The authors report the assessment of 2 patients on interferon alpha
(IFN-alpha) therapy for chronic myelogenous leukemia who developed manic
symptoms long after IFN-alpha therapy had been initiated. These cases
suggest that chronic IFN-alpha therapy may be associated with vulnerability
for developing overt psychiatric symptoms, particularly in cases where the
patient is experiencing psychosocial stress, and that the current
definition of persistent adverse effects of IFN-alpha should be broadened
to include the occurrence of manic episodes.