8-Week Double-Blind Treatment Phase: Participants will be randomly assigned to atomoxetine or placebo using a permuted block randomization system. Treatment assignment order is random within each block, and the total number of participants assigned to each treatment are equal. The block sizes will vary in random sequence between 2 and 4. Thus, it will be difficult to ascertain the next treatment assignment, even if a participant becomes unblinded, while the imbalance of numbers between the treatment groups is kept within tight limits. The central unblinded pharmacist will be notified of the treatment assignment, and will inform unblinded pharmacists at the other sites about which study medication to dispense. Separate emergency unblinding envelopes for each participant will be kept in a locked cabinet at each dispensing pharmacy. In addition, an emergency unblinding tool will allow specific, designated staff (i.e., the P.I. and Co-P.I.) to log onto the randomization data base through the MPRC computer network and request treatment assignment for a specific participant. An electronic audit trail will be kept of all such unblinding requests. All unused unblinding envelopes must be returned unopened to the central pharmacy at the end of the study. Participants will receive biweekly BPRS, SANS, SAS, BAS, AIMS, Side effect, and vital sign assessments. Neurocognitive assessments will be performed at week 0 and week 8 or endpoint. Laboratory tests, antipsychotic levels, and the EKG will be repeated at 8 weeks.