Science

Helmut Niederhofer, MD, PhD

Objective: A possible association of celiac disease with psychiatric and psychological disturbances such as attention-deficit/hyperactivity disorder (ADHD) has been reported repeatedly. The objective of this study was to observe whether a gluten-free diet could alleviate the behavioral symptoms in patients with celiac disease and ADHD.
Method: Sixty-seven subjects aged 7 to 42 years (mean = 11.4 years) with ADHD were enrolled in the study in South Tyrol, Italy, from 2004 to 2008. Hypescheme, an operational criteria checklist that incorporates DSM-IV and ICD-10 criteria, was used to assess ADHD-like symptomatology. Additionally, blood serum levels of all subjects were assessed for possible celiac disease by examining antigliadine and antiendomysium antibodies. A gluten-free diet was initiated for at least 6 months in celiac disease–positive patients with ADHD.
Results: Of the 67 patients with ADHD, 10 were positive for celiac disease. After initiation of the gluten-free diet, patients or their parents reported a significant improvement in their behavior and functioning compared to the period before celiac diagnosis and treatment, which was evident in the overall mean score on the Hypescheme questionnaire (t = 4.22, P = .023).
Conclusions: Celiac disease is markedly overrepresented among patients presenting with ADHD. A gluten-free diet significantly improved ADHD symptoms in patients with celiac disease in this study. The results further suggest that celiac disease should be included in the ADHD symptom checklist.
The diagnosis of celiac disease, a destructive inflammatory disease of the mucosa of the upper small intestine resulting from gluten ingestion in genetically susceptible individuals, is based on demonstration of a more or less pronounced villus atrophy in a jejunal biopsy. Therapy for celiac disease consists of permanently excluding gluten from the diet and allows for total healing of the mucosal lesion.
Since the early 1980s, it has become evident that celiac disease is underdiagnosed. In young Italians aged 6–15 years, the overall prevalence of celiac disease was 1 in 184, as screened by combined determination of serum immunoglobulin G (IgG) and IgA antigliadine antibody test. Among healthy Finnish adults, the prevalence was as high as 1 in 130 using IgA antiendomysium antibody determination. Presentation with minor symptoms, such as irritable bowel syndrome, anemia, slight weight loss, and fatigue, has become increasingly common, and, in many cases, the disease may be clinically silent despite manifest small bowel mucosal lesions. If undetected or neglected, celiac disease may cause considerable late complications from malabsorption or secondary autoimmune diseases.
Psychiatric symptoms as well as neurologic dysfunctions are common in patients with celiac disease. Depressive symptoms are often present in adults with the disease, regardless of treatment and age at diagnosis. In some cases, depressive symptoms have reportedly improved soon after starting a gluten-free diet. The prevalence of severe mental and behavioral disorders in untreated celiac disease is unknown, but a history of psychiatric treatment before the diagnosis of celiac disease has been reported in 21% (9/42) of adult patients with the disease compared with 5% (2/42) of a medical control group. The objective of this study was to observe whether a gluten-free diet could alleviate those behavioral symptoms.