The present is a cross-sectional, comparative study including case and control arms, with follow-up on the case arm, and compared the presence of various psychiatric disorders among people with hyperthyroidism, with and without treatment, and people without hyperthyroidism. The study was conducted between March 2017 and March 2019.
The study targeted people over 15 years of age with hyperthyroidism who attended the Endocrinology Outpatient Department at the Shri Maharaja Hari Singh Hospital in North India. Participants were selected using stratified random sampling, choosing every alternate female patient with hyperthyroidism. The control group was people over 15 years of age without any present or past thyroid disease and family history of thyroid disease. The case group also included hyperthyroid patients assessed after 2 months of treatment. Thyroid status was checked using a thyroid function test (TFT) that included an estimation of serum triiodothyronine (T3), tetra-iodothyronine (T4), and thyroid-stimulating hormone (TSH) and clinical profile of the patient were monitored to see the effect of endocrinological medications in the follow-up of hyperthyroid patients. Sampling of participants was conducted for a period of 6 months. The assessment of patients before and after treatment was done and those who did not improve were referred for psychiatric treatment. Exclusion criteria were the presence of pregnancy or a history of pregnancy in the last 6 months, and the use of steroids or other drugs known to interfere with thyroid function. The control group was taken from another Outpatient Department of the same hospital and was subjected to the same laboratory investigation for confirmation.
Data collection included demographic information, such as age, sex, residence, and economic status.
Endocrinologists evaluated all study and control subjects. This evaluation included a detailed haemogram, erythrocyte sedimentation rate (ESR), and serum biochemistry in the form of blood glucose, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, and cholesterol. All participants also had a thyroid function test (TFT) that included an estimation of serum triiodothyronine (T3), tetra-iodothyronine (T4), and thyroid-stimulating hormone (TSH). The diagnosis of hyperthyroidism was made based on clinical criteria and confirmed by the elevated serum T3 and/or T4 and suppressed TSH (< 0.1 IU/mL). Participants with laboratory confirmation of hyperthyroidism had done a technetium scan of the thyroid gland using 99mTc-pertechnate. Graves’ disease (GD) diagnosis was based on diffuse goitre with increased radioactive iodine uptake (RAIU) at 24 h.
Different treatments were given for different thyroid conditions with different diagnoses. Patients with hyperthyroidism were treated by surgery, antithyroid drug (ATD) medication, or radioactive iodine (RAI). Local traditions, severity of the disease, sex, and age are some of the factors that influenced the type of treatment chosen.
Mental status evaluation
The psychiatric history was taken using a pretested semi-structured interview. The interviewer was blind to the participants’ endocrinological diagnosis. These interviews were conducted using the mood and anxiety modules of the Mini-International Neuropsychiatric Interview (MINI)  and the diagnostic criteria for depression and anxiety of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition . In addition, all participants were evaluated using both observer-rated and self-rated scales. A psychiatrist applied Hamilton Depression Rating Scale (HAM-D) and Hamilton Anxiety Rating Scale (HAM-A) [12, 13].
Hormones of the hypothalamic–pituitary–thyroid axis
Venous blood was drawn for the measurement of serum thyrotropin (TSH), thyroxine (T4), and total T3 (TT3). All hormones were estimated by commercially available chemiluminescence assay (CLA); antithyroid peroxidase antibody (anti-TPO) was estimated by immunofluorescence technique (ELISA).
Data were keyed into Microsoft Excel 2016 and after cleaning exported to Statistical Package for the Social Science® (SPSS) for Mac ® version 25.0 software (SPSS Inc., IL, USA) for further analysis. Numbers and percentages were used to present categorical data. Mean (± standard deviation) was used for normally distributed continuous data. The significance of differences between the two groups was examined by Student’s t-test or Mann-Whitney U test (as appropriate). The χ2 test of independence was used for qualitative variables (Yates’ correction and Fisher’s exact test were used wherever appropriate). Correlations and association between various variables were studied using the Pearson and/or Spearman test. A probability level of P <.05 was taken as significant.