The primary objectives of these international guidelines were to provide a global audience of clinicians with (a) a series of evidence-based recommendations for the provision of lifestyle-based men...

Objective: Approximately 20% of people with Anorexia Nervosa (AN) and 10% with Bulimia Nervosa (BN) will eventually develop a long‐standing illness. Although there is no set definition for Severe and Enduring eating Disorder (SE‐ED), the common criteria relate to a long duration of the disorder and a number of unsuccessful treatment attempts. Research evidence for treatment of SE‐ED remains limited, thus the objective of this systematic review was to describe different treatment interventions and their effects on SE‐ED‐related outcomes.Method: A systematic search for quantitative treatment studies of adult participants with SE‐ED was conducted in June 2019 (PROSPERO, CRD42018115802) with no restriction on eating disorder type. Altogether, 2,938 studies were included for title and abstract screening.Results: After systematic searches and article screening, 23 studies (3 randomized controlled trials, 3 open‐label studies, 8 naturalistic follow‐up studies, 8 case series and case studies, and 1 partially blinded pilot study) were included in the analysis and data extraction. Methodological quality of the included studies was generally low. Inpatient treatment programs (n = 5) were effective in short‐term symptom reduction, but long‐term results were inconsistent. Outpatient and day‐hospital treatment programs (n = 5) seemed promising for symptom reduction. Drug interventions (n = 5) showed some benefits, especially as adjuvant therapies. Brain stimulation (n = 6) led to improvements in depressive symptoms. Other treatments (n = 2) produced mixed results.Discussion: This is the first systematic review to examine all of the different treatment interventions that have been studied in SE‐ED. The results will inform future interventions in research and clinical practice.

Neurosteroid and immunological actions of vitamin D may regulate depression-linked physiology. Meta‐analyses investigating the effect of vitamin D on depression have been inconsistent. This meta-analysis investigated the efficacy of vitamin D in reducing depressive symptoms among adults in randomized placebo-controlled trials (RCT). General and clinical populations, and studies of ill individuals with systemic diseases were included. Light therapy, co-supplementation (except calcium) and bipolar disorder were exclusionary. Databases Medline, PsycINFO, CINAHL and The Cochrane Library were searched to identify relevant articles in English published before April 2022. Cochrane risk-of-bias tool (RoB 2) and GRADE were used to appraise studies. Forty-one RCTs (n = 53,235) were included. Analyses based on random-effects models were performed with the Comprehensive Meta-analysis Software. Results for main outcome (n = 53,235) revealed a positive effect of vitamin D on depressive symptoms (Hedges’ g = −0.317, 95% CI [−0.405, −0.230], p < 0.001, I² = 88.16%; GRADE: very low certainty). RoB assessment was concerning in most studies. Notwithstanding high heterogeneity, vitamin D supplementation ≥ 2,000 IU/day appears to reduce depressive symptoms. Future research should investigate possible benefits of augmenting standard treatments with vitamin D in clinical depression. PROSPERO registration number: CRD42020149760. Funding: Finnish Medical Foundation, grant 4120 and Juho Vainio Foundation, grant 202100353.

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.

Rapidly accumulating evidence supports the important role of gut microbiome in the regulation of mood, behaviour, appetite, gastrointestinal symptomology, and nutrient metabolism. These are all core features frequently altered in individuals with anorexia nervosa (AN). Current treatment recommendations for AN support the use of high-calorie diets as an essential part of nutritional rehabilitation, commonly achieved by elevating the fat content of the diet. However, in contrast to this approach, there is accumulating evidence suggesting the importance of balanced, high-fibre diets on the gut microbiome. Studies have demonstrated profound differences in the microbial composition of underweight people with AN and those of normal- or overweight individuals. Specific alterations vary widely between studies. It is thus far unclear to what extent the observed differences are brought on by iatrogenic effects of nutritional rehabilitation or the disorder itself. To date, only two studies have investigated the changes in the intestinal microbiota during nutritional rehabilitation and corresponding weight restoration. These studies suggest that the gut microbiome of AN patients was different to healthy controls both prior and following nutritional rehabilitation, though it is noted that these states were associated with lower and higher nutritional intakes, respectively. There is a clear need for further investigation regarding the effects of nutritional rehabilitation on the gut microbiome. Such research would provide insights into the potential role of gut microbiome in modulating the pathophysiology of AN and inform future treatment strategies.