Would you like to be in a study for people with Chronic Fatigue Syndrome? Stanford University is seeking participants for a Clinical Trial entitled: Phase 2, Randomized, Double-Blind, Placebo Controlled, Parallel Group Study to Evaluate the Safety, Tolerability, and Efficacy of Methylphenidate Hydrochloride as a treatment for Chronic Fatigue Syndrome in Patients taking a CFS-Specific Nutrient Formula. Our team is looking for participants between 18 and 59 years old who suffer from cognitive impairment who are not on CNS stimulants or valcyte. This study requires 4 visits at Stanford as well as 4 telephone contacts. As part of the study, participants will be compensated for their time at the Stanford location. Participation in the study involves doing a 20-30 minute phone-screening interview. If you are eligible, you will be invited to come to Stanford for: 3 study visits and 1 screen visit within a 3 and 1/2 month period. You will be compensated with $50 4-6 weeks after each study visit (3 visits) at Stanford to reimburse you for your time and participation. If you are interested in participating or have any questions, please contact one of the study coordinators, Jane Norris, at (650) 723-8126 or Ian Valencia, at (650) 723-7328, For general information about participant rights, contact 1-866-680-2906.