Ketosis and bipolar disorder: controlled analytic study of online reports

Ketogenic diet has a positive association with mental and emotional well-being in the general population

OBJECTIVES

A ketogenic diet reduces pathologic stress and improves mood in neurodegenerative and neurodevelopmental disorders. However, the effects of a ketogenic diet for people from the general population have largely been unexplored. A ketogenic diet is increasingly used for weight loss. Research in healthy individuals primarily focuses on the physical implications of a ketogenic diet. It is important to understand the holistic effects of a ketogenic diet, not only the physiological but also the psychological effects, in non-clinical samples. The aim of this cross-sectional study with multiple cohorts was to investigate the association of a ketogenic diet with different aspects of mental health, including calmness, contentedness, alertness, cognitive and emotional stress, depression, anxiety, and loneliness, in a general healthy population.

METHODS

Two online surveys were distributed: cohort 1 used Bond-Lader visual analog scales and Perceived Stress Scale (n = 147) and cohort 2 the Depression Anxiety Stress Scale and revised UCLA Loneliness Scale (n = 276).

RESULTS

A ketogenic diet was associated with higher self-reported mental and emotional well-being behaviors, including calmness, contentedness, alertness, cognitive and emotional stress, depression, anxiety, and loneliness, compared with individuals on a non-specific diet in a general population.

CONCLUSION

This research found that a ketogenic diet has potential psychological benefits in the general population.

Therapeutic potential of the ketogenic diet: A metabolic switch with implications for neurological disorders, the gut-brain axis, and cardiovascular diseases

The Ketogenic Diet (KD) is a dietary regimen that is low in carbohydrates, high in fats, and contains adequate protein. It is designed to mimic the metabolic state of fasting. This diet triggers the production of ketone bodies through a process known as ketosis. The primary objective of KD is to induce and sustain ketosis, which has been associated with numerous health benefits. Recent research has uncovered promising therapeutic potential for KD in the treatment of various diseases. This includes evidence of its effectiveness as a dietary strategy for managing intractable epilepsy, a form of epilepsy that is resistant to medication. We are currently assessing the efficacy and safety of KD through laboratory and clinical studies. This review focuses on the anti-inflammatory properties of the KD and its potential benefits for neurological disorders and the gut-brain axis. We also explore the existing literature on the potential effects of KD on cardiac health. Our aim is to provide a comprehensive overview of the current knowledge in these areas. Given the encouraging preliminary evidence of its therapeutic effects and the growing understanding of its mechanisms of action, randomized controlled trials are warranted to further explore the rationale behind the clinical use of KD. These trials will ultimately enhance our understanding of how KD functions and its potential benefits for various health conditions. We hope that our research will contribute to the body of knowledge in this field and provide valuable insights for future studies.

Impact of a keto diet on symptoms of Parkinson's disease, biomarkers, depression, anxiety and quality of life: a longitudinal study

Aim: Evidence suggests low-carbohydrate diets (LCHF) may assist in treating neurodegenerative diseases such as Parkinson's disease (PD); however, gaps exist in the literature. Patients & methods: We conducted a small 24-week pilot study to investigate the effects of an LCHF diet on motor and nonmotor symptoms, health biomarkers, anxiety, and depression in seven people with PD. We also captured patient experiences during the process (quality of life [QoL]). Results: Participants reported improved biomarkers, enhanced cognition, mood, motor and nonmotor symptoms, and reduced pain and anxiety. Participants felt improvements enhanced their QoL. Conclusion: We conclude that an LCHF intervention is safe, feasible, and potentially effective in mitigating the symptoms of this disorder. However, more extensive randomized controlled studies are needed to create generalizable recommendations.

Understanding the experiences of ketogenic metabolic therapy for people living with varying levels of depressive symptoms: a thematic analysis

Background

Evidence suggests that a ketogenic diet (KD) may help to alleviate psychiatric symptoms, including depression and anxiety. Positive changes have been reported such as improvements in cognition, concentration, and sleep, a reduction in hunger, and an increase in well-being, energy, confidence, and resilience. This research aims to understand the impact of a non-calorie-restricted KD on depression and aspects of psychological well-being in those with varying degrees of depressive symptoms. Though there are a few studies directly exploring the experiences of those following a KD, this will be the first study to explore the narrative from a mental health and psychological well-being viewpoint.

Method

A sample of nine participants who had followed a non-calorie restricted KD intervention of 50 g of carbohydrates or less per day for at least 12 weeks were recruited. Participants were split into 'healthy adults' group who had no to low depressive symptoms and 'depressive symptoms' group who had mild to moderate depressive symptoms. A reflexive thematic analysis was considered suitable for this study.

Findings

Five core themes and 24 subthemes were created. These were, (1) Poor health prior to program; (2) Hunger and cravings-the food and mood connection; (3) Psychological well-being improvements; (4) It becomes a lifestyle; and (5) Implementation difficulties. Participants experienced mental health improvements such as increased self-esteem, confidence, motivation, and achievement. Some experienced more control in life and a greater sense of reward. Those with depressive symptoms who initially reported low self-worth and hopelessness later reported increased self-esteem and renewed meaning and purpose in life. The findings from this study reflect the previous reports that the diet implementation can be difficult initially, but soon becomes easy to follow and turns into a lifestyle.

Conclusion

In the literature, there are very few qualitative studies that explore the accounts and lived experiences of those following a KD. From the participants' accounts in this study, it appears that the benefits and positive outcomes of this diet outweigh any negative side-effects experienced. This is encouraging for those who are looking for adjunctive therapies to address and improve their depressive symptoms and overall mental health.

Lifestyle modification as intervention for seasonal affective disorder: A systematic review

Bright light therapy (BLT) and pharmacological therapies currently represent the first line treatments for patients with seasonal affective disorder (SAD). Lifestyle modifications offer a diverse field of additional intervention options. Since it is unclear, if lifestyle modifications are effective in SAD patients, this systematic review aims to synthesize the current evidence on their effectiveness and safety. We systematically searched for randomized controlled trials (RCTs) assessing lifestyle modifications (nutrition, exercise, staying outdoors, sleep, social aspects, mindfulness methods) in SAD patients. We defined the primary outcome as the post-therapeutic extent of depressive symptoms, measured by validated psychiatric symptom scales. Due to the insufficient number of studies and the high heterogeneity of the interventions we were not able to calculate a meta-analysis. We identified 6 studies from the following areas of lifestyle modification: diet, exercise, staying outdoors, sleep and music therapy. All studies showed improvements of depression scores in the intervention as well as in the control groups. The risk of bias was rated as high for all studies and the certainty of evidence was rated as very low. The results point towards the possible effectiveness of the interventions examined, but due to the small number of studies found, too small sample sizes and methodological limitations, we cannot draw a valid conclusion about the effectiveness of lifestyle-modifying measures in SAD patients. Larger, high-quality RCTs are needed to make evidence-based recommendations and thus to expand the range of therapeutic options for SAD.

The Potential Effects of the Ketogenic Diet in the Prevention and Co-Treatment of Stress, Anxiety, Depression, Schizophrenia, and Bipolar Disorder: From the Basic Research to the Clinical Practice

BACKGROUND

The ketogenic diet (KD) has been highly developed in the past for the treatment of epileptic pathological states in children and adults. Recently, the current re-emergence in its popularity mainly focuses on the therapy of cardiometabolic diseases. The KD can also have anti-inflammatory and neuroprotective activities which may be applied to the prevention and/or co-treatment of a diverse range of psychiatric disorders.

PURPOSE

This is a comprehensive literature review that intends to critically collect and scrutinize the pre-existing research basis and clinical data of the potential advantageous impacts of a KD on stress, anxiety, depression, schizophrenia and bipolar disorder.

METHODS

This literature review was performed to thoroughly represent the existing research in this topic, as well as to find gaps in the international scientific community. In this aspect, we carefully investigated the ultimate scientific web databases, e.g., PubMed, Scopus, and Web of Science, to derive the currently available animal and clinical human surveys by using efficient and representative keywords.

RESULTS

Just in recent years, an increasing amount of animal and clinical human surveys have focused on investigating the possible impacts of the KD in the prevention and co-treatment of depression, anxiety, stress, schizophrenia, and bipolar disorder. Pre-existing basic research with animal studies has consistently demonstrated promising results of the KD, showing a propensity to ameliorate symptoms of depression, anxiety, stress, schizophrenia, and bipolar disorder. However, the translation of these findings to clinical settings presents a more complex issue. The majority of the currently available clinical surveys seem to be moderate, usually not controlled, and have mainly assessed the short-term effects of a KD. In addition, some clinical surveys appear to be characterized by enormous dropout rates and significant absence of compliance measurement, as well as an elevated amount of heterogeneity in their methodological design.

CONCLUSIONS

Although the currently available evidence seems promising, it is highly recommended to accomplish larger, long-term, randomized, double-blind, controlled clinical trials with a prospective design, in order to derive conclusive results as to whether KD could act as a potential preventative factor or even a co-treatment agent against stress, anxiety, depression, schizophrenia, and bipolar disorder. Basic research with animal studies is also recommended to examine the molecular mechanisms of KD against the above psychiatric diseases.

The Potential Role of the Ketogenic Diet in Serious Mental Illness: Current Evidence, Safety, and Practical Advice

The ketogenic diet (KD) is a high-fat, low-carbohydrate diet that mimics the physiological state of fasting. The potential therapeutic effects in many chronic conditions have led to the gaining popularity of the KD. The KD has been demonstrated to alleviate inflammation and oxidative stress, modulate the gut microbiota community, and improve metabolic health markers. The modification of these factors has been a potential therapeutic target in serious mental illness (SMI): bipolar disorder, major depressive disorder, and schizophrenia. The number of clinical trials assessing the effect of the KD on SMI is still limited. Preliminary research, predominantly case studies, suggests potential therapeutic effects, including weight gain reduction, improved carbohydrate and lipid metabolism, decrease in disease-related symptoms, increased energy and quality of life, and, in some cases, changes in pharmacotherapy (reduction in number or dosage of medication). However, these findings necessitate further investigation through larger-scale clinical trials. Initiation of the KD should occur in a hospital setting and with strict care of a physician and dietitian due to potential side effects of the diet and the possibility of exacerbating adverse effects of pharmacotherapy. An increasing number of ongoing studies examining the KD's effect on mental disorders highlights its potential role in the adjunctive treatment of SMI.

Targeting inflammasome complexes as a novel therapeutic strategy for mood disorders

INTRODUCTION

Inflammasome complexes, especially NLRP3, have gained great attention as a potential therapeutic target in mood disorders. NLRP3 triggers a caspase 1-dependent release of the inflammatory cytokines IL-1β and IL-18, and seems to interact with purinergic and kynurenine pathways, all of which are implicated in mood disorders development and progression.

AREAS COVERED

Emerging evidence supports NLRP3 inflammasome as a promising pharmacological target for mood disorders. We discussed the available evidence from animal models and human studies and provided a reflection on drawbacks and perspectives for this novel target.

EXPERT OPINION

Several studies have supported the involvement of NLRP3 inflammasome in MDD. However, most of the evidence comes from animal models. The role of NLRP3 inflammasome in BD as well as its anti-manic properties is not very clear and requires further exploration. There is evidence of anti-manic effects of P2×R7 antagonists associated with reduction in the brain levels of IL-1β and TNF-α in a murine model of mania. The involvement of other NLRP3 inflammasome expressing cells besides microglia, like astrocytes, and of other inflammasome complexes in mood disorders also deserves further investigation. Preclinical and clinical characterization of NLRP3 and other inflammasomes in mood disorders is needed before considering translational approaches, including clinical trials.

Differentially Altered Metabolic Pathways in the Amygdala of Subjects with Schizophrenia, Bipolar Disorder and Major Depressive Disorder

Background and hypothesis

A growing number of studies implicate a key role for metabolic processes in psychiatric disorders. Recent studies suggest that ketogenic diet may be therapeutically effective for subgroups of people with schizophrenia (SCZ), bipolar disorder (BPD) and possibly major depressive disorder (MDD). Despite this promise, there is currently limited information regarding brain energy metabolism pathways across these disorders, limiting our understanding of how brain metabolic pathways are altered and who may benefit from ketogenic diets. We conducted gene expression profiling on the amygdala, a key region involved in in the regulation of mood and appetitive behaviors, to test the hypothesis that amygdala metabolic pathways are differentially altered between these disorders.

Study Design

We used a cohort of subjects diagnosed with SCZ, BPD or MDD, and non-psychiatrically ill control subjects (n=15/group), together with our bioinformatic 3-pod analysis consisting of full transcriptome pathway analysis, targeted pathway analysis, leading-edge gene analysis and iLINCS perturbagen analysis.

Study Results

We identified differential expression of metabolic pathways in each disorder. Subjects with SCZ displayed downregulation of mitochondrial respiration and nucleotide metabolism pathways. In comparison, we observed upregulation of mitochondrial respiration pathways in subjects with MDD, while subjects with BPD displayed enrichment of pathways involved in carbohydrate metabolism. Several pathways associated with brain metabolism including immune system processes and calcium ion transport were also differentially altered between diagnosis groups.

Conclusion

Our findings suggest metabolic pathways are differentially altered in the amygdala in these disorders, which may impact approaches for therapeutic strategies.

Dietary habits, depression and obesity: an intricate relationship to explore in pediatric preventive strategies

Obesity and depression represent major health problems due to their high prevalence and morbidity rates. Numerous evidences elucidated the connections between dietary habits and the incidence or severity of depression. This overview aims to investigate the intricate relationship between dietary patterns and depression with the objective of elaborating preventive strategies for childhood obesity. Literature data recognized that there is a link between mood and food choices, with certain foods selected for their impact on the brain's reward centers. This behavior parallels the one observed in substance addiction, suggesting a specific neural mechanism for food addiction that contributes to overeating and obesity. It is important to note the significant correlation between obesity and depression, indicating a shared biological pathway influencing these conditions. Stress substantially affects also eating behaviors, often leading to increased consumption of pleasurable and rewarding foods. This can trigger a cycle of overeating, weight gain, and psychological distress, exacerbating mood disorders and obesity. In addition, consumption of certain types of foods, especially "comfort foods" high in fat and calories, may provide temporary relief from symptoms of depression, but can lead to long-term obesity and further mental health problems. Understanding these complex interactions is critical to developing preventive strategies focusing on dietary, emotional, and environmental factors, thereby reducing the risk of obesity and mood disorders.

The impact of ketogenic diet on some metabolic and non-metabolic diseases: Evidence from human and animal model experiments

The ketogenic diet (KD) is recognized as minimum carbohydrate and maximum fat intakes, which leads to ketosis stimulation, a state that is thought to metabolize fat more than carbohydrates for energy supply. KD has gained more interest in recent years and is for many purposes, including weight loss and managing serious diseases like type 2 diabetes. On the other hand, many believe that KD has safety issues and are uncertain about the health drawbacks. Thus, the outcomes of the effect of KD on metabolic and non-metabolic disease remain disputable. The current narrative review aims to evaluate the effect of KD on several diseases concerning the human health. To our best knowledge, the first report aims to investigate the efficacy of KD on multiple human health issues including type 2 diabetes and weight loss, cardiovascular disease, kidney failure and hypertension, non-alcoholic fatty liver, mental problem, oral health, libido, and osteoporosis. The literature searches were performed in Databases, PubMed, Scopus, and web of Science looking for both animal and human model designs. The results heterogeneity seems to be explained by differences in diet composition and duration. Also, the available findings may show that proper control of carbohydrates, a significant reduction in glycemic control and glycated hemoglobin, and weight loss by KD can be an approach to improve diabetes and obesity, hypertension, non-alcoholic fatty liver, PCOS, libido, oral health, and mental problem if isocaloric is considered. However, for some other diseases like cardiovascular disease and osteoporosis, more robust data are needed. Therefore, there is robust data to support the notion that KD can be effective for some metabolic and non-metabolic diseases but not for all of them. So they have to be followed cautiously and under the supervision of health professionals.

Ketogenic therapy towards precision medicine for brain diseases

Precision nutrition and nutrigenomics are emerging in the development of therapies for multiple diseases. The ketogenic diet (KD) is the most widely used clinical diet, providing high fat, low carbohydrate, and adequate protein. KD produces ketones and alters the metabolism of patients. Growing evidence suggests that KD has therapeutic effects in a wide range of neuronal diseases including epilepsy, neurodegeneration, cancer, and metabolic disorders. Although KD is considered to be a low-side-effect diet treatment, its therapeutic mechanism has not yet been fully elucidated. Also, its induced keto-response among different populations has not been elucidated. Understanding the ketone metabolism in health and disease is critical for the development of KD-associated therapeutics and synergistic therapy under any physiological background. Here, we review the current advances and known heterogeneity of the KD response and discuss the prospects for KD therapy from a precision nutrition perspective.

Pilot study of a ketogenic diet in bipolar disorder

BACKGROUND

Recent evidence from case reports suggests that a ketogenic diet may be effective for bipolar disorder. However, no clinical trials have been conducted to date.

AIMS

To assess the recruitment and feasibility of a ketogenic diet intervention in bipolar disorder.

METHOD

Euthymic individuals with bipolar disorder were recruited to a 6-8 week trial of a modified ketogenic diet, and a range of clinical, economic and functional outcome measures were assessed. Study registration number: ISRCTN61613198.

RESULTS

Of 27 recruited participants, 26 commenced and 20 completed the modified ketogenic diet for 6-8 weeks. The outcomes data-set was 95% complete for daily ketone measures, 95% complete for daily glucose measures and 95% complete for daily ecological momentary assessment of symptoms during the intervention period. Mean daily blood ketone readings were 1.3 mmol/L (s.d. = 0.77, median = 1.1) during the intervention period, and 91% of all readings indicated ketosis, suggesting a high degree of adherence to the diet. Over 91% of daily blood glucose readings were within normal range, with 9% indicating mild hypoglycaemia. Eleven minor adverse events were recorded, including fatigue, constipation, drowsiness and hunger. One serious adverse event was reported (euglycemic ketoacidosis in a participant taking SGLT2-inhibitor medication).

CONCLUSIONS

The recruitment and retention of euthymic individuals with bipolar disorder to a 6-8 week ketogenic diet intervention was feasible, with high completion rates for outcome measures. The majority of participants reached and maintained ketosis, and adverse events were generally mild and modifiable. A future randomised controlled trial is now warranted.

Posting patterns in peer online support forums and their associations with emotions and mood in bipolar disorder: Exploratory analysis

BACKGROUND

Mental health (MH) peer online forums offer robust support where internet access is common, but healthcare is not, e.g., in countries with under-resourced MH support, rural areas, and during pandemics. Despite their widespread use, little is known about who posts in such forums, and in what mood states. The discussion platform Reddit is ideally suited to study this as it hosts forums (subreddits) for MH and non-MH topics. In bipolar disorder (BD), where extreme mood states are core defining features, mood influences are particularly relevant.

OBJECTIVES

This exploratory study investigated posting patterns of Reddit users with a self-reported BD diagnosis and the associations between posting and emotions, specifically: 1) What proportion of the identified users posts in MH versus non-MH subreddits? 2) What differences exist in the emotions that they express in MH or non-MH subreddit posts? 3) How does mood differ between those users who post in MH subreddits compared to those who only post in non-MH subreddits?

METHODS

Reddit users were automatically identified via self-reported BD diagnosis statements and all their 2005-2019 posts were downloaded. First, the percentages of users who posted only in MH (non-MH) subreddits were calculated. Second, affective vocabulary use was compared in MH versus non-MH subreddits by measuring the frequency of words associated with positive emotions, anxiety, sadness, anger, and first-person singular pronouns via the LIWC text analysis tool. Third, a logistic regression distinguished users who did versus did not post in MH subreddits, using the same LIWC variables (measured from users' non-MH subreddit posts) as predictors, controlling for age, gender, active days, and mean posts/day.

RESULTS

1) Two thirds of the identified 19,685 users with a self-reported BD diagnosis posted in both MH and non-MH subreddits. 2) Users who posted in both MH and non-MH subreddits exhibited less positive emotion but more anxiety and sadness and used more first-person singular pronouns in their MH subreddit posts. 3) Feminine gender, higher positive emotion, anxiety, and sadness were significantly associated with posting in MH subreddits.

CONCLUSIONS

Many Reddit users who disclose a BD diagnosis use a single account to discuss MH and other concerns. Future work should determine whether users exhibit more anxiety and sadness in their MH subreddit posts because they more readily post in MH subreddits when experiencing lower mood or because they feel more able to express negative emotions in these spaces. MH forums may reflect the views of people who experience more extreme mood (outside of MH subreddits) compared to people who do not post in MH subreddits. These findings can be useful for MH professionals to discuss online forums with their clients. For example, they may caution them that forums may underrepresent people living well with BD.

Ketogenic-Mimicking Diet as a Therapeutic Modality for Bipolar Disorder: Biomechanistic Rationale and Protocol for a Pilot Clinical Trial

There is growing interest in the investigation of ketogenic diets as a potential therapy for bipolar disorder. The overlapping pharmacotherapies utilized for both bipolar disorder and seizures suggest that a mechanistic overlap may exist between these conditions, with fasting and the ketogenic diet representing the most time-proven therapies for seizure control. Recently, preliminary evidence has begun to emerge supporting a potential role for ketogenic diets in treating bipolar disorder. Notably, some patients may struggle to initiate a strict diet in the midst of a mood episode or significant life stressors. The key question addressed by this pilot clinical trial protocol is if benefits can be achieved with a less restrictive diet, as this would allow such an intervention to be accessible for more patients. Recent development of so-called ketone esters, that once ingested is converted to natural ketone bodies, combined with low glycemic index dietary changes has the potential to mimic two foundational components of therapeutic ketosis: high levels of ketones and minimal spiking of glucose/insulin. This pilot clinical trial protocol thus aims to investigate the effect of a 'ketogenic-mimicking diet' (combining supplementation of ketone esters with a low glycemic index dietary intervention) on neural network stability, mood, and biomarker outcomes in the setting of bipolar disorder. Positive findings obtained via this pilot clinical trial protocol may support future target engagement studies of ketogenic-mimicking diets or related ketogenic interventions. A lack of positive findings, in contrast, may justify a focus on more strict dietary interventions for future research.

The Role of the Gut Microbiome in Bipolar Disorder and its Common Comorbidities

Bipolar disorder is a decidedly heterogeneous and multifactorial disease, with significant psychosocial and medical disease burden. Much difficulty has been encountered in developing novel therapeutics and objective biomarkers for clinical use in this population. In that regard, gut-microbial homeostasis appears to modulate several key pathways relevant to a variety of psychiatric, metabolic, and inflammatory disorders. Microbial impact on immune, endocrine, endocannabinoid, kynurenine, and other pathways are discussed throughout this review. Emphasis is placed on this system's relevance to current pharmacology, diet, and comorbid illness in bipolar disorder. Despite the high level of optimism promoted in many reviews on this topic, substantial obstacles exist before any microbiome-related findings can provide meaningful clinical utility. Beyond a comprehensive overview of pathophysiology, this review hopes to highlight several key areas where progress is needed. As well, novel microbiome-associated suggestions are presented for future research.

The Relationship of Ketogenic Diet with Neurodegenerative and Psychiatric Diseases: A Scoping Review from Basic Research to Clinical Practice

BACKGROUND

The ketogenic diet (KD) has become widespread for the therapy of epileptic pathology in childhood and adulthood. In the last few decades, the current re-emergence of its popularity has focused on the treatment of obesity and diabetes mellitus. KD also exerts anti-inflammatory and neuroprotective properties, which could be utilized for the therapy of neurodegenerative and psychiatric disorders.

PURPOSE

This is a thorough, scoping review that aims to summarize and scrutinize the currently available basic research performed in in vitro and in vivo settings, as well as the clinical evidence of the potential beneficial effects of KD against neurodegenerative and psychiatric diseases. This review was conducted to systematically map the research performed in this area as well as identify gaps in knowledge.

METHODS

We thoroughly explored the most accurate scientific web databases, e.g., PubMed, Scopus, Web of Science, and Google Scholar, to obtain the most recent in vitro and in vivo data from animal studies as well as clinical human surveys from the last twenty years, applying effective and characteristic keywords.

RESULTS

Basic research has revealed multiple molecular mechanisms through which KD can exert neuroprotective effects, such as neuroinflammation inhibition, decreased reactive oxygen species (ROS) production, decreased amyloid plaque deposition and microglial activation, protection in dopaminergic neurons, tau hyper-phosphorylation suppression, stimulating mitochondrial biogenesis, enhancing gut microbial diversity, restoration of histone acetylation, and neuron repair promotion. On the other hand, clinical evidence remains scarce. Most existing clinical studies are modest, frequently uncontrolled, and merely assess the short-term impacts of KD. Moreover, several clinical studies had large dropout rates and a considerable lack of compliance assessment, as well as an increased level of heterogeneity in the study design and methodology.

CONCLUSIONS

KD can exert substantial neuroprotective effects via multiple molecular mechanisms in various neurodegenerative and psychiatric pathological states. Large, long-term, randomized, double-blind, controlled clinical trials with a prospective design are strongly recommended to delineate whether KD may attenuate or even treat neurodegenerative and psychiatric disease development, progression, and symptomatology.

Efficacy of low carbohydrate and ketogenic diets in treating mood and anxiety disorders: systematic review and implications for clinical practice

BACKGROUND

There is mounting interest in the potential efficacy of low carbohydrate and very low carbohydrate ketogenic diets in various neurological and psychiatric disorders.

AIMS

To conduct a systematic review and narrative synthesis of low carbohydrate and ketogenic diets (LC/KD) in adults with mood and anxiety disorders.

METHOD

MEDLINE, Embase, PsycINFO and Cochrane databases were systematically searched for articles from inception to 6 September 2022. Studies that included adults with any mood or anxiety disorder treated with a low carbohydrate or ketogenic intervention, reporting effects on mood or anxiety symptoms were eligible for inclusion. PROSPERO registration CRD42019116367.

RESULTS

The search yielded 1377 articles, of which 48 were assessed for full-text eligibility. Twelve heterogeneous studies (stated as ketogenic interventions, albeit with incomplete carbohydrate reporting and measurements of ketosis; diet duration: 2 weeks to 3 years; n = 389; age range 19 to 75 years) were included in the final analysis. This included nine case reports, two cohort studies and one observational study. Data quality was variable, with no high-quality evidence identified. Efficacy, adverse effects and discontinuation rates were not systematically reported. There was some evidence for efficacy of ketogenic diets in those with bipolar disorder, schizoaffective disorder and possibly unipolar depression/anxiety. Relapse after discontinuation of the diet was reported in some individuals.

CONCLUSIONS

Although there is no high-quality evidence of LC/KD efficacy in mood or anxiety disorders, several uncontrolled studies suggest possible beneficial effects. Robust studies are now needed to demonstrate efficacy, to identify clinical groups who may benefit and whether a ketogenic diet (beyond low carbohydrate) is required and to characterise adverse effects and the risk of relapse after diet discontinuation.

Effect of low-carbohydrate diet on depression and anxiety: A systematic review and meta-analysis of controlled trials

BACKGROUND

Despite considerable advances in pharmacological and non-pharmacological treatments, mental health illnesses carry many economic and social burdens. Depression and anxiety are known as mental disorders which are highly prevalent worldwide. Previous studies have shown different results. This diet has attracted enormous interest.

OBJECTIVE

This is the first meta-analysis conducted to review systematically all trials to evaluating the effect of a low carbohydrate diet (LCD) on depression, and anxiety.

METHODS

PubMed, Web of Science, and Scopus have been searched until 9 September 2021. In total, 8 RCTs (n = 590) were carried out for evaluation the effects of LCDs on depression and anxiety were included. All the trials included in the analyses evaluated patients without a mood disorder. Random model effects meta-analysis was conducted. To evaluate the heterogeneity among the included studies. The egger test was used. Subgroup analyses performed based on regions, assessment methods, carbohydrate intake and duration of studies.

RESULTS

This study did not show any significant association between a low carbohydrate diet and the of anxiety (SMD = 0.19, 95 % CI -0.10, 0.47; P = 0.20) and also depression (SMD = 0.06, 95 % CI -0.11, 0.24; P = 0.49). If one of the studies is excluded, this diet significantly increases anxiety (SMD = 0.33, 95 % CI 0.12, 0.54; P ≤ 0.001). This study showed that this diet increases anxiety in studies with <26 % carbohydrate intake (SMD = 0.31; 95%CI 0.10, 0.52; P ≤ 0.001; I² = 0.00, P = 0.52), in the Australia (SMD = 0.29; 95%CI 0.08, 0.49; P = 0.01; I² = 0.00, P = 0.42), and in studies that used the Spielberger State Anxiety Inventory (SAI) to assess anxiety (SMD = 0.33; 95%CI 0.11, 0.54; P ≤ 0.001; I² = 0.00, P = 0.54).

LIMITATIONS

One of the limitations of intervention studies examining the effect of diet is that it is difficult to blind people under intervention.

CONCLUSION

The present study did not demonstrate significant association between a low carbohydrate diet and improvement of depression and anxiety. More accurate studies are needed to reach definitive conclusions.

Ketogenic Diet and Inflammation: Implications for Mood and Anxiety Disorders

The ketogenic diet, known as a low-carbohydrate, high-protein, and high-fat diet, drastically restrains the major source of energy for the body, forcing it to burn all excess fat through a process called ketosis-the breaking down of fat into ketone bodies. First suggested as a medical treatment for children suffering from epilepsy, this diet has gained increased popularity as a rapid weight loss strategy. Over the past few years, there have been numerous studies suggesting that the ketogenic diet may provide therapeutic effects for several psychiatric conditions such as mood- and anxiety-related disorders. However, despite significant progress in research, the mechanisms underlying its therapeutic effects remain largely unexplored and are yet to be fully elucidated. This chapter provides an in-depth overview of preclinical and clinical evidence supporting the use of a ketogenic diet in the management of mood and anxiety disorders and discusses its relationship with inflammatory processes and potential mechanisms of actions for its therapeutic effects.

Ketogenic diet for human diseases: the underlying mechanisms and potential for clinical implementations

The ketogenic diet (KD) is a high-fat, adequate-protein, and very-low-carbohydrate diet regimen that mimics the metabolism of the fasting state to induce the production of ketone bodies. The KD has long been established as a remarkably successful dietary approach for the treatment of intractable epilepsy and has increasingly garnered research attention rapidly in the past decade, subject to emerging evidence of the promising therapeutic potential of the KD for various diseases, besides epilepsy, from obesity to malignancies. In this review, we summarize the experimental and/or clinical evidence of the efficacy and safety of the KD in different diseases, and discuss the possible mechanisms of action based on recent advances in understanding the influence of the KD at the cellular and molecular levels. We emphasize that the KD may function through multiple mechanisms, which remain to be further elucidated. The challenges and future directions for the clinical implementation of the KD in the treatment of a spectrum of diseases have been discussed. We suggest that, with encouraging evidence of therapeutic effects and increasing insights into the mechanisms of action, randomized controlled trials should be conducted to elucidate a foundation for the clinical use of the KD.

Depressive symptoms improve over 2 years of type 2 diabetes treatment via a digital continuous remote care intervention focused on carbohydrate restriction

Depressive symptoms are prevalent among people with type 2 diabetes (T2D) and, even at low severity levels, are associated with worse diabetes outcomes. Carbohydrate restriction is an effective treatment for T2D but its long-term impacts on depressive symptoms are unclear. In the current study we explored changes in depressive symptoms over 2 years among 262 primarily non-depressed T2D patients participating in a continuous remote care intervention emphasizing carbohydrate restriction. Subclinical depressive symptoms decreased over the first 10 weeks and reductions were maintained out to 2 years. Increased frequency of blood ketone levels indicative of adherence to low carbohydrate eating predicted decreases in depressive symptoms. Concerns have been raised with recommending restrictive diets due to potential negative impacts on quality-of-life factors such as mood; however, results of the current study support positive rather than negative long-term impacts of closely monitored carbohydrate restriction on depressive symptoms.

The use of the ketogenic diet in the treatment of psychiatric disorders

INTRODUCTION

The ketogenic diet (KD) is a high-fat, low-carbohydrate, and moderate-protein diet that has shown benefit as a treatment in neurologic disorders and may serve as a therapeutic option in individuals with psychiatric disorders.

METHODS

A search was conducted using EBSCOhost and PubMed databases for studies relating to ketogenic or low-carbohydrate diets and psychiatric disorders.

RESULTS

A total of 32 experimental or observational studies were identified by initial search strategies, 14 of which met the criteria to be included in this analysis. Although specific diet formulations varied somewhat between studies, they all generally examined low-carbohydrate dietary intake with the goal of producing a ketotic state. The studies included in this review indicated the KD was beneficial in reducing symptoms associated with various psychiatric disorders.

DISCUSSION

This review summarizes the available evidence regarding the efficacy of the ketogenic diet in psychiatric disease states. Data from the studies analyzed demonstrated a positive response in individuals who were able to remain on the diet, regardless of the disease state. However, there is a need for more data to clearly define the specific benefits the KD may provide.

Nutrition-based interventions for mood disorders

Introduction: 'Nutritional Psychiatry' is an emerging area of research that has great potential as an adjunctive tool for the prevention and treatment of diverse neuropsychiatric disorders. Several nutrition-related aspects, such as obesity, dietary patterns, gut microbiome composition and gut permeability, bioactive food compounds, and nutrients can influence pathways implicated in the pathophysiology of mood disorders.Areas covered: Here, the authors review the current evidence on nutrition-mood interaction and nutrition-based treatments for the two main mood disorders, i.e., major depressive disorder and bipolar disorder.Expert opinion: Consistent evidence from observational studies has pointed out the association between a 'healthy' diet, generally characterized by a higher intake of fruits, vegetables, legumes, nuts, whole grains, and good quality sources of protein (i.e. fish and/or seafood), and decreased risk of mood disorders and the parallel association between a 'Western' diet pattern and increased risk. However, only a few clinical trials have evaluated the effect of nutritional interventions on the treatment of these conditions. The bidirectional interaction between the brain and the gut, named 'brain-gut-microbiome axis' or 'gut-brain axis', plays a key role in the link between nutrition and mood disorders. Therefore, nutrition-based strategies for gut microbiota modulation are promising fields in mood disorders.

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.

The Role of Mitochondria in Mood Disorders: From Physiology to Pathophysiology and to Treatment

Mitochondria are cellular organelles involved in several biological processes, especially in energy production. Several studies have found a relationship between mitochondrial dysfunction and mood disorders, such as major depressive disorder and bipolar disorder. Impairments in energy production are found in these disorders together with higher levels of oxidative stress. Recently, many agents capable of enhancing antioxidant defenses or mitochondrial functioning have been studied for the treatment of mood disorders as adjuvant therapy to current pharmacological treatments. A better knowledge of mitochondrial physiology and pathophysiology might allow the identification of new therapeutic targets and the development and study of novel effective therapies to treat these specific mitochondrial impairments. This could be especially beneficial for treatment-resistant patients. In this article, we provide a focused narrative review of the currently available evidence supporting the involvement of mitochondrial dysfunction in mood disorders, the effects of current therapies on mitochondrial functions, and novel targeted therapies acting on mitochondrial pathways that might be useful for the treatment of mood disorders.

The Ketogenic Diet for the Treatment of Mood Disorders in Comorbidity With Epilepsy in Children and Adolescents

The ketogenic diet, used for over a century as an alternative therapy for the control of drug-resistant seizures in both children and adults, has recently drawn increasing interest in various neurological or psychiatric disorders other than epilepsy. In particular, there are a few preliminary studies in mood and neurodevelopmental disorders such as anxiety, depression and autism spectrum disorders. Mood disorders in comorbidity with epilepsy are commonly seen in adolescents and young adults both at the onset and during the course of the epileptic disorder. The rationale for the use of the ketogenic diet is based on the potential mood stabilizing effects through level modifications of metabolites such as dopamine and serotonin and the regulation of GABA/glutamatergic neurotransmission, mitochondrial function and oxidative stress. In this review, epilepsies with a higher risk of mood disorders in adolescents will be considered. A brief overview of the various types of ketogenic diet that can currently be offered to young patients in order to improve palatability and compliance with the diet, is also included. The efficacy and tolerability of the ketogenic diet options for the treatment of mood disorders, with or without drug therapy including mood stabilizers and antidepressant drugs, are as well discussed.

Translating big data to better treatment in bipolar disorder - a manifesto for coordinated action

Bipolar disorder (BD) is a major healthcare and socio-economic challenge. Despite its substantial burden on society, the research activity in BD is much smaller than its economic impact appears to demand. There is a consensus that the accurate identification of the underlying pathophysiology for BD is fundamental to realize major health benefits through better treatment and preventive regimens. However, to achieve these goals requires coordinated action and innovative approaches to boost the discovery of the neurobiological underpinnings of BD, and rapid translation of research findings into development and testing of better and more specific treatments. To this end, we here propose that only a large-scale coordinated action can be successful in integrating international big-data approaches with real-world clinical interventions. This could be achieved through the creation of a Global Bipolar Disorder Foundation, which could bring government, industry and philanthropy together in common cause. A global initiative for BD research would come at a highly opportune time given the seminal advances promised for our understanding of the genetic and brain basis of the disease and the obvious areas of unmet clinical need. Such an endeavour would embrace the principles of open science and see the strong involvement of user groups and integration of dissemination and public involvement with the research programs. We believe the time is right for a step change in our approach to understanding, treating and even preventing BD effectively.

Consumer Reports of "Keto Flu" Associated With the Ketogenic Diet

Background: The ketogenic diet (KD) is a high-fat, low-carbohydrate diet that limits glucose and results in the production of ketones by the liver and their uptake as an alternative energy source by the brain. KD is an evidence-based treatment for intractable epilepsy. KD is also self-administered, with limited evidence of efficacy, for conditions including weight loss, cognitive and memory enhancement, type II diabetes, cancer, neurological and psychiatric disorders. A commonly discussed side effect of KD in media and online forums is “keto flu,” a cluster of transient symptoms generally reported as occurring within the first few weeks of KD. This study aimed to characterize the pattern of symptoms, severity and time course of keto flu as related by users of online forums.

Method: Online forums referring to “keto flu,” “keto-induction,” or “keto-adaptation” in the URL were identified in Google. Passages describing personal experiences of keto flu were categorized manually with reference to pattern of symptoms, severity, time course, and remedies proposed.

Results: The search criteria identified 75 online forums, 43 met inclusion criteria and contained 448 posts from 300 unique users. Seventy-three made more than one post (mean 3.12, range 2–11). Descriptors of personal experience of keto flu, reported by 101 of 300 users, included 256 symptom descriptions involving 54 discrete symptoms. Commonest symptoms were “flu,” headache, fatigue, nausea, dizziness, “brain fog,” gastrointestinal discomfort, decreased energy, feeling faint and heartbeat alterations. Symptom reports peaked in the first and dwindled after 4 weeks. Resolution of keto flu symptoms was reported by eight users between days 3 and 30 (median 4.5, IQR 3–15). Severity of symptoms, reported by 60 users in 40 forums, was categorized as mild (N = 15), moderate (N = 23), or severe (N = 22). Eighteen remedies were proposed by 121 individual users in 225 posts.

Conclusions: Typically, individual posts provided fragmentary descriptions related to the flow of forum conversations. A composite picture emerged across 101 posts describing personally experienced symptoms. User conversations were generally supportive, sharing remedies for keto flu reflecting assumptions of physiological effects of KD.

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.

The gut microbiome and neuropsychiatric disorders: implications for attention deficit hyperactivity disorder (ADHD)

Neuropsychiatric disorders (NPDs) such as depression, anxiety, bipolar disorder, autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) all relate to behavioural, cognitive and emotional disturbances that are ultimately rooted in disordered brain function. More specifically, these disorders are linked to various neuromodulators (i.e. serotonin and dopamine), as well as dysfunction in both cognitive and socio-affective brain networks. Increasing evidence suggests that the gut environment, and particularly the microbiome, plays a significant role in individual mental health. Although the presence of a gut-brain communication axis has long been established, recent studies argue that the development and regulation of this axis is dictated by the gut microbiome. Many studies involving both animals and humans have connected the gut microbiome with depression, anxiety and ASD. Microbiome-centred treatments for individuals with these same NPDs have yielded promising results. Despite its recent rise and underlying similarities to other NPDs, both biochemically and symptomatically, connections between the gut microbiome and ADHD currently lag behind those for other NPDs. We demonstrate that all evidence points to the importance of, and dire need for, a comprehensive and in-depth analysis of the role of the gut microbiome in ADHD, to deepen our understanding of a condition that affects millions of individuals worldwide.

A pyruvate dehydrogenase complex disorder hypothesis for bipolar disorder

Ketosis is a metabolic state in which the body uses ketones derived from breakdown of fatty acids as the primary mitochondrial fuel source instead of glucose. In recent years an accumulation of evidence for the beneficial effects of the ketotic state on the brain have heightened interest in its potential for use in neurological conditions. The ketogenic diet (KD) induces ketosis and is an effective treatment for medically resistant epilepsy. There is significant comorbidity between epilepsy and bipolar disorder (BD) and both conditions are treated by anti-convulsant drugs. In addition, reports on bipolar disease online fora have highlighted subjective mood stabilization effects associated with the KD. These KD reported effects could be explained if there was a disorder in the conversion of pyruvate into Acetyl-CoA (and subsequent impairment of oxidative phosphorylation) which was bypassed by ketones providing an alternative substrate for oxidative phosphorylation. This is consistent with growing evidence that mitochondrial dysfunction plays a causal role in BD and explains the reported TCA cycle dysfunction and elevated pyruvate levels in BD. Reduced levels of ATP affects the normal operation of the Na, K-ATPase in the brain with differing levels of reduction either leading to reduced neuronal action potential and inhibition of neurotransmitter release (consistent with the depressed state in BD) or increased neuronal resting potential and hyper-excitability (consistent with a [hypo]manic mood state). We hypothesize that the mitochondrial dysfunction is due to a disorder of the Pyruvate Dehydrogenase Complex (PDC) and/or Mitochondrial Carrier Protein (MCP) shuttle which moves intracellular pyruvate into mitochondria. The resultant reduction in ATP generation could explain mood instability and cycling in BD (through mechanisms such as those delineated by Mallakh and Peters). This proposed novel causal pathway could explain mood de-stabilization in BD and the reported positive effects of KD. If true, this hypothesis would suggest that there should be increased research attention to PDC (and in particular the E1 alpha subunit) as potential therapeutic targets and further study of a possible role of KD in BD to improve mood stability. Experimental approaches, such as through a clinical trial of KD on mood stabilization in BD, are required to further investigate this hypothesis.