PURPOSE: to study the association between hypothyroidism and depression and anxiety symptoms. METHODS: a case-control study was carried out from July 2006 to March 2008 on 100 patients (50 patients with primary hypothyroidism and 50 euthyroid controls) aged 18 to 65 years. Age, race/skin color, marital status, education level, alcohol use, working status, body mass index and menopausal status were evaluated. TSH levels were determined and the Beck Depression and Beck Anxiety Scales were applied to all cases and controls. Statistical analysis was performed using the SPSS software version 14.0. The level of significance was set at p<0.05. RESULTS: there was no demographic or epidemiologic difference between groups. The concomitant presence of anxiety and depression was five times greater among cases than among controls (20.0 versus 4.0%, p=0.01). Anxiety symptoms were approximately three times more frequent among cases (40.0%) than among controls (14.0%) (p=0.003), while the prevalence of depressive symptoms was 75% higher among cases (28.0%) than among controls (16.0%), but this did not reach statistical significance (p=0.15). We found no association between TSH levels and the prevalence of anxiety or depression symptoms. CONCLUSIONS: this case-control study showed a greater probability for hypothyroid patients to develop anxiety and depression symptoms when compared to euthyroid controls. Due to the high prevalence of hypothyroidism and depression observed in clinical practice, depressive symptoms must be considered in patients with thyroid dysfunction and depressed patients should be tested for TSH.
Depression; Anxiety; Hypothyroidism
