Abstract
This case report presents the use of progesterone for the regulation of an atypical menstrual cycle in a girl, aged 11 years, who is also diagnosed with Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS). The progesterone injections alleviated the prolonged, heavy monthly blood flow, but also caused significant improvements in the patient's mood, behavior, and cognition within four weeks following the initial injections. The use of hormonal treatments, such as progesterone, to effect mood, behavior, and cognition should be further researched to determine other potential therapeutic uses.