Background: Celiac disease is an immune-mediated reaction to gluten, presenting with diarrhea, weight loss, abdominal complaints and a range of less common associated neurologic and psychiatric symptoms. Evidence of a link between schizophrenia and celiac disease dates back to 1961. Recent evidence shows that 5.5% (age adjusted) of persons with schizophrenia participating in the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) study had a level of antibodies to tTG that is consistent with a diagnosis of celiac disease (compared to 1.1% of the comparison sample). An unexpected finding was that 23.4% (age adjusted) of the CATIE sample had antibodies to gliadin (compared to 2.9% of the comparison sample). It is hypothesized that a gluten free diet in people with schizophrenia who have Celiac disease or gluten sensitivity will have improvement in symptoms and quality of life.

Objectives: The aim of this proposed pilot study is to establish the feasibility of a initiating and maintaining a Gluten-free diet in these two groups. For this study The investigators will identify 8 individuals who have positive assays to tTG antibodies and confirmed celiac disease (N=4), or positive assays for anti-gliadin antibodies (N=4). The investigators plan to consent at least 2 subjects from each group and ask them to participate in a two-week open label treatment of a gluten free diet. The groups are;

1. Celiac disease (positive tTG antibody); and
2. Positive assay on Antigliadin antibodies

Inclusion Criteria:

• Subjects will be of either gender and of any race, with an age range of 18 55.
• Subjects will meet DSM-IV (APA, 1994) criteria for either schizophrenia or schizoaffective disorder. A best estimate diagnostic approach will be utilized in which information from the Structured Clinical Interview for DSM-IV (First et al, 1997) is supplemented by information from family informants, previous psychiatrists, and medical records to generate a diagnosis.
• Subjects will be required to have celiac disease (positive tTG antibody) or have gluten sensitivity (positive or AGA antibodies).
• Must be clinically stable and on the same antipsychotic for at least two months with an unchanged dose for the prior four weeks.
• Participants must complete the Evaluation to Sign Consent with a score of 10/12 or higher.

Exclusion Criteria:

• Pregnant or lactating women will be excluded. Pregnancy will be determined by pregnancy test. Lactating will be determined by participant report.