OBJECTIVE: To evaluate the association between celiac disease and specific anxiety and depressive disorders and to identify potential common pathogenetic links, with particular regard to thyroid function and autoimmunity. METHODS: Cases included 36 adult celiac patients, 25 females and 11 males, aged 18-64 years. Controls comprised 144 healthy subjects matched by sex and age with no clinical evidence or family history of celiac disease. Diagnosis of celiac disease was made on the basis of clinical history and serological criteria. Psychiatric diagnoses were formulated using the International Composite Diagnostic Interview, according to DSM-IV criteria. Thyroid was evaluated by palpation, echography and measurement of serum-free thyroid hormones (FT4, FT3), thyroid-stimulating hormone (TSH) and antithyroid autoantibodies (anti-TPO). RESULTS: Compared to controls, a significantly higher number of celiac patients met criteria for lifetime [15 (41.7%) versus 30 (29.8%), P < .01] and 6-month [7 (19.4%) versus 9 (6.2%), OR = 3.2, chi(2) = 5.2, P < .05] major depressive disorder (MDD) and lifetime [5 (13.9%) versus 3 (2.1%), P < .001] and 6-month [3 (8.1%) versus 2 (1.4%), P < .05] panic disorder (PD). Anti-TPO prevalence was significantly higher in celiac patients than in the control group (11/36 = 30.5% versus 14/144 = 9.7%, P < .001). A higher frequency of PD and MDD was found in celiac patients with positive anti-TPO when compared to negative anti-TPO patients (4/11 = 36.4% PD in TPO+ versus 1/25 = 4% PD in TPO-, P < .01; 9/11 = 81.8% MD in TPO+ versus 6/25 = 9.5% MD in TPO-, P < .01). CONCLUSION: Patients affected by celiac disease tend to show a high prevalence of PD and MDD and association with subclinical thyroid disease appears to represent a significant risk factor for these psychiatric disorders. Copyright 2002 Elsevier Science Inc.