RESUMEN
Background: Mood disorders are common in Graves' disease despite treatment. The pathogenic mechanisms involved are unknown and so is whether previous psychiatric disease influences these symptoms. Methods: This is a longitudinal study conducted in Sweden on 65 women with newly diagnosed Graves' disease and 65 matched controls. Participants were examined during hyperthyroidism and after 15 months of treatment. Examinations included blood sampling, and psychiatric testing with the Comprehensive Psychopathological Rating Scale for Affective Syndromes and the Structured Clinical Interview for DSM-IV - Axis I Disorders. We also performed two analyses of a national population-based registry to determine previous psychiatric diagnoses and previous prescriptions of psychoactive drugs in (i) all patients we asked to participate and (ii) all Swedish women given a diagnosis of hyperthyroidism during 2013-2018, comparing them to matched controls. Results: There was no increased previous psychiatric comorbidity in Graves' patients compared to controls. There was no higher prevalence of psychiatric diagnoses and prescriptions of psychoactive drugs between (i) included GD patients compared to those who declined participation and (ii) women with a hyperthyroidism diagnosis in 5 years prior to their diagnosis, compared to matched controls. Depression scores and anxiety scores were higher in patients compared to controls both during hyperthyroidism (depression (median (IQR): 7.5 (5.0-9.5) vs 1.0 (0.5-2.5) P < 0.001), anxiety: 7.7 (5.0-11) vs 2.5 (1.0-4.0) P < 0.001) and after treatment (depression: 2.5 (1.5-5.0) vs 1.5 (0.5-3.5) P < 0.05), anxiety: 4.0 (2.5-7.5) vs 3.0 (1.5-5.0) P < 0.05). Patients with a previous psychiatric condition, mild eye symptoms, and a younger age had more anxiety at 15 months compared to patients without these symptoms and a higher age (all p<0.05). Conclusion: Graves' disease affects patients' mood despite treatment. A previous psychiatric condition, mild eye symptoms, and a younger age increase the vulnerability for long-lasting symptoms and require specific attention.