Cabergoline Induced Pathological Gambling in an Adolescent with Prolactinoma

Prolactinomas are the most common hormone-secreting pituitary adenomas in adolescents. Dopamine agonists (DA) are used as first-line medical treatment. DAs are associated with an array of physical side effects; however, impulse control disorders (ICDs), such as pathological gambling (PG), have also been reported in adults. A 15.7-year-old male with no psychiatric history was referred for headache and elevated prolactin (PRL) levels. He was diagnosed with PRL-secreting pituitary macroadenoma. After initiating DA therapy with cabergoline (CBG), normalization of PRL levels and a considerable decrease in tumor size were observed. Central hypothyroidism and adrenal insufficiency present at the time of diagnosis were resolved. CBG dose was adjusted according to the test results over time. However, after two and a half years of therapy (while using 1.5 mg CBG per week), the patient developed PG, incurring debts and affecting familial relationships. Upon reducing the CBG dosage, PG symptoms ceased. This is the first case report of an adolescent with a PRL-secreting macroadenoma who developed PG as a side effect of CBG treatment. This case highlights the need for careful monitoring of psychiatric symptoms in pediatric patients with prolactinoma on DAs.