Wheat gluten challenge in schizophrenic patients

Randomized Double Blind Inpatient Study of a Gluten-Free Diet in Persons with Schizophrenia

Background

Schizophrenia and related disorders (SRD) are characterized by positive and negative symptoms, such as anhedonia and avolition. There are no current FDA approved treatments for negative symptoms, which is a critical gap in our treatment of people with SRDs, since they are a major determinant of functional impairment. An emerging literature suggests that SRDs have a relationship with immune function and inflammation. Recently an SRD subgroup with high inflammation and elevated levels of anti-gliadin antibodies (AGA) of immunoglobulin G type (IgG) has been characterized. Negative symptom improvement has been previously observed with gluten removal in this subgroup in two small clinical trials.

Methods

We conducted a 5-week confirmatory double-blind placebo-controlled trial of a gluten free diet (GFD) versus gluten-containing diet (GCD) for negative symptoms in people with SRD who have elevated AGA IgG (NCT03183609). Participants were between the ages of 18-64 years, had baseline negative symptoms and a diagnosis of schizophrenia or schizoaffective disorder. Those included were screened for an AGA IgG >20 U, no serologic evidence of celiac disease, and stable antipsychotic treatment and dose. All participants were inpatients, received a GFD and were randomized to 30 grams of gluten or rice flour daily delivered in protein shakes. The Clinical Assessment Interview for Negative Symptoms (CAINS) Motivation and Pleasure (MAP) scale was the primary outcome measure. We also examined the CAINS Expressivity (EXP) scale, the Scale for the Assessment of Negative Symptoms (SANS), the Brief Psychiatric Rating Scale (BPRS), the MATRICS Consensus Cognitive Battery (MCCB) and conducted regular side effect screening and laboratory measures for safety.

Findings

Between 2018 and 2024, we included 39 participants (N=21 GFD and N=18 GCD). There was a significant improvement over time in the CAINS MAP (treatment X time df=30.1, F=2.78, p=0.045) in the GFD compared to GCD, but no significant change in the CAINS EXP, the SANS, BPRS or MCCB. The diet was well tolerated; the most frequently occurring side effects were constipation (38.1% GFD, 33.3% GCD), sedation (33.3% GFD, 50% GCD), dry mouth (33.3% GFD, 33.3% GCD), headache (33.3% GFD, 27.8% GCD), and insomnia (33.3% GFD, 27.8% GCD).

Interpretation

This is the first large scale double-blind randomized clinical trial in SRD with AGA IgG+. This replication of smaller studies suggests that negative symptoms, particularly anhedonia and avolition may be improved. However, we did not replicate our previous finding of cognitive improvement and COVID-19 likely impacted the extent of improvement in negative symptoms due to quarantines and lockdowns. More work is needed to determine the mechanism of action of gluten removal in this subgroup with hopes of developing new treatment targets for motivational deficits of this illness.

Funding

This project was funded by NIMH R01 R01MH113617 (DL Kelly PI).

Nutrition, nutritional deficiencies, and schizophrenia: An association worthy of constant reassessment

Schizophrenia is a mental health disorder that occurs worldwide, cutting across cultures, socioeconomic groups, and geographical barriers. Understanding the details of the neurochemical basis of schizophrenia, factors that contribute to it and possible measures for intervention are areas of ongoing research. However, what has become more evident is the fact that in targeting the neurochemical imbalances that may underlie schizophrenia, the type of response seen with currently available phamacotherapeutic agents does not provide all the answers that are needed. Therefore, the possible contribution of non-pharmacological approaches to schizophrenia management is worthy of consideration. In recent times, research is beginning to show nutrition may play a possibly significant role in schizophrenia, affecting its development, progression and management; however, while attempts had been made to examine this possible relationship from different angles, articles addressing it from a holistic point of view are not common. In this review, we examine existing scientific literature dealing with the possible relationship between nutrition and schizophrenia, with a view to elucidating the impact of diet, nutritional deficiencies and excesses on the aetiology, progression, management and outcome of schizophrenia. Secondly, the effect of nutritional supplements in prevention, as sole therapy, or adjuncts in schizophrenia management are examined.

Opioid system influences gut-brain axis: Dysbiosis and related alterations

Opioid drugs are widely used to treat chronic pain, but their misuse can lead to tolerance, dependence, and addiction and have created a significant public health problem. In addition, food-derived opioid peptides, known as exorphins, like gluten exorphins have been shown to have harmful effects in certain pathologies like celiac disease, for example. Several studies support the involvement of the opioid system in the development of disorders such as autism spectrum syndrome. Moreover, bidirectional communication between the intestine and brain has been shown to be altered in various neurodegenerative diseases including Alzheimer´s and Parkinson´s. The presence of opioid receptors in both the digestive tract and the central nervous system (CNS) suggests that opioid drugs and exorphins may modulate the gut-brain axis. Morphine, for example, has shown a dysbiotic effect on the bacterial microbiota in addition to inducing an increase in intestinal permeability facilitating bacterial translocation. Furthermore, certain components of bacteria can modify the expression of opioid receptors at the central level increasing sensitivity to pain. Strategies based on use of probiotics have resulted in improvements in symptoms of autism and Parkinson´s disease. In this manuscript, we review the role of the opioid system in disorders and CNS pathologies and the involvement of the gut-brain axis.

Going Against the Grains: Gluten-Free Diets in Patients Without Celiac Disease-Worthwhile or Not?

While the gluten-free diet (GFD) is the only known effective therapy for celiac disease, in recent years it has become increasingly popular in the USA and worldwide, with many believing it to be more "healthful" and others claiming that it has beneficial effects for health conditions, many extraintestinal, other than celiac disease. This review examines the evidence for use of the GFD in patients without celiac disease who self-report intestinal and/or extraintestinal symptoms (non-celiac gluten sensitivity), as well as for enhancement of athletic performance and treatment of autism, rheumatoid arthritis, and psychiatric disorders. Overall, the evidence for use of GFDs in conditions other than celiac disease is poor. Though non-celiac gluten sensitivity may ultimately emerge as a biomarker-defined condition, a large proportion of patients with apparent non-celiac gluten sensitivity have, after careful investigation, an alternative diagnosis. In light of this, and coupled with the potential physical and psychological harms associated with the avoidance of gluten, initiating a GFD should not be encouraged for people who have these other conditions or are seeking physical/athletic enhancement.

Randomized controlled trial of a gluten-free diet in patients with schizophrenia positive for antigliadin antibodies (AGA IgG): a pilot feasibility study

BACKGROUND

Approximately one-third of people with schizophrenia have elevated levels of anti-gliadin antibodies of the immunoglobulin G type (AGA IgG) — a higher rate than seen in healthy controls. We performed the first double-blind clinical trial of gluten-free versus gluten-containing diets in a subset of patients with schizophrenia who were positive for AGA IgG.

METHODS

In this pilot feasibility study, 16 participants with schizophrenia or schizoaffective disorder who had elevated AGA IgG (≥ 20 U) but were negative for celiac disease were admitted to an inpatient unit for a 5-week trial. All participants received standardized gluten-free meals and were randomized in a double-blind fashion to receive a shake containing 10 g of gluten flour or 10 g of rice flour each day. Participants were rated for psychiatric, cognitive and gastrointestinal symptoms at baseline and endpoint.

RESULTS

Of the 16 participants, 14 completed the 5-week trial (2 discontinued early for administrative reasons). Compared with participants on the gluten-containing diet, participants on the gluten-free diet showed improvement on the Clinical Global Impressions scale (Cohen d = –0.75) and in negative symptoms (Cohen d = –0.53). We noted no improvement in positive or global cognitive symptoms, but did observe an improvement in attention favouring the gluten-free diet (Cohen d = 0.60). Robust improvements in gastrointestinal adverse effects occurred in the gluten-free group relative to the glutencontaining group. Adverse effects were similar between groups.

LIMITATIONS

This study was limited by its small sample size; larger studies are needed.

CONCLUSION

This feasibility study suggests that removal of gluten from the diet is associated with improvement in psychiatric and gastrointestinal symptoms in people with schizophrenia or schizoaffective disorder.

Use of a Gluten-Free Diet in Schizophrenia: A Systematic Review

We performed a systematic review of the literature to determine whether adherence to a gluten-free diet (GFD) leads to improved outcomes for patients with schizophrenia. We searched the AMED (Allied and Complementary Medicine; 1985-June 2016), MEDLINE (1946-June 2016), and Embase (1980-2016 week 24) databases using the terms "wheat" or "glutenin" or "gliadin" or "gluten" AND "schizophrenia." A total of 9 studies met the inclusion criteria for this review: 1 randomized controlled trial, 7 crossover studies, and 1 open-label pilot study. Six of the included studies demonstrated beneficial effects including improved functioning and decreased symptom severity after the course of a GFD, whereas 3 studies found no benefits. All of the included studies found that a GFD is well tolerated and can be adhered to by patients with schizophrenia. The findings of this systematic review should be interpreted with caution due to limitations inherent to nonrandomized trials, as well as the heterogeneity in the study design and the length of the GFD applied in each study. Publication bias is another potential limitation. Further research is required to examine the biomarkers of gluten sensitivity and inflammation to effectively target those patients with schizophrenia who will benefit most from this dietary intervention.

A review on the relationship between gluten and schizophrenia: Is gluten the cause?

INTRODUCTION

Schizophrenia is a chronic disease that possesses various clinical manifestations. It presents rather heterogeneous characteristics with respect to onset type, symptoms, and the course of the disease. Although the lifetime prevalence is as low as 1%, it can cause serious disability. Thus, it is very important to develop efficient treatment methods. In some studies, it is hypothesized that removing gluten from the diet leads to a significant improvement in disease symptoms. Epidemiological studies revealed that the prevalence of celiac disease among schizophrenic patients is almost two times higher than that of the general population.

OBJECTIVE

In this review, we evaluate the effects of gluten and celiac disease on the onset of schizophrenia. Efficacy of gluten-free diet applications, antibody response against gluten, and the interaction of the brain-gut axis and the presence of common genetic points are also investigated.

METHODS

Without any publication date restriction, Pubmed database searches were made for 'schizophrenia, gluten, gliadin, celiac disease, exorphin, brain-gut axis, psychiatric disorders.' The keywords and the articles about the schizophrenia-celiac disease relationship are included in our review.

RESULTS

Several studies presented evidence to suggest that symptoms associated with schizophrenia were minimized when gluten was excluded from patients' diets. Immunological searches revealed that most schizophrenic patients with increased anti-gliadin antibodies did not possess celiac disease; yet, the presence of increased antibodies against gliadin can be the share point of the immunological abnormalities found in both of the diseases.

DISCUSSION

There were no consistent results in the clinical, immunological, microbiological, and epidemiological studies that investigated the relationship between schizophrenia and celiac disease. This presents a need for a larger scale study to confirm the presence of this suggested correlation between schizophrenia and celiac disease. The underlying mechanisms between the two diseases should be explored.

Autoimmune diseases, gastrointestinal disorders and the microbiome in schizophrenia: more than a gut feeling

Autoimmunity, gastrointestinal (GI) disorders and schizophrenia have been associated with one another for a long time. This paper reviews these connections and provides a context by which multiple risk factors for schizophrenia may be related. Epidemiological studies strongly link schizophrenia with autoimmune disorders including enteropathic celiac disease. Exposure to wheat gluten and bovine milk casein also contribute to non-celiac food sensitivities in susceptible individuals. Co-morbid GI inflammation accompanies humoral immunity to food antigens, occurs early during the course of schizophrenia and appears to be independent from antipsychotic-generated motility effects. This inflammation impacts endothelial barrier permeability and can precipitate translocation of gut bacteria into systemic circulation. Infection by the neurotropic gut pathogen, Toxoplasma gondii, will elicit an inflammatory GI environment. Such processes trigger innate immunity, including activation of complement C1q, which also functions at synapses in the brain. The emerging field of microbiome research lies at the center of these interactions with evidence that the abundance and diversity of resident gut microbiota contribute to digestion, inflammation, gut permeability and behavior. Dietary modifications of core bacterial compositions may explain inefficient gluten digestion and how immigrant status in certain situations is a risk factor for schizophrenia. Gut microbiome research in schizophrenia is in its infancy, but data in related fields suggest disease-associated altered phylogenetic compositions. In summary, this review surveys associative and experimental data linking autoimmunity, GI activity and schizophrenia, and proposes that understanding of disrupted biological pathways outside of the brain can lend valuable information regarding pathogeneses of complex, polygenic brain disorders.

Bread and Other Edible Agents of Mental Disease

Perhaps because gastroenterology, immunology, toxicology, and the nutrition and agricultural sciences are outside of their competence and responsibility, psychologists and psychiatrists typically fail to appreciate the impact that food can have on their patients' condition. Here we attempt to help correct this situation by reviewing, in non-technical, plain English, how cereal grains-the world's most abundant food source-can affect human behavior and mental health. We present the implications for the psychological sciences of the findings that, in all of us, bread (1) makes the gut more permeable and can thus encourage the migration of food particles to sites where they are not expected, prompting the immune system to attack both these particles and brain-relevant substances that resemble them, and (2) releases opioid-like compounds, capable of causing mental derangement if they make it to the brain. A grain-free diet, although difficult to maintain (especially for those that need it the most), could improve the mental health of many and be a complete cure for others.

Extraintestinal manifestations of coeliac disease

Coeliac disease is a common disorder that can arise at any age and typically presents with a broad spectrum of symptoms. The disease is thought to be underdiagnosed, in part owing to the fact that coeliac disease is often characterized by associated conditions and extraintestinal manifestations that can misdirect and impede diagnosis. Some of these manifestations are direct consequences of autoimmunity, such as dermatitis herpetiformis or gluten ataxia, whereas others are indirectly related to inflammation and/or malabsorption including anaemia, osteoporosis, short stature and delayed puberty. Any organ from the central nervous system to joints, liver or teeth can be affected. In some cases, extraintestinal symptoms are the only clinical manifestations of coeliac disease or occur in conjunction with diarrhoea and malabsorptive symptoms. An increased awareness among medical practitioners of the variety of extraintestinal manifestations of coeliac disease is essential to improve diagnosis and treatment.

Non-celiac gluten hypersensitivity: What is all the fuss about?

Non-celiac gluten sensitivity (NCGS) has been introduced recently as a potentially common disease on the basis of studies of patients with claimed reactivity to gluten but without the characteristics of celiac disease (CD). CD is characterized by antibody reactivity toward the autoantigen transglutaminase 2, characteristic histological abnormalities of the small intestine, and an almost obligatory genetic haplotype (HLA-DQ2 or DQ8). The diagnosis of NCGS is based largely on the clinical suspicion of hyper-reactivity to gluten and the absence of the characteristics of CD. Few published studies have used double-blind placebo-controlled food challenges (DBPCFCs) for the diagnosis of NCGS, and none in children. Innate immune reactivity to amylase trypsin inhibitors has been suggested as the pathogenic principle in NCGS, but confirmatory evidence is lacking. Also, further clinical studies including DBPCFCs are needed.

Behavioral effects of food-derived opioid-like peptides in rodents: Implications for schizophrenia?

Dohan proposed that an overload of dietary peptides, such as those derived from wheat gluten and milk casein, could be a factor relevant to the development or maintenance of schizophrenia (SZ) symptoms in at least a subset of vulnerable individuals. Rodent behavioral models may offer insight into the plausibility of Dohan's exorphin hypothesis by providing a means to directly study the effects of such peptides. Accordingly, a review of the literature on the behavioral effects of food-derived opioid-like peptides in rodents was undertaken. Studies using a variety of behavioral tests to examine the effects of several classes of food-derived opioid-like peptides were identified and reviewed. Peptides derived from casein (β-casomorphins; BCMs, n=19), spinach (rubiscolins; RCs, n=4), and soy (soymorphins; SMs, n=1) were behaviorally active in various paradigms assessing nociception, spontaneous behavior, and memory. Surprisingly, only a single study evaluating a gluten-derived peptide (gliadorphin-7; GD-7, n=1) was identified and included in this review. In conclusion, food-derived peptides can affect rodent behavior, but more studies of GDs using diverse behavioral batteries are warranted. Assuming they occur in sufficient quantities during protein digestion and can access central opioid receptors (which entails crossing both the gastrointestinal and blood-brain barriers intact), these peptides may affect human behavior. Although BCMs and GDs may not be directly pathogenic in SZ, documented associations of casein and gluten sensitivity with SZ justify increased patient screening and dietary intervention where necessary.

Nutritional interventions for the adjunctive treatment of schizophrenia: a brief review

Schizophrenia is a chronic condition that impacts significantly not only on the individual and family, but the disorder also has wider consequences for society in terms of significant costs to the economy. This highly prevalent condition affects approximately 1% of the worldwide population, yet there are few therapeutic options. The predominant treatment strategy for schizophrenia is anti-psychotic medication (with or without additional talking therapy) even though this approach lacks efficacy in managing the negative symptoms of the condition, is not effective in one-third of the patient group and the side effects of the medication can be severe and debilitating. In recent years, a number of pathophysiological processes have been identified in groups of people with schizophrenia including oxidative stress, one-carbon metabolism and immune-mediated responses. A number of studies have shown that these altered physiological mechanisms can be ameliorated by nutritional interventions in some individuals with schizophrenia. This review briefly describes the aforementioned processes and outlines research that has investigated the utility of nutritional approaches as an adjunct to anti-psychotic medication including antioxidant and vitamin B supplementation, neuroprotective and anti-inflammatory nutrients and exclusion diets. Whilst none of these interventions provides a ‘one-size-fits-all’ therapeutic solution, we suggest that a personalised approach warrants research attention as there is growing agreement that schizophrenia is a spectrum disorder that develops from the interplay between environmental and genetic factors.

Non-Celiac Gluten sensitivity: the new frontier of gluten related disorders

Non Celiac Gluten sensitivity (NCGS) was originally described in the 1980s and recently a "re-discovered" disorder characterized by intestinal and extra-intestinal symptoms related to the ingestion of gluten-containing food, in subjects that are not affected with either celiac disease (CD) or wheat allergy (WA). Although NCGS frequency is still unclear, epidemiological data have been generated that can help establishing the magnitude of the problem. Clinical studies further defined the identity of NCGS and its implications in human disease. An overlap between the irritable bowel syndrome (IBS) and NCGS has been detected, requiring even more stringent diagnostic criteria. Several studies suggested a relationship between NCGS and neuropsychiatric disorders, particularly autism and schizophrenia. The first case reports of NCGS in children have been described. Lack of biomarkers is still a major limitation of clinical studies, making it difficult to differentiate NCGS from other gluten related disorders. Recent studies raised the possibility that, beside gluten, wheat amylase-trypsin inhibitors and low-fermentable, poorly-absorbed, short-chain carbohydrates can contribute to symptoms (at least those related to IBS) experienced by NCGS patients. In this paper we report the major advances and current trends on NCGS.

Neurologic and psychiatric manifestations of celiac disease and gluten sensitivity

Celiac Disease (CD) is an immune-mediated disease dependent on gluten (a protein present in wheat, rye or barley) that occurs in about 1% of the population and is generally characterized by gastrointestinal complaints. More recently the understanding and knowledge of gluten sensitivity (GS), has emerged as an illness distinct from celiac disease with an estimated prevalence 6 times that of CD. Gluten sensitive people do not have villous atrophy or antibodies that are present in celiac disease, but rather they can test positive for antibodies to gliadin. Both CD and GS may present with a variety of neurologic and psychiatric co-morbidities, however, extraintestinal symptoms may be the prime presentation in those with GS. However, gluten sensitivity remains undertreated and underrecognized as a contributing factor to psychiatric and neurologic manifestations. This review focuses on neurologic and psychiatric manifestations implicated with gluten sensitivity, reviews the emergence of gluten sensitivity distinct from celiac disease, and summarizes the potential mechanisms related to this immune reaction.

Association between bovine casein antibody and new onset schizophrenia among US military personnel

Schizophrenia is a pervasive neuropsychiatric disorder of uncertain etiology. Multiple studies have documented immune activation in individuals with schizophrenia. One antigen capable of inducing a prolonged immune response is bovine casein derived from ingested milk products. Increased levels of casein antibodies have been found in individuals with schizophrenia after diagnosis. This study was directed at determining the potential association between schizophrenia and pre-illness onset levels of immunoglobulin G (IgG) antibodies to bovine casein. Parallel analyses for casein antibody levels with bipolar disorder were included as comparison. Cases were service members who received medical discharges from the military with a schizophrenia diagnosis from 1992 to 2005. Serum specimens were selected for 855 cases and 1165 matched healthy controls. IgG antibodies to bovine whole-casein were measured by solid phase enzyme-linked immunosorbent assays (ELISAs). Hazard ratios (HR) were calculated to examine the associations of casein IgG level with risk of schizophrenia by time to diagnosis and by subjects' initial level. Increasing casein IgG antibody levels among those with a high initial level, drawn before diagnosis, was associated with an 18% increase in the hazard risk of schizophrenia per unit increase (value of low-positive standard) in IgG antibody levels (HR=1.18; 95% CI 1.04, 1.34). This is the first report to identify an association between the risk of schizophrenia and elevated antibodies to bovine casein prior to disease onset. Additional research is required to elucidate the complex genetic environmental interactions involved in the pathogenesis of schizophrenia and to identify potentially modifiable risk factors.

The gluten connection: the association between schizophrenia and celiac disease

OBJECTIVE

Schizophrenia affects roughly 1% of the population and is considered one of the top 10 causes of disability worldwide. Given the immense cost to society, successful treatment options are imperative. Based on initial findings, gluten withdrawal may serve as a safe and economical alternative for the reduction of symptoms in a subset of patients.

METHOD

A review of the literature relevant to the association between schizophrenia and celiac disease (gluten intolerance) was conducted.

RESULTS

A drastic reduction, if not full remission, of schizophrenic symptoms after initiation of gluten withdrawal has been noted in a variety of studies. However, this occurs only in a subset of schizophrenic patients.

CONCLUSION

Large-scale epidemiological studies and clinical trials are needed to confirm the association between gluten and schizophrenia, and address the underlying mechanisms by which this association occurs.

Gene, gut and schizophrenia: the meeting point for the gene-environment interaction in developing schizophrenia

Both schizophrenia and celiac disease involve a genetic component. Several lines of evidence have shown a genetic relationship between these two conditions. Celiac disease is characterized by damage to the microscopic finger-like projections called villi, which line the small intestine and play a significant role in digestion, due to an inflammatory condition caused by a reaction to wheat gluten or related rye and barley proteins. Celiac disease represents not only malabsorption leading to a poor nutritional condition but also an alteration of gut permeability. Individuals with a history of a childhood celiac condition have a raised risk of developing schizophrenia. Psychotic symptoms often occur in adult celiac disease. It can be hypothesized that apart from malnutrition, the meeting point for the gene-environment interaction may be an alteration in gut permeability, in which the gut may lose its capacity to block exogenous psychosis-causing substances that may enter the body thus causing the development of schizophrenia and other mental conditions. To support this hypothesis, the conditional test was conducted to look at the combined effect of the CLDN5 gene involved in forming permeability barriers and the DQB1 gene that has been found to be associated with celiac disease. The results demonstrate that these two genes possibly work together in conferring a susceptibility to schizophrenia.

Could schizophrenia be reasonably explained by Dohan's hypothesis on genetic interaction with a dietary peptide overload?

1. Dohan has proposed that schizophrenia is a genetic disposition which interacts with an overload of dietary proteins such as casein and gluten or gliadin. 2. A systematic attempt is made to see if this hypothesis is possible faced with aspects of schizophrenia that must be accounted for. 3. The authors conclusion is that it is possible, but more serious work in this field is urgently needed.

Is schizophrenia caused by excessive production of interleukin-2 and interleukin-2 receptors by gastrointestinal lymphocytes?

Excessive production of interleukin-2 (IL-2) and IL-2 receptors (IL-2R) by gastrointestinal (GI) T-lymphocytes is hypothesized as the cause of schizophrenia. It is based on: 1) IL-2 given to human volunteers can cause all the symptoms of schizophrenia; 2) GI lymphocytes in nonhuman primates produce much more IL-2 and IL-2R when stimulated than peripheral blood lymphocytes; 3) the GI tract is the largest lymphoid 'organ' in the body. The hypothesis appears to: 1) explain the protective effect of rheumatoid arthritis on schizophrenia; 2) make mechanistically plausible the findings on wheat and schizophrenia; 3) be consistent with and explain many of the known immunological abnormalities in schizophrenia.

Small intestine permeability in schizophrenia

Gastrointestinal permeability was assessed by means of absorption of 51Cr-labelled EDTA in 24 patients with schizophrenia (12 in relapse and 12 in remission). The results were compared with those for patients with coeliac disease and those for normal controls. Significant differences between the schizophrenic patients and the normal controls were not established. The results for the schizophrenic patients in remission were no different from those for the patients in relapse, and there was no evidence from the study of an effect on gastrointestinal permeability of either anticholinergic or antidepressant medication. It is concluded that schizophrenia is, at least in the majority of cases, unrelated to coeliac disease.

A double-blind gluten-free/gluten-load controlled trial in a secure ward population

A double-blind control trial of gluten-free versus a gluten-containing diet was carried out in a ward of maximum security hospital: 24 patients were studied for 14 weeks. Most suffered from psychotic disorders, particularly schizophrenia. Various dimensions of behaviour were rated on the Psychotic In-Patient profile (PIP) at different stages. There were beneficial changes in the whole group of patients between pre-trial and gluten-free period in five dimensions of the PIP, maintained during the gluten challenge period; these changes could be attributed to the attention the patients received. Two patients improved during the gluten-free period and relapsed when the gluten diet was reintroduced.

Psychological and behavioral effects of food and chemical exposure in sensitive individuals

Dietary influences on behavior are of increasing scientific interest. In some cases, the effects appear limited to sensitive individuals. Thus, research on the role of wheat gluten in schizophrenia has produced conflicting results, but not all schizophrenics respond to wheat. Therefore, differences in statistical power may be a factor in these discrepant findings. Similarly, only a subset of hyperactive children seem to be affected by food colors. Another dietary influence on behavior may be sucrose consumption which was found to be directly correlated with behavior in children. In addition, the possible relationship of allergy to behavior is reviewed. Double-blind findings of the production of cognitive-emotional symptoms by sublingual provocative food and chemical challenges are described, with treatment follow-up data. Finally, a methodological note on provocative testing is included.