Dynamics of Prolactin and Hormones of the Hypothalamic-Pituitary Thyroid Axis in Patients with Schizophrenia

Abstract—In 70 examined patients, 34 with the first psychotic episode (FPE) and 36 with chronic schizophrenia (CS), we studied dynamics of the prolactin (PRL), thyroid-stimulating hormone (TSH), and free thyroxine (T₄) during olanzapine therapy. Background hyperprolactinemia (HP) was observed in 52.9% of patients with FPE, which had with mean values of 971.1 ± 420 mIU/L, and in 50% of patients with CS (mean prolactin values were 1131 ± 845.4 mIU/L). In 11.8% of patients with FPE and in 16.6% of patients with CS, the level of free T₄ was below the standard values (mean values: 7.5 ± 0.3 pmol/L and 8.0 ± 0.8 pmol/L, respectively). TSH parameters in patients with FPE were within the reference values. Elevated background levels of TSH in patients with CS were observed in 11.1% of cases (4.8 ± 0.7 mIU/mL). By 6–8 weeks, an increase in mean PRL values was observed in all patients. Fluctuations in thyroid hormone levels by the end of therapy were insignificant. Four variants of dynamic changes in PRL and hypothalamic-pituitary-thyroid (HPT) axis hormones in patients during olanzapine therapy were identified. The relationship between PRL and thyroid hormones is discussed. The data obtained dictate the need to study the characteristics of the ratio of the levels of these hormones before the start of antipsychotic therapy (AT) in order to detect hypothyroidism and HP early, as well as to prevent the development of these hormonal dysfunctions in the process of AT and confirm the need to assess the levels of PRL and HPT-axis hormones in patients with FPE and CS before the start of the appointment of AT.