KityStar,
Thank you for your question.
There is evidence that using Celexa (citalopram) and Buspar (buspirone) increase the risk of developing serotonin syndrome. You can read more about serotonin syndrome here. You should speak with your doctor about the symptoms that you're experiencing. Tell him or her when the symptoms started, how often they occur, the severity level, and any other information you have about the symptoms.
Best of luck,
Casey