OBJECTIVE: The prevalence of life-long bipolar disorder in patients with multiple sclerosis (MS) is higher than in normal populations. Interferon (IF) beta is one of the agents used in MS treatment. Apart from the emotional symptoms that MS can cause, the use of IF may cause affective symptoms. Often depressive symptoms are observed, but manic and psychotic symptoms can also be seen. By presenting a patient with risk factors that increase the prevalence of psychiatric disorders, including the high probability of MS-affective symptoms, the risk of IF given during the treatment to lead to depressive or manic symptoms, addition of antidepressant and steroid and even coexistence of IF and hypothyroidism, it is aimed to draw attention to MS, IF, affective symptoms and the difficulty of the treatment.
CASE: 27-year old female patient. The patient who was brought to the emergency psychiatric service by her relatives was informed that her behavior in the last week was like decreasing his sleep, laughing, talking too much and fast, increasing the amount of money spent, does not use any scarf even she was wearing hijab, and admitted to our clinic with bipolar disorder manic episode pre-diagnosis. Increased speech rate and amount, elevated emotions, euphoric mood and flight of idea were positive findings on mental status examination. There was no evidence of hypomanic or manic episodes in the patient's history. It was informed that she has been diagnosed with MS in 2012, and she was using IF β. The patient reported mild depressive symptoms and muscle pain a year earlier and started to receive 30 mg /day of duloxetine and increased doses of 60 mg /day two weeks ago. In routine examinations levothyroxine 50 mcg /day was started due to high TSH and low T4 and T3 levels, and olanzapine 15 mg /day was provided for manic episode symptoms. IF β treatment was continued. Duloxetine was stopped. A week after the onset of olanzapine, her symptoms were mostly remitted.
DISCUSSION: Since our patient has many risk factors such as the use of IF β, the recent increase of doses of duloxetine, the addition of corticosteroids, the detection of hypothyroidism, the precise cause of manic switch is unknown; perhaps it was due to the coexistence of all. Likelihood of high-rate affective symptoms in patients with MS, possible IF-induced affective symptoms, and the possibility of antidepressants to be added to the treatment to cause manic switch makes the treatment of psychiatric symptoms associated with MS difficult and requires caution.