Association of ADHD and Celiac Disease: What Is the Evidence? A Systematic Review of the Literature

Celiac disease in children and adolescents with Down syndrome: behavioural, adaptive and sleep profiles

BACKGROUND

Individuals with Down syndrome (DS) exhibit higher risk for celiac disease (CD) than general population. Although literature suggests CD could be associated with behavioural problems in both paediatric and adult age, such association has been poorly explored in children and adolescents DS. Therefore, the current study aimed to investigate differences in emotional/behavioural difficulties, adaptive skills and sleep problems between children with DS with and without CD.

METHODS

Data were retrospectively collected from a database including data from 381 individuals with DS (3-18 years). The final sample included 65 participants, 27 with co-occurring CD and 38 age, IQ, sex and body mass index-matched controls without CD. Emotional/behavioural difficulties, adaptive skills and sleep problems were assessed through parent report questionnaires.

RESULTS

No group differences emerged in emotional/behavioural difficulties, whereas participants in the CD group showed better adaptive skills in the practical domain than control group. Weak differences emerged in sleep problems.

CONCLUSIONS

Youth with DS and co-occurring CD do not exhibit more emotional and behavioural problems than youth with DS without co-occurring CD but exhibit better adaptive skills in the practical domain.

The impacts associated with having ADHD: an umbrella review

Introduction

Attention Deficit Hyperactivity Disorder (ADHD) affects up to 5% of the population and is characterised by symptoms of impulsivity, hyperactivity and inattention. These symptoms are significantly impairing and carry additional risks for children and adults with ADHD, including negative mental health (e.g. depression), physical health (e.g. obesity) and societal outcomes (e.g. imprisonment, divorce). Very few studies have attempted to synthesise these risks in one publication due to the breadth of evidence published on the adverse outcomes of ADHD.

Methods

An umbrella review was performed to identify reviews (systematic, meta-analysis and narrative) that investigate the risks arising from having ADHD. We conducted a narrative synthesis of the findings and conducted a quality review of the included publications.

Results

Upon searching five databases, 16,675 records were identified. Of these, 125 reviews met the criteria for inclusion. A narrative synthesis of these findings highlighted three key domains of risks associated with ADHD: mental health, physical health, social and lifestyle. Most reviews were of good and moderate quality.

Discussion

This review highlights the many risks associated with having ADHD, beyond its three key symptom domains and the impact of the condition on daily functioning.

Registration

International Prospective Register of Systematic Reviews (PROSPERO CRD42023404073).

Genetic and environmental contributions to co-occurring physical health conditions in autism spectrum condition and attention-deficit/hyperactivity disorder

BACKGROUND

Autism spectrum condition and attention-deficit/hyperactivity disorder (ADHD) are associated with a range of physical health conditions. The aim of this study was to examine the etiological components contributing to co-occurring physical health conditions in autism and ADHD.

METHODS

In this nationwide Child and Adolescent Twin Study in Sweden, we analyzed data from 10,347 twin pairs aged 9 and 12. Clinical diagnoses of autism, ADHD, and physical health conditions were identified through the Swedish National Patient Register. Subclinical phenotypes of autism and ADHD were defined by symptom thresholds on a standardized parent-interview, the Autism-Tics, ADHD, and Other Comorbidities inventory. Associations between physical health conditions and autism/ADHD phenotypes were examined using generalized estimating equations. Bivariate twin models were applied to estimate the extent to which genetic and environmental risk factors accounted for physical health comorbidities.

RESULTS

Similar patterns of association with physical health conditions were found in clinical and subclinical autism/ADHD, with odds ratios ranging from 1.31 for asthma in subclinical ADHD to 8.03 for epilepsy in clinical autism. The estimated genetic correlation (r_a) with epilepsy was 0.50 for clinical autism and 0.35 for subclinical autism. In addition, a modest genetic correlation was estimated between clinical autism and constipation (r_a = 0.31), functional diarrhea (r_a = 0.27) as well as mixed gastrointestinal disorders (r_a = 0.30). Genetic effects contributed 0.86 for mixed gastrointestinal disorders in clinical ADHD (r_a = 0.21). Finally, subclinical ADHD shared genetic risk factors with epilepsy, constipation, and mixed gastrointestinal disorders (r_a = 0.30, 0.17, and 0.17, respectively).

LIMITATIONS

Importantly, since medical records from primary care were not included in the registry data used, we probably identified only more severe rather than the full range of physical health conditions. Furthermore, it needs to be considered that the higher prevalence of physical health conditions among autistic children and children with ADHD could be associated with the increased number of medical visits.

CONCLUSIONS

Shared genetic effects contribute significantly to autism and ADHD phenotypes with the co-occurring physical health conditions across different organ systems, including epilepsy and gastrointestinal disorders. The shared genetic liability with co-occurring physical health conditions was present across different levels of autism and ADHD symptom severity.

A Clinical Investigation on ADHD-Traits in Childhood Celiac Disease

OBJECTIVE

There are no definitive results about either the presence of exact comorbidity between celiac disease (CD) and attention-deficit/hyperactivity disorders (ADHD) or etiology. We intend to screen ADHD-related cognitive and behavioral traits in children with biopsy-proven CD and investigate the possible association of these traits with certain vitamin levels, body-mass index, and gluten-free diet (GFD) compliance.

METHOD

A total of 85 children with biopsy-proven CD (the ages of 8-18 years) were compared with age and sex-matched 72 healthy controls in terms of demographics, psychiatric symptoms, certain vitamin levels, and anthropometric measurements.

RESULTS

ADHD-like cognitive issues, such as inattention and learning difficulties, as well as psychosomatic symptoms and poor prosocial behavior, were all associated with GFD noncompliance in childhood CD.

CONCLUSION

Untreated CD may predispose to ADHD-resembling symptoms. Physicians should be aware of the probability of ADHD misdiagnosing due to ADHD-resembling cognitive and behavioral traits in untreated CD.

The Association between ADHD and Celiac Disease in Children

Controversy around the association between celiac disease (CeD) and attention deficit hyperactive disorder (ADHD) was addressed by a systematic review in 2015, ultimately showing no association. Since 2015, there have been several studies showing an association between celiac disease and attention deficit hyperactive disorder. This is an updated systematic review. Background: Most experts agree on the recommendation to not screen as part of the standard of care for ADHD in persons with CeD or vice versa. Simultaneously, they propose that untreated patients with CeD and neurological symptoms such as chronic fatigue, inattention, pain, and headache could be predisposed to ADHD-like behavior, namely inattention (which may be alleviated by following a gluten-free diet). The inattentive subtype of ADHD that encompasses the symptoms of inattention is phenotypically heterogeneous, as it includes the clinical construct of sluggish cognitive tempo (SCT). SCT symptoms overlap with the neurological manifestations of CeD. Methods: A systematic search (PRISMA) of PubMed, Google Scholar, EMBASE, Web of Science, Stanford Lane, SCOPUS, and Ovid was conducted for articles up to 21 February 2022. Of these, 23 studies met the criteria. Results: Out of the 23 studies, 13 showed a positive association between ADHD and CeD. Most studies that showed a positive association had been published in the last five years. Inconsistencies in the results remain due to the heterogeneous methodology used, specifically for ADHD and the outcome questionnaires, as well as a lack of reporting on ADHD subtypes. Conclusion: There is an association between ADHD and celiac disease. The current methodological limitations will be lessened if we examine the subtypes of ADHD.

Is attention-deficit hyperactivity disorder increased in patients with celiac disease?

Background

Some studies have shown that neurological and mental disorders in children with celiac disease are higher than in the general population. The aim of this study is to find frequency of ADHD in celiac patients.

Result

The findings of the study showed that the frequency of ADHD in males was 6 cases (22.2%) and 6 cases (18.2%) in females, and although the ADHD score was higher in males, there was no significant difference in sex (P = 0.697). The frequency of ADHD in terms of age group also showed that there were no hyperactive children in the age group under 5 years of age; in the age group of 5–9 years old, 8 cases (28.6%); in the age group of 10 to 14 years old, 4 cases (19%); and in the age group of 15 and older, no one was diagnosed with ADHD. The chi-square test showed that the frequency of ADHD in terms of age group was not significantly different (P = 0.26). It should be noted that according to Pearson correlation test, there was a reverse correlation between the age and ADHD, but it was not statistically significant (P = 0.33).

Conclusions

The frequency of ADHD among boys and girls with celiac disease was 22.2% and 18.2%, respectively.

Association of Food Allergy, Respiratory Allergy, and Skin Allergy with Attention Deficit/Hyperactivity Disorder among Children

BACKGROUND

Previous studies have predominately examined associations of respiratory allergy and skin allergy with ADHD, but little is known about the association between food allergy and ADHD.

METHODS

We included 192,573 children aged 4-17 years from the National Health Interview Survey (NHIS), a leading health survey in a nationally representative sample of the US population. Allergy conditions and ADHD were defined based on an affirmative response in the NHIS questionnaire. We used weighted logistic regression to estimate the odds ratio (OR) of ADHD.

RESULTS

Among the 192,573 children, 15,376 reported ADHD diagnosis. The prevalence of ADHD was higher among children with allergic conditions: 12.66% vs. 7.99% among children with and without food allergy; 12.16% vs. 7.63% among children with and without respiratory allergy; and 11.46% vs. 7.83% among children with and without skin allergy. After adjusting for covariates, the OR of ADHD was 1.72 (95% CI, 1.55-1.91) comparing children with and without food allergy, 1.50 (95% CI, 1.41-1.59) comparing children with and without respiratory allergy, and 1.65 (95% CI, 1.55-1.75) comparing children with and without skin allergy. The observed associations remained significant after mutual adjustment for other allergic conditions.

CONCLUSIONS

In a nationally representative sample of US children, we found a significant association of common allergic conditions (food allergy, respiratory allergy, and skin allergy) with ADHD.

Non-mental diseases associated with ADHD across the lifespan: Fidgety Philipp and Pippi Longstocking at risk of multimorbidity?

Several non-mental diseases seem to be associated with an increased risk of ADHD and ADHD seems to be associated with increased risk for non-mental diseases. The underlying trajectories leading to such brain-body co-occurrences are often unclear - are there direct causal relationships from one disorder to the other, or does the sharing of genetic and/or environmental risk factors lead to their occurring together more frequently or both? Our goal with this narrative review was to provide a conceptual synthesis of the associations between ADHD and non-mental disease across the lifespan. We discuss potential shared pathologic mechanisms, genetic background and treatments in co-occurring diseases. For those co-occurrences for which published studies with sufficient sample sizes exist, meta-analyses have been published by others and we discuss those in detail. We conclude that non-mental diseases are common in ADHD and vice versa and add to the disease burden of the patient across the lifespan. Insufficient attention to such co-occurring conditions may result in missed diagnoses and suboptimal treatment in the affected individuals.

Epidemiology and risk of psychiatric disorders among patients with celiac disease: A population-based national study

BACKGROUND AND AIM

Celiac disease (CD) is a chronic disorder resulting from an immune reaction to gluten in genetically predisposed individuals. Although several studies have linked CD to psychiatric diseases, there are limited data on this topic. Using a large database, we sought to describe the epidemiology of several psychiatric disorders in CD.

METHODS

We queried a multicenter database (Explorys Inc), an aggregate of electronic health record data from 26 major integrated healthcare systems from 2016 to 2020 consisting of 360 hospitals in the USA. A cohort of patients with a Systematized Nomenclature Of Medicine - Clinical Terms diagnosis of CD was identified. Multivariate analysis was performed using Statistical Package for Social Sciences version 25.

RESULTS

Of the 37 465 810 patients in the database between 2016 and 2020, there were 112 340 (0.30%) individuals with CD. When compared with patients with no history of CD, patients with CD were more likely to have a history of anxiety (odds ratio [OR]: 1.385; 95% confidence interval [CI]: 1.364-1.407), depression (OR: 1.918; 95% CI: 1.888-1.947), bipolar (OR: 1.321; 95% CI: 1.289-1.354), attention-deficit hyperactivity disorder (OR: 1.753; 95% CI: 1.714-1.792), eating disorder (OR: 15.84; 95% CI: 15.533-16.154), and childhood autistic disorder (OR: 4.858; 95% CI: 3.626-6.508). Patients with CD and psychiatric conditions were more likely to be smokers, with history of alcohol and substance abuse as well as a history of personality disorder.

CONCLUSIONS

In this large database, patients with CD are at increased risk of having multiple psychiatric diseases including anxiety, depression, bipolar, attention-deficit hyperactivity disorder, eating disorder, and childhood autism. Individual care and referral to psychiatry when appropriate are warranted while taking care of this group of patients.

Conduct disorder and somatic health in children: a nationwide genetically sensitive study

BACKGROUND

Conduct disorder (CD), a serious behavioral and emotional disorder in childhood and adolescence, characterized by disruptive behavior and breaking societal rules. Studies have explored the overlap of CD with neurodevelopmental problems (NDP). The somatic health of children with NDP has been investigated; however, the prevalence of these problems in children with CD has not been sufficiently studied. Holistic assessment of children with CD is required for establishing effective treatment strategies.

AIMS

(1) Define the prevalence of selected neurological problems (migraine and epilepsy) and gastrointestinal problems (celiac disease, lactose intolerance, diarrhea, and constipation) in a population of twins aged 9 or 12; (2) Compare the prevalence of somatic problems in three subpopulations: (a) children without CD or NDP, (b) children with CD, and (c) children with both CD and NDP; (3) Select twin pairs where at least one child screened positive for CD but not NDP (proband) and map both children's neurological and gastrointestinal problems.

METHOD

Telephone interviews with parents of 20,302 twins in a cross-sectional, nationwide, ongoing study. According to their scores on the Autism-Tics, AD/HD, and Comorbidities inventory, screen-positive children were selected and divided into two groups: (1) children with CD Only, (2) children with CD and at least one NDP.

RESULTS

Children with CD had an increased prevalence of each neurological and gastrointestinal problem (except celiac disease), and the prevalence of somatic problems was further increased among children with comorbid CD and NDP. The presence of CD (without NDP) increased the odds of constipation for girls and the odds of epilepsy for boys. Girls with CD generally had more coexisting gastrointestinal problems than boys with CD. Female co-twins of probands with CD were strongly affected by gastrointestinal problems. Concordance analyses suggested genetic background factors in neurological and gastrointestinal problems, but no common etiology with CD could be concluded.

CONCLUSION

Co-occurring NDP could explain most of the increased prevalence of somatic problems in CD. Our results raise a new perspective on CD in children and adolescents; their CD seems to be linked to a number of other health problems, ranging from neurodevelopmental and psychiatric disorders to somatic complaints.

Attention deficit hyperactivity disorder and gastrointestinal morbidity in a large cohort of young adults

BACKGROUND

Although the association of attention deficit hyperactivity disorder (ADHD) with psychiatric disorders is well known, its association with somatic diseases is unclear. Only few studies have investigated the gastrointestinal (GI) morbidity in adult patients with ADHD.

AIM

To measure gastrointestinal comorbidity and its burden on healthcare in young adults with ADHD.

METHODS

The cohort included subjects aged 17-35 years recruited to the Israel Defense Forces in 2007-2013, 33380 with ADHD and 355652 without (controls). The groups were compared for functional and inflammatory conditions of the gastrointestinal tract and clinic and specialist visits for gastrointestinal symptoms/disease during service (to 2016). Findings were analyzed by generalized linear models adjusted for background variables.

RESULTS

Compared to controls, the ADHD group had more diagnoses of functional gastrointestinal disorders (referred to as FGID), namely, dyspepsia [odds ratio (OR): 1.48, 95% confidence interval (CI): 1.40-1.57, P < 0.001], chronic constipation (OR: 1.64, 95%CI: 1.48-1.81, P < 0.001), and irritable bowel syndrome (OR: 1.67, 95%CI: 1.56-1.80, P < 0.001) but not of organic disorders (inflammatory bowel disease, celiac disease). They had more frequent primary care visits for gastrointestinal symptoms [rate ratio (RR): 1.25, 95%CI: 1.24-1.26, P < 0.001] and referrals to gastrointestinal specialists (RR: 1.96, 95%CI: 1.88-2.03, P < 0.001) and more episodes of recurrent gastrointestinal symptoms (RR: 1.29, 95%CI: 1.21-1.38, P < 0.001). Methylphenidate use increased the risk of dyspepsia (OR: 1.49, 95%CI: 1.28-1.73, P < 0.001) and constipation (OR: 1.42, 95%CI: 1.09-1.84, P = 0.009).

CONCLUSION

ADHD in young adults is associated with an excess of FGID and increased use of related health services. Research is needed to determine if an integrative approach treating both conditions will benefit these patients and cut costs.

Prevalence of Celiac Disease Is Not Increased in ADHD Sample

Objective: The purpose of the present study was to examine the prevalence of celiac disease (CD) in children and adolescents with ADHD. Method: In all, 102 participants between 4 and 18 years of age diagnosed with ADHD participated in the study (M = 12.8 years; 84 boys and 18 girls). CD was diagnosed according to the adapted guidelines of the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPHGAN). Results: Among 102 tested children and teenagers with ADHD, we did not find anyone with suspected CD, so further diagnostic procedures for CD were not indicated. Conclusion: In our sample of children and teenagers with ADHD, the prevalence of CD was not higher than in the general population. On the basis of the obtained results and the results of similar studies, we conclude that there are not enough data to support screening for CD and the introduction of a gluten-free diet in children with ADHD unless there are additional indications.

Attention deficit and hyperactivity disorder symptoms respond to gluten-free diet in patients with coeliac disease

Introduction: Patients with coeliac disease commonly report symptoms of 'brain fog'. The aim of this study was to assess self-reported symptoms of impaired concentration in coeliac disease before and after treatment with gluten-free diet, compared with healthy controls and patient controls. Methods: Patients with newly diagnosed coeliac disease were included consecutively from two out-patient clinics. The patients completed the questionnaires Adult ADHD Self-Report Scale v1.1 Symptoms Checklist (ASRS), Hospital Anxiety and Depression Scale (HADS) and Gastrointestinal Symptom Rating Scale (GSRS) prior to start of a gluten-free diet and after at least 12 months on the diet. Patients with an established diagnosis of inflammatory bowel disease served as patient controls (n = 36). Health care personnel at Oslo University Hospital served as healthy controls (n = 60) and filled out ASRS and HADS. Results: A total of 31 newly diagnosed coeliac patients were included in the study. Of these, 26 patients met for follow-up and repeated the questionnaires. Prior to treatment, patients with coeliac disease had significantly higher scores than healthy controls on both the ASRS (p = .0014) and HADS (p=.0004). After a gluten-free diet, their scores improved and were not significantly different from healthy controls. There were no significant differences between patients with coeliac disease prior to treatment and patient controls with inflammatory bowel disease. Conclusion: Prior to treatment, coeliac disease patients reported significantly more symptoms than healthy controls on ASRS and HADS. The differences disappeared after a minimum of 12 months on a gluten-free diet.

Coeliac disease in children: the need to improve awareness in resource-limited settings

Coeliac disease (CD) is an immune-mediated systemic disorder caused by the ingestion of gluten. In children, it may present with intestinal or extra-intestinal manifestations such as diarrhoea, weight loss, iron deficiency anaemia or faltering growth. Diagnosis is confirmed by small bowel biopsies showing histological changes consistent with enteropathy. In 2012, the European Society for Paediatric Gastroenterology, Hepatology and Nutrition revised the CD guidelines and suggested that, in a selective group of symptomatic children, CD can be diagnosed without the need for small-bowel biopsies. Management of CD is through strict adherence to a life-long gluten-free diet (GFD). CD is of great public health significance as its prevalence in developing countries has been found to be similar to that in developed countries. Early recognition and treatment improves prognosis. Patients and families require long term support to enable effective adherence to a GFD lifestyle. This alone can be challenging, but through support of health professionals and dietitians, can improve patient outcomes. In resource-limited settings medical professionals need to be creative in formulating cheaper and locally sourced gluten free options in close cooperation with the dietitians thereby ensuring availability of gluten free food items at affordable prices. In this paper, we gave an overview of the subject followed by authors' view to emphasize the need for improved awareness in resource-limited settings.

Efficacy of a Gluten-Free Diet in the Gilles de la Tourette Syndrome: A Pilot Study

The Gilles de la Tourette syndrome (GTS) and Non-Coeliac Gluten Sensitivity (NCGS) may be associated. We analyse the efficacy of a gluten-free diet (GFD) in 29 patients with GTS (23 children; six adults) in a prospective pilot study. All of them followed a GFD for one year. The Yale Global Tics Severity Scale (YGTSS), the Yale-Brown Obsessive-Compulsive Scale—Self Report (Y-BOCS) or the Children’s Yale-Brown Obsessive-Compulsive Scale—Self Report (CY-BOCS), and the Cavanna’s Quality of Life Questionnaire applied to GTS (GTS-QOL) were compared before and after the GFD; 74% of children and 50% of adults were males, not significant (NS). At the beginning of the study, 69% of children and 100% of adults had associated obsessive-compulsive disorder (OCD) (NS). At baseline, the YGTSS scores were 55.0 ± 17.5 (children) and 55.8 ± 19.8 (adults) (NS), the Y-BOCS/CY-BOCS scores were 15.3, (standard deviation (SD) = 12.3) (children) and 26.8 (9.2) (adults) (p = 0.043), and the GTS-QOL scores were 42.8 ± 18.5 (children) and 64 ± 7.9 (adults) (p = 0.000). NCGS was frequent in both groups, with headaches reported by 47.0% of children and 83.6% of adults (p = 0.001). After one year on a GFD there was a marked reduction in measures of tics (YGTSS) (p = 0.001), and the intensity and frequency of OCD (Y-BOCS/CY-BOCS) (p = 0.001), along with improved generic quality of life (p = 0.001) in children and adults. In conclusion, a GFD maintained for one year in GTS patients led to a marked reduction in tics and OCD both in children and adults.

Coeliac disease and psychiatric comorbidity: epidemiology, pathophysiological mechanisms, quality-of-life, and gluten-free diet effects

Coeliac Disease (CD) is an autoimmune disease in which an environmental factor, gluten, triggers a pathological reaction. It results in intra- and entra-intestinal manifestations of disease, including, most frequently, diarrhoea, weight loss, and anaemia. CD occurs in ∼1% of the western population, being one of the most common autoimmune lifelong disorders, and may present with a variety of psychiatric comorbidities. Psychiatric comorbidity in CD often complicates the diagnosis, reduces the quality-of-life, and worsens the prognosis of affected patients. This review summarizes the epidemiological studies that underline this connection, and focuses on the potential mechanisms related to this comorbility, such as nutritional deficiencies, immune responses, interference in brain processes, and dysfunctions in the gut-brain axis. Factors that play a central role on patients' quality of life, psychological well-being and adherence are presented. Finally, evidence of regression in psychiatric symptoms following the introduction of a gluten-free diet is underlined as well.

Gluten Intolerance and Neurodevelopmental Disorders: Is Nitric Oxide the Common Biomarker Linking These Conditions?

Cruchet et al. attempt to tease out the myths and facts surrounding the growing popularity of certain dietary approaches in the management of neurodevelopmental disorders, like attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorders (ASDs). The authors identify a particular exclusionary-type approach that seeks to eliminate dietary gluten. Although the relationship between celiac disease (CD) and ADHD/ASD is not well established, a repeated clinical feature noted in CD is the elevated levels of nitric oxide in serum and urine. Elevated oxidative stress has also been observed in neurodevelopmental conditions, and the author of this correspondence has been the first to propose that chronic, environmental exposure to the air pollutant, nitrous oxide may contribute to these oxidative stress profiles through neural cholinergic perturbation. Therefore, the purpose of this correspondence is to highlight this biochemical connection between these conditions so as to identify the clinical populations who may realize the greatest benefit of these dietary approaches, while minimizing any potential risk of nutrient deficiencies.