Diagnoses will be made by SCID-I and DSM-IV-TR criteria, by a PhD or MD clinician (with demonstrated reliability), followed by consensus. A research pharmacist will randomly assign treatment (without stratification), and package ARI and RIS in identical-appearing capsules. A blinded clinician will measure symptoms within 3 days before antipsychotic initiation and weekly thereafter; adjust doses based on weekly evaluations of symptoms and side effects, and evaluate treatment adherence and substance use. The diagnostician, pharmacist and treating psychiatrist are otherwise uninvolved in the study. Low-dose benztropine (≤2 mg daily), lorazepam (≤1 mg daily) and antidepressant treatment will be permitted, but not adrenergic agents or anticonvulsants. Initiation, stepped, and maximal antipsychotic doses will respectively be: ARI (7.5, 7.5 and 30 mg, daily); RIS (2, 2 and 8 mg daily). If patients do not tolerate the treatment (at the minimal dose), or exhibit treatment-refractory symptoms (at the highest tolerated dose), they will discontinue the study, the blind broken, and transition into naturalistic treatment in the clinic. Receptor antagonist loads (daily dose X Haldol equivalent) will be computed for patients at unblinding, using indices for α2 and α1 receptors, D2 and muscarinic receptors. In the last half of the 8th week of antipsychotic treatment, subjects will undergo fMRI on two days, separated by one day for modafinil washout. They will receive modafinil (200 mg po) on one day and Placebo on the other (double-blind, counterbalanced), each in mid-morning, and scan 3-4 hours later, during the average peak plasma levels of modafinil 30. All subjects will provide informed consent for all procedures, approved by the UCSF IRB. This study will meet the CONSORT standard for clinical trial design, conduct and reporting.