Lithium-Induced Hypercalcemia Presenting as Catatonia in a Patient With Schizoaffective Disorder

Catatonia, a relatively rare and less explored consequence of lithium-induced hypercalcemia, represents a notable yet understudied side effect. Lithium is utilized in the management of acute mania and as a maintenance therapy for bipolar disorder. However, the specific catatonic presentation resulting from hypercalcemia remains poorly understood. Here, we present a case study involving a 55-year-old male with a history of schizoaffective disorder, bipolar type, who had been receiving lithium therapy. The patient presented with catatonia and altered mental status. Manifesting as mutism, rigidity, immobility, and staring, these symptoms were subsequently attributed to hyperparathyroidism-induced hypercalcemia. Markedly elevated levels of both calcium and parathyroid hormone (PTH) were detected in the patient's laboratory results. The patient's lithium therapy was promptly discontinued. Serum calcium and PTH levels began to decrease gradually and returned to normal limits over 29 days. The patient returned to his baseline level of functionality. There was a notable improvement in his mental status and his ability to communicate using simple sentences. This case underscores the significance of recognizing uncommon clinical presentations of hypercalcemia in patients undergoing chronic lithium therapy. Given the broad range of neuropsychiatric manifestations associated with hypercalcemia, it is crucial to enhance our understanding of this phenomenon and develop the capacity to differentiate it from primary psychiatric disturbances.