Long-Term Effects of Lithium Use on Children and Adolescents: A Retrospective Study from Turkey

Background: The aim of this study was to evaluate the long-term effects of lithium treatment on white blood cell (WBC) count, serum creatinine, and thyroid-stimulating hormone (TSH) levels in children and adolescents with bipolar disorder (BD) and non-BD in a Turkish children and adolescent sample.Methods: The study is based on retrospective chart review. Children and adolescent patients with BD and non-BD prescribed lithium in a mental health and neurological disorders hospital between 2012 and 2017 were included in the study. Data were collected from the electronic medical files. Laboratory values for WBC count, serum creatinine, and TSH levels at baseline within the week before the onset of lithium, and at 1st, 3rd, 6(th), and 12th month of treatment were recorded.Results: A total of 143 patients (82 females, 61 males; 100 BD, 43 non-BD) aged 9-18 were included. Non-BD diagnoses were psychotic and schizoaffective disorders, unipolar depression, attention-deficit/hyperactivity disorder, conduct disorder, severe mood dysregulation syndrome, borderline personality disorder, and autism. Mean age of the participants were 15.90 +/- 1.16 years for the bipolar group and 14.88 +/- 1.79 years for the nonbipolar group. Patients with BD reported more adverse effects. There was a statistically significant increase in WBC counts and TSH levels at any time point. A statistically significant elevation in serum creatinine was found at 3rd and 12th month of treatment. During the course of lithium treatment, WBC counts exceeded 13,000 in 14 (9.8%) patients, and TSH levels exceeded 5.5 mU/L in 41 patients (28.6%). Twenty-one (14.68%) patients were started on thyroxin replacement. Basal TSH levels and duration of the lithium treatment were higher in the participants with TSH levels exceeding 5.5 mU/L. Lithium maximum dose, lithium blood level, basal TSH level, and duration of treatment were higher in the participants receiving thyroxin replacement. No patients had serum creatinine levels exceeding the normal reference values.Conclusion: Our study suggests that lithium is a generally safe and tolerable agent for children and adolescents with BD and non-BD; however, close monitoring of thyroid functions particularly in patients with a higher basal TSH level and longer duration of lithium use is important.