 This is a 16-week, randomized, double-blind, placebo-controlled study of Folate 2mg plus B12 400mcg, as an adjunctive therapy in approximately 240 consecutive outpatients with schizophrenia from Amanuel Hospital, which is based at Addis Ababa, Ethiopia will be enrolled and screened for eligibility. The goal is to randomize and complete 200 subjects from the 240 enrolled. A Sequential Parallel Design for Double-Blind Phase will be utilized. During the first phase of double-blind adjunctive treatment, eligible patients n200 are randomized to adjunctive treatment with either folate and vitamin B12 n60 or placebo n150, with a 2:3:3 ratio for random assignment to the treatment sequences drugdrug DD; n70, placeboplacebo PP; n70, and placebodrug PD; n75, while all continue to receive their antipsychotic agent for the entire duration of the study. Assuming a 10 drop-out rate during the first phase, 126 patients on placebo will complete the first 56-day phase, and 54 patients on folate and vitamin B12 will complete the first 56-day phase. 