20 mg/kg) in only males at altitude: CRMH + SSRI significantly improved male striatal creatine and serotonin vs. CRMH alone. Conclusions: Dietary CRMH exhibits sex-based efficacy in resolving altitude-related deficits in brain biomarkers, depression-like behavior and SSRI efficacy, and may be effective clinically for SSRI-resistant depression at altitude. This is the first study to link CRMH treatment to improving brain serotonin.

Creatine Supplementation for Patients with Inflammatory Bowel Diseases: A Scientific Rationale for a Clinical Trial

Based on theoretical considerations, experimental data with cells in vitro, animal studies in vivo, as well as a single case pilot study with one colitis patient, a consolidated hypothesis can be put forward, stating that “oral supplementation with creatine monohydrate (Cr), a pleiotropic cellular energy precursor, is likely to be effective in inducing a favorable response and/or remission in patients with inflammatory bowel diseases (IBD), like ulcerative colitis and/or Crohn’s disease”. A current pilot clinical trial that incorporates the use of oral Cr at a dose of 2 × 7 g per day, over an initial period of 2 months in conjunction with ongoing therapies (NCT02463305) will be informative for the proposed larger, more long-term Cr supplementation study of 2 × 3–5 g of Cr per day for a time of 3–6 months. This strategy should be insightful to the potential for Cr in reducing or alleviating the symptoms of IBD. Supplementation with chemically pure Cr, a natural nutritional supplement, is well tolerated not only by healthy subjects, but also by patients with diverse neuromuscular diseases. If the outcome of such a clinical pilot study with Cr as monotherapy or in conjunction with metformin were positive, oral Cr supplementation could then be used in the future as potentially useful adjuvant therapeutic intervention for patients with IBD, preferably together with standard medication used for treating patients with chronic ulcerative colitis and/or Crohn’s disease.

Creatine Supplementation in Women's Health: A Lifespan Perspective

Despite extensive research on creatine, evidence for use among females is understudied. Creatine characteristics vary between males and females, with females exhibiting 70–80% lower endogenous creatine stores compared to males. Understanding creatine metabolism pre- and post-menopause yields important implications for creatine supplementation for performance and health among females. Due to the hormone-related changes to creatine kinetics and phosphocreatine resynthesis, supplementation may be particularly important during menses, pregnancy, post-partum, during and post-menopause. Creatine supplementation among pre-menopausal females appears to be effective for improving strength and exercise performance. Post-menopausal females may also experience benefits in skeletal muscle size and function when consuming high doses of creatine (0.3 g·kg⁻¹·d⁻¹); and favorable effects on bone when combined with resistance training. Pre-clinical and clinical evidence indicates positive effects from creatine supplementation on mood and cognition, possibly by restoring brain energy levels and homeostasis. Creatine supplementation may be even more effective for females by supporting a pro-energetic environment in the brain. The purpose of this review was to highlight the use of creatine in females across the lifespan with particular emphasis on performance, body composition, mood, and dosing strategies.

Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show?

Supplementing with creatine is very popular amongst athletes and exercising individuals for improving muscle mass, performance and recovery. Accumulating evidence also suggests that creatine supplementation produces a variety of beneficial effects in older and patient populations. Furthermore, evidence-based research shows that creatine supplementation is relatively well tolerated, especially at recommended dosages (i.e. 3-5 g/day or 0.1 g/kg of body mass/day). Although there are over 500 peer-refereed publications involving creatine supplementation, it is somewhat surprising that questions regarding the efficacy and safety of creatine still remain. These include, but are not limited to: 1. Does creatine lead to water retention? 2. Is creatine an anabolic steroid? 3. Does creatine cause kidney damage/renal dysfunction? 4. Does creatine cause hair loss / baldness? 5. Does creatine lead to dehydration and muscle cramping? 6. Is creatine harmful for children and adolescents? 7. Does creatine increase fat mass? 8. Is a creatine 'loading-phase' required? 9. Is creatine beneficial for older adults? 10. Is creatine only useful for resistance / power type activities? 11. Is creatine only effective for males? 12. Are other forms of creatine similar or superior to monohydrate and is creatine stable in solutions/beverages? To answer these questions, an internationally renowned team of research experts was formed to perform an evidence-based scientific evaluation of the literature regarding creatine supplementation.

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.

Plasma Neuronal and Glial Markers and Anterior Cingulate Metabolite Levels in Major Depressive Disorder: A Pilot Study

INTRODUCTION

Neuroglial functions may be deteriorated in major depressive disorder (MDD).

OBJECTIVE

To evaluate the markers of glial and neuronal cell turnover and to explore their associations with brain metabolites.

METHODS

In 10 participants with MDD and 10 healthy controls (HC) we investigated neuronal and glial plasma markers (the neuron-specific enolase, NSE; and S100beta, S100B) and brain metabolites (N-acetyl aspartate, NAA; total choline, Cho; and total creatine, Cr). Blood was collected for NSE and S100B. NAA, Cho, and Cr metabolite levels were measured in the anterior cingulate cortex (ACC) with proton magnetic resonance spectroscopy (1H-MRS) at 3T.

RESULTS

NSE and S100B levels were significantly higher in MDD subjects than in HC. The Cr level was significantly higher in MDD subjects than in HC, but the NAA and Cho levels did not differ between groups. NAA/Cr and Cho/Cr ratios were significantly lower in patients with MDD versus HC. S100B was negatively correlated with the Cho levels.

CONCLUSIONS

These results provide supporting evidence of neuronal and glial distress in MDD. Neuronal viability appears decreased, whereas glial regenerative activity and energy metabolism in the ACC increase in acute major depressive episode. Since low concentrations of S100B have neuroplastic effects, these changes may indicate a possible compensatory mechanism.

Differential and spatial expression meta-analysis of genes identified in genome-wide association studies of depression

Major depressive disorder (MDD) is the most prevalent psychiatric disorder worldwide and affects individuals of all ages. It causes significant psychosocial impairments and is a major cause of disability. A recent consortium study identified 102 genetic variants and 269 genes associated with depression. To provide targets for future depression research, we prioritized these recently identified genes using expression data. We examined the differential expression of these genes in three studies that profiled gene expression of MDD cases and controls across multiple brain regions. In addition, we integrated anatomical expression information to determine which brain regions and transcriptomic cell types highly express the candidate genes. We highlight 12 of the 269 genes with the most consistent differential expression: MANEA, UBE2M, CKB, ITPR3, SPRY2, SAMD5, TMEM106B, ZC3H7B, LST1, ASXL3, ZNF184 and HSPA1A. The majority of these top genes were found to have sex-specific differential expression. We place greater emphasis on ZNF184 as it is the top gene in a more conservative analysis of the 269. Specifically, the differential expression of ZNF184 was strongest in subcortical regions in males and females. Anatomically, our results suggest the importance of the dorsal lateral geniculate nucleus, cholinergic, monoaminergic and enteric neurons. These findings provide a guide for targeted experiments to advance our understanding of the genetic underpinnings of depression.

The neurobiology of wellness: 1H-MRS correlates of agency, flexibility and neuroaffective reserves in healthy young adults

Proton magnetic resonance spectroscopy (¹H-MRS) is a noninvasive imaging technique that measures the concentration of metabolites in defined areas of the human brain in vivo. The underlying structure of natural metabolism-emotion relationships is unknown. Further, there is a wide range of between-person differences in metabolite concentration in healthy individuals, but the significance of this variation for understanding emotion in healthy humans is unclear. Here we investigated the relationship of two emotional constructs, agency and flexibility, with the metabolites glutamate and glutamine (Glx), N-acetylaspartate (tNAA), choline (Cho), creatine (tCr), and myo-inositol (Ins) in the right dorsal anterior cingulate cortex (dACC) in medically and psychiatrically healthy volunteers (N = 20, 9 female; mean age = 22.8 years, SD = 3.40). The dACC was selected because this region is an integrative hub involved in multiple brain networks of emotion, cognition and behavior. Emotional traits were assessed using the Multidimensional Personality Questionnaire Brief Form (MPQ-BF), an empirically derived self-report instrument with an orthogonal factor structure. Phenotypes evaluated were positive and negative agency (MPQ-BF Social Potency, Aggression), emotional and behavioral flexibility (MPQ-BF Absorption, Control-reversed), and positive and negative affect (MPQ-BF Social Closeness; Stress Reaction, Alienation). The resting concentration of tNAA in the dACC was robustly positively correlated with Absorption (r = +0.56, unadjusted p = .005), moderately positively correlated with Social Potency (r = +0.42, unadjusted p = .03), and robustly negatively correlated with Aggression (r = −0.59, unadjusted p = .003). Absorption and Aggression accounted for substantial variance in tNAA (R² = 0.31, 0.35; combined R² = 0.50), and survived correction for multiple comparisons (Holm-Bonferroni adjusted p = .032, 0.021, respectively). dACC Glx and Cho had modest relationships with behavioral flexibility and social affiliation that did not survive this multiple correction, providing effect sizes for future work. Principal Component Analysis (PCA) revealed a three-factor orthogonal solution indicating specific relationships between: 1) Glx and behavioral engagement; 2) Cho and affiliative bonding; and 3) tNAA and a novel dimension that we term neuroaffective reserves. Our results inform the neurobiology of agency and flexibility and lay the groundwork for understanding mechanisms of natural emotion using ¹H-MRS.

Altered neurometabolism in major depressive disorder: A whole brain 1H-magnetic resonance spectroscopic imaging study at 3T

INTRODUCTION

Major depressive disorder (MDD) is a severe mental disorder with a neurobiological basis that is poorly understood. Several studies demonstrated widespread, functional and neurometabolic alterations in MDD. However, little is known about whole brain neurometabolic alterations in MDD.

METHOD

Thirty-two patients with MDD and 32 paired on a one-to-one basis healthy controls (CTRL) underwent ¹H-whole brain spectroscopic (¹H-WBS) imaging. Lobar and cerebellar metabolite concentrations of brain N-acetylaspartate (NAA), total choline (tCho), total creatine (tCr), glutamine (Gln), glutamate (Glu), and myo-Inositol (mI) were assessed in patients and controls.

RESULTS

Decreased NAA, tCho, and tCr were found in the right frontal and right parietal lobe in MDD compared to CTRL, and to a lesser extent in the left frontal lobe. Furthermore, in MDD increased glutamine was observed in the right frontal lobe and bitemporal lobes, and increased glutamate in the cerebellum.

CONCLUSION

Altered global neurometabolism examined using ¹H-WBS imaging in MDD may be interpreted as signs of neuronal dysfunction, altered energy metabolism, and oligodendrocyte dysfunction. In particular, the parallel decrease in NAA, tCr and tCho in the same brain regions may be indicative of neuronal dysfunction that may be counterbalanced by an increase of the neuroprotective metabolite glutamine. Future prospective investigations are warranted to study the functional importance of these findings.

Risk of Adverse Outcomes in Females Taking Oral Creatine Monohydrate: A Systematic Review and Meta-Analysis

Creatine Monohydrate (CrM) is a dietary supplement routinely used as an ergogenic aid for sport and training, and as a potential therapeutic aid to augment different disease processes. Despite its increased use in recent years, studies reporting potential adverse outcomes of CrM have been mostly derived from male or mixed sex populations. A systematic search was conducted, which included female participants on CrM, where adverse outcomes were reported, with meta-analysis performed where appropriate. Six hundred and fifty-six studies were identified where creatine supplementation was the primary intervention; fifty-eight were female only studies (9%). Twenty-nine studies monitored for adverse outcomes, with 951 participants. There were no deaths or serious adverse outcomes reported. There were no significant differences in total adverse events, (risk ratio (RR) 1.24 (95% CI 0.51, 2.98)), gastrointestinal events, (RR 1.09 (95% CI 0.53, 2.24)), or weight gain, (mean difference (MD) 1.24 kg pre-intervention, (95% CI -0.34, 2.82)) to 1.37 kg post-intervention (95% CI -0.50, 3.23)), in CrM supplemented females, when stratified by dosing regimen and subject to meta-analysis. No statistically significant difference was reported in measures of renal or hepatic function. In conclusion, mortality and serious adverse events are not associated with CrM supplementation in females. Nor does the use of creatine supplementation increase the risk of total adverse outcomes, weight gain or renal and hepatic complications in females. However, all future studies of creatine supplementation in females should consider surveillance and comprehensive reporting of adverse outcomes to better inform participants and health professionals involved in future trials.

Primary outcome reporting in adolescent depression clinical trials needs standardization

BACKGROUND

Evidence-based health care is informed by results of randomized clinical trials (RCTs) and their syntheses in meta-analyses. When the trial outcomes measured are not clearly described in trial publications, knowledge synthesis, translation, and decision-making may be impeded. While heterogeneity in outcomes measured in adolescent major depressive disorder (MDD) RCTs has been described, the comprehensiveness of outcome reporting is unknown. This study aimed to assess the reporting of primary outcomes in RCTs evaluating treatments for adolescent MDD.

METHODS

RCTs evaluating treatment interventions in adolescents with a diagnosis of MDD published between 2008 and 2017 specifying a single primary outcome were eligible for outcome reporting assessment. Outcome reporting assessment was done independently in duplicate using a comprehensive checklist of 58 reporting items. Primary outcome information provided in each RCT publication was scored as "fully reported", "partially reported", or "not reported" for each checklist item, as applicable.

RESULTS

Eighteen of 42 identified articles were found to have a discernable single primary outcome and were included for outcome reporting assessment. Most trials (72%) did not fully report on over half of the 58 checklist items. Items describing masking of outcome assessors, timing and frequency of outcome assessment, and outcome analyses were fully reported in over 70% of trials. Items less frequently reported included outcome measurement instrument properties (ranging from 6 to 17%), justification of timing and frequency of outcome assessment (6%), and justification of criteria used for clinically significant differences (17%). The overall comprehensiveness of reporting appeared stable over time.

CONCLUSIONS

Heterogeneous reporting exists in published adolescent MDD RCTs, with frequent omissions of key details about their primary outcomes. These omissions may impair interpretability, replicability, and synthesis of RCTs that inform clinical guidelines and decision-making in this field. Consensus on the minimal criteria for outcome reporting in adolescent MDD RCTs is needed.

Dietary creatine intake and depression risk among U.S. adults

Creatine monohydrate is actively being researched for its antidepressant effects, yet little is known about the link between dietary creatine and depression risk. This study examines the association between dietary creatine and depression in U.S. adults, using data from the 2005 to 2012 National Health and Nutrition Examination Survey (NHANES). Patient health questionnaire, dietary creatine intake and covariates were obtained on 22,692 NHANES participants ≥20 years of age. Depression prevalence was calculated within quartiles of dietary creatine intake. Adjusted logistic regression models were formulated to determine the relationship between dietary creatine intake and depression risk. Additional covariates included income to poverty ratio, race/ethnicity, sex, age, education level, body mass index, healthcare access, smoking status, physical activity, and antidepressant/anxiolytic medication use. Models were further stratified by sex, age group, and antidepressant/anxiolytic medication use. Depression prevalence was 10.23/100 persons (95% CI: 8.64-11.83) among NHANES participants in the lowest quartile of dietary creatine intake compared with 5.98/100 persons (95% CI: 4.97-6.98) among participants in the highest quartile (p < 0.001). An inverse association was measured between dietary creatine and depression (adjusted odds ratio (AOR) = 0.68, 95% CI: 0.52-0.88). Dietary creatine's negative association with depression was strongest in females (AOR = 0.62, 95% CI: 0.40-0.98), participants aged 20-39 years (AOR = 0.52, 95% CI: 0.34-0.79) and participants not taking antidepressant/anxiolytic medication (AOR = 0.58, 95% CI: 0.43-0.77). Study results indicate a significant negative relationship between dietary creatine and depression in a nationally representative adult cohort. Further research is warranted to investigate the role creatine plays in depression, particularly among women and across the lifespan.

New Somatic Treatments for Child and Adolescent Depression

PURPOSE OF REVIEW

Depression is a common clinical problem in youth, with prevalence increasing significantly during the adolescent period. Although several evidence-based treatments are currently available for treating depression in adults, only a subset of these have been investigated in a pediatric sample. Unfortunately, even well-established, first-line interventions do not lead to sufficient treatment response for many children and adolescents suffering from depression. However, recent research has been conducted in the area of somatic treatments for youth with depression. This review focuses on current (past three years, including published results and ongoing studies) research on somatic treatments for adolescent depression in the following categories: psychopharmacology, nutraceuticals, interventions implicating motor and sensory systems, and neuromodulation.

FINDINGS

Results from recent randomized, controlled trials testing psychopharmacological options suggest that while antidepressants that have been recently approved for adult patients are safe and tolerable in children and adolescents, none have yet outperformed performed placebo in efficacy. Nutraceuticals, motor-sensory interventions, and neuromodulation techniques, present safe and promising results, but few have been tested against controls to support effectiveness over current treatment options.

SUMMARY

This review of research on pediatric depression treatment from the past 3 years highlights some disappointments (negative results following some of the well-designed clinical trials) and gaps (preliminary studies in need of follow up with robust methodology) but also some promising directions in research of the efficacyof these treatments in a pediatric sample. We offer suggestions for future research including consideration of treatment timing, sequencing, the role of symptom severity in directing treatment selection, the potential value of combined treatments, consideration of how to best account for high placebo response rates, and the incorporation of neurobiological assessments to examine mechanisms and biomarker predictors of treatment response.

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.

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.

The possible beneficial effects of creatine for the management of depression

Depression, a highly prevalent neuropsychiatric disorder worldwide, causes a heavy burden for the society and is associated with suicide risk. The treatment of this disorder remains a challenge, since currently available antidepressants provide a slow and, often, incomplete response and cause several side effects that contribute to diminish the adhesion of patients to treatment. In this context, several nutraceuticals have been investigated regarding their possible beneficial effects for the management of this neuropsychiatric disorder. Creatine stands out as a supplement frequently used for ergogenic purpose, but it also is a neuroprotective compound with potential to treat or mitigate a broad range of central nervous systems diseases, including depression. This review presents preclinical and clinical evidence that creatine may exhibit antidepressant properties. The focus is given on the possible molecular mechanisms underlying its effects based on the results obtained with different animal models of depression. Finally, evidence obtained in animal models of depression addressing the possibility that creatine may produce rapid antidepressant effect, similar to ketamine, are also presented and discussed.

Living High and Feeling Low: Altitude, Suicide, and Depression

After participating in this activity, learners should be better able to:• Assess epidemiologic evidence that increased altitude of residence is linked to increased risk of depression and suicide• Evaluate strategies to address hypoxia-related depression and suicidal ideation ABSTRACT: Suicide and major depressive disorder (MDD) are complex conditions that almost certainly arise from the influences of many interrelated factors. There are significant regional variations in the rates of MDD and suicide in the United States, suggesting that sociodemographic and environmental conditions contribute. Here, we review epidemiological evidence that increases in the altitude of residence are linked to the increased risk of depression and suicide. We consider the possibility that chronic hypobaric hypoxia (low blood oxygen related to low atmospheric pressure) contributes to suicide and depression, which is suggested by animal models, short-term studies in humans, and the effects of hypoxic medical conditions on suicide and depression. We argue that hypobaric hypoxia could promote suicide and depression by altering serotonin metabolism and brain bioenergetics; both of these pathways are implicated in depression, and both are affected by hypoxia. Finally, we briefly examine treatment strategies to address hypoxia-related depression and suicidal ideation that are suggested by these findings, including creatine monohydrate and the serotonin precursors tryptophan and 5-hydroxytryptophan.

The Assertive Brain: Anterior Cingulate Phosphocreatine plus Creatine Levels Correlate With Self-Directedness in Healthy Adolescents

Despite various advances in the study of the neurobiological underpinnings of personality traits, the specific neural correlates associated with character and temperament traits are not yet fully understood. Therefore, this study aims to fill this gap by exploring the biochemical basis of personality, which is explored with the temperament and character inventory (TCI), during brain development in a sample of adolescents. Twenty-six healthy adolescents (aged between 13 and 21 years; 17 males and 9 females) with behavioral and emotional problems underwent a TCI evaluation and a 3T single-voxel proton magnetic resonance spectroscopy (¹H MRS) acquisition of the anterior cingulate cortex (ACC). Absolute metabolite levels were estimated using LCModel: significant correlations between metabolite levels and selective TCI scales were identified. Specifically, phosphocreatine plus creatine (PCr+Cre) significantly correlated with self-directedness, positively, and with a self-transcendence (ST), negatively, while glycerophosphocholine plus phosphocholine (GPC+PC) and myo-inositol negatively correlated with ST. To the best of our knowledge, this is the first study reporting associations of brain metabolites with personality traits in adolescents. Therefore, our results represent a step forward for personality neuroscience within the study of biochemical systems and brain structures.

Altitude and risk of depression and anxiety: findings from the intern health study

Multiple studies suggest that the risks of depression and suicide increase with increasing altitude of residence, but no studies have assessed whether changing altitude changes these risks. To address this gap, this study used data from the Intern Health Study, which follows students from the end of medical school through the first year of residency, recording depression via the 9-item Patient Health Questionnaire (PHQ-9), anxiety via the 7-item Generalized Anxiety Disorder Questionnaire (GAD-7), and multiple risk factors for these symptoms. Data from 3764 medical students representing 46 schools and 282 residencies were available. Odds ratios (OR) representing the effects of altitude on psychiatric symptoms were estimated using generalized linear models. After excluding participants with missing altitude data, 3731 medical students were analyzed. High altitude residence (> 900 m) was significantly associated with PHQ-9 total score (OR = 1.32, 95% CI = 1.001-1.75, p < 0.05), and PHQ-9 suicidal ideation (OR = 1.79, 95% CI = 1.08-0.02, p = 0.02). Moving from low to high altitude was significantly associated with PHQ-9 total score (OR = 1.47, 95% CI = 1.087-1.98, p = 0.01), GAD-7 total score (OR = 1.40, 95% CI = 1.0040-1.95, p < 0.05), and PHQ-9 suicidal ideation (OR = 1.10, 95% CI = 1.01-1.19, p = 0.02). The data suggest that moving from low to high altitude is associated with increasing symptoms of depression, anxiety, and suicidal ideation.

Novel Targets for Fast Antidepressant Responses: Possible Role of Endogenous Neuromodulators

The available medications for the treatment of major depressive disorder have limitations, particularly their limited efficacy, delayed therapeutic effects, and the side effects associated with treatment. These issues highlight the need for better therapeutic agents that provide more efficacious and faster effects for the management of this disorder. Ketamine, an N-methyl-D-aspartate receptor antagonist, is the prototype for novel glutamate-based antidepressants that has been shown to cause a rapid and sustained antidepressant effect even in severe refractory depressive patients. Considering the importance of these findings, several studies have been conducted to elucidate the molecular targets for ketamine's effect. In addition, efforts are under way to characterize ketamine-like drugs. This review focuses particularly on evidence that endogenous glutamatergic neuromodulators may be able to modulate mood and to elicit fast antidepressant responses. Among these molecules, agmatine and creatine stand out as those with more published evidence of similarities with ketamine, but guanosine and ascorbic acid have also provided promising results. The possibility that these neuromodulators and ketamine have common neurobiological mechanisms, mainly the ability to activate mechanistic target of rapamycin and brain-derived neurotrophic factor signaling, and synthesis of synaptic proteins in the prefrontal cortex and/or hippocampus is presented and discussed.

Subchronic administration of creatine produces antidepressant-like effect by modulating hippocampal signaling pathway mediated by FNDC5/BDNF/Akt in mice

Creatine has been shown to play a significant role in the pathophysiology and treatment of major depressive disorder (MDD) in preclinical and clinical studies. However, the biological mechanisms underlying its antidepressant effect is still not fully elucidated. This study investigated the effect of creatine (p.o.) administered for 21 days in the behavior of mice submitted to tail suspension test (TST), a predictive test of antidepressant activity. Creatine reduced the immobility time in the TST (1-10 mg/kg), without affecting locomotor activity, a finding consistent with an antidepressant profile. Creatine administration increased the ubiquitous creatine kinase (uCK) and creatine kinase brain isoform (CK-B) mRNA in the hippocampus of mice. Taking into account that PGC-1α induces FNDC5/irisin expression mediating BDNF-dependent neuroplasticity, the effect of creatine administration (1 mg/kg, p. o.) on the hippocampal PGC-1α, FNDC5 and BDNF gene expression was investigated. Creatine treatment increased PGC-1α, FNDC5 and BDNF mRNA in the hippocampus as well as BDNF immunocontent. The involvement of BDNF downstream intracellular signaling pathway mediated by Akt, proapoptotic proteins BAX and BAD and antiapoptotic proteins Bcl2 and Bcl-xL was also investigated following creatine treatment. Creatine increased Akt phosphorylation (Ser 473), and Bcl2 mRNA and protein levels, and Bcl-xL mRNA, whereas BAD mRNA was decreased following creatine administration in the hippocampus. Altogether these results indicate that creatine antidepressant-like effect may be dependent on Akt activation and increased expression of the neuroprotective proteins in the hippocampus of mice. The obtained data reinforce the antidepressant property of creatine and highlight the role of these molecular targets in the pathophysiology of MDD.

Beyond muscle: the effects of creatine supplementation on brain creatine, cognitive processing, and traumatic brain injury

The ergogenic and therapeutic effects of increasing muscle creatine by supplementation are well-recognized. It appears that similar benefits to brain function and cognitive processing may also be achieved with creatine supplementation, however research in this area is more limited, and important knowledge gaps remain. The purpose of this review is to provide a comprehensive overview of the current state of knowledge about the influence of creatine supplementation on brain function in healthy individuals. It appears that brain creatine is responsive to supplementation, however higher, or more prolonged dosing strategies than those typically used to increase muscle creatine, may be required to elicit an increase in brain creatine. The optimal dosing strategy to induce this response, is currently unknown, and there is an urgent need for studies investigating this. When considering the influence of supplementation strategies on cognitive processes, it appears that creatine is most likely to exert an influence in situations whereby cognitive processes are stressed, e.g. during sleep deprivation, experimental hypoxia, or during the performance of more complex, and thus more cognitively demanding tasks. Evidence exists indicating that increased brain creatine may be effective at reducing the severity of, or enhancing recovery from mild traumatic brain injury, however, only limited data in humans are available to verify this hypothesis, thus representing an exciting area for further research.

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

Depressive episodes are a major cause of morbidity and dysfunction in individuals suffering from bipolar disorder. Currently available treatments for this condition have limited efficacy and new therapeutic options are needed. Extensive research in the pathophysiology of bipolar disorder points to the existence of mitochondrial and bioenergetic dysfunction. We hypothesized that creatine monohydrate, a nutraceutical that works as a mitochondrial modulator, would be effective as an adjunctive therapy for bipolar depression. We conducted a double-blind trial in which 35 patients with bipolar disorder type I or II in a depressive episode by DSM-IV criteria and in use of regular medication for the treatment of this phase of the disease were randomly allocated into two adjunctive treatment groups for 6 weeks: creatine monohydrate 6 g daily (N = 17) or placebo (N = 18). Primary efficacy was assessed by the change in the Montgomery–Åsberg Depression Rating Scale (MADRS). We did not find a statistically significant difference in the comparison between groups for the change in score on the MADRS after 6 weeks in an intention-to-treat (ITT) analysis (p = 0.560; Cohen’s d = 0.231). However, we found significant superiority of creatine add-on vs. placebo when we considered the remission criterion of a MADRS score ≤ 12 at week 6 analyzing the outcome of the 35 randomized patients on ITT (52.9% remission in the creatine group vs. 11.1% remission in the placebo group) and of the 23 completers (66.7% remission in the creatine group vs. 18.2% remission in the placebo group) (p = 0.012; OR = 9.0 and p = 0.036; OR = 9.0, respectively). Two patients who received creatine switched to hypomania/mania early in the trial. No clinically relevant physical side-effects were reported or observed. This proof-of-concept study, aiming to restore brain bioenergetics using an adjunctive mitochondrial modulator, is not conclusive on the efficacy of creatine add-on for bipolar depression, but suggests that this compound may have a role in the adjunctive treatment of this phase of the illness. Further investigation through randomized controlled trials with larger samples should be conducted to verify the efficacy of creatine supplementation for bipolar depression and also for subsyndromal depressive symptoms.

An Open-Label Pilot Study of Combined Augmentation With Creatine Monohydrate and 5-Hydroxytryptophan for Selective Serotonin Reuptake Inhibitor- or Serotonin-Norepinephrine Reuptake Inhibitor-Resistant Depression in Adult Women

PURPOSE

Many women with major depressive disorder (MDD) respond inadequately to standard treatments. Augmentation of conventional antidepressants with creatine monohydrate and 5-hydroxytryptophan (5-HTP) could correct deficits in serotonin production and brain bioenergetics associated with depression in women, yielding synergistic benefit. We describe an open-label study of 5-HTP and creatine augmentation in women with MDD who had failed selective serotonin reuptake inhibitor (SSRI) or serotonin-norepinephrine reuptake inhibitor (SNRI) monotherapy.

METHODS

Fifteen women who were adequately adherent to an SSRI or SNRI and currently experiencing MDD, with a 17-item Hamilton Depression Rating Scale (HAM-D) score of 16 or higher, were treated with 5 g of creatine monohydrate daily and 100 mg of 5-HTP twice daily for 8 weeks, with 4 weeks of posttreatment follow-up. The primary outcome was change in mean HAM-D scores.

RESULTS

Mean HAM-D scores declined from 18.9 (SD, 2.5) at pretreatment visits to 7.5 (SD, 4.4) (P < 0.00001), a decrease of 60%. Participants did not experience any serious treatment-related adverse events.

CONCLUSIONS

Combination treatment with creatine and 5-HTP may represent an effective augmentation strategy for women with SSRI- or SNRI-resistant depression. Given the limitations of this small, open-label trial, future study in randomized, placebo-controlled trials is warranted.

Magnetic Resonance Spectroscopy and its Clinical Applications: A Review

In vivo NMR spectroscopy is known as magnetic resonance spectroscopy (MRS). MRS has been applied as both a research and a clinical tool in order to detect visible or nonvisible abnormalities. The adaptability of MRS allows a technique that can probe a wide variety of metabolic uses across different tissues. Although MRS is mostly applied for brain tissue, it can be used for detection, localization, staging, tumour aggressiveness evaluation, and tumour response assessment of breast, prostate, hepatic, and other cancers. In this article, the medical applications of MRS in the brain, including tumours, neural and psychiatric disorder studies, breast, prostate, hepatic, gastrointestinal, and genitourinary investigations have been reviewed.

Differential neurometabolite alterations in brains of medication-free individuals with bipolar disorder and those with unipolar depression: a two-dimensional proton magnetic resonance spectroscopy study

OBJECTIVES

Bipolar disorder (BD) is a mental disorder characterized by periods of elevated mood and depression. Many individuals with BD are initially misdiagnosed and treated for unipolar depression (UD). In this study, we report direct comparisons between medication-free individuals with BD and those with UD in terms of the neurometabolites in the anterior cingulate cortex (ACC), medial prefrontal cortex (mPFC), parietal cortex (PC), and posterior cingulate cortex (PCC) of the brain.

METHODS

Participants included medication-free patients with BD or UD, and matched healthy controls. All patients were in the depressive state and had similar symptoms. All subjects were subjected to a multi-voxel proton magnetic resonance spectroscopy procedure with a 3.0 T GE Signa MR scanner. After post-processing, the absolute concentrations of glycerophosphocholine + phosphocholine (GPC + PC), phosphocreatine + creatine (PCr + Cr), Glx (glutamate + glutamine), myo-inositol (MI), and N-acetyl aspartate (NAA) from the above brain regions were compared across the three groups.

RESULTS

Patients with BD showed significantly higher levels of Glx in their ACC, lower GPC + PC, PCr + Cr, MI, and NAA in their PC, and lower NAA in their mPFC, compared to healthy controls; patients with UD presented significantly lower levels of GPC + PC, PCr + Cr, and NAA in their PCC, and lower Glx in their mPFC. All analyzed brain metabolites, except Glx, were significantly lower in the PC of patients with BD, whereas levels of GPC + PC, PCr + Cr, and NAA were significantly reduced in the PCC of patients with UD.

CONCLUSIONS

These results add to the evidence of brain metabolite differences in brains of patients with UD and BD which may be of help in differentiating these two mood disorders.