The aim of the study: To determine the effect of adding omega3 on metabolic and inflammatory mediators in patients with schizophrenia treated with clozapine and valproate in Hejazi and Ibn e Sina hospital in Mashhad. Study design: Randomized, double-blind, placebo-controlled, single-center, phase II trial. Inclusion criteria: patients with schizophrenia admitted in Hejazi and Ibn Sina hospital in Mashhad that treated with clozapine and valproate at least 3 months (clozapine dose of 200 to 400 mg); Age 18 years or older; triglyceride levels in the morning between 200 to 499 Milligrams per deciliter; metabolic indices of patients before starting treatment with clozapine and valproate are normal. Exclusion criteria: Pregnancy or Lactation; history of sensitivity to fish oil; use of omega3 in the past few months; Having obvious bleeding disorders or a history of using heparin and coumarin; The reluctance of patients participating in the study; use of other drugs such as statins; history of consumption or abuse of alcohol or drugs within 6 months from baseline. Intervention: In the intervention group all patients who received clozapine daily 300 to 400 mg a day for 3 months receive omega3 (4 Grams per day) for 8 weeks. In the control group patients who received clozapine 300 to 400 mg a day for 3 months received placebo for 8 weeks. The primary outcome or consequences of the study: inflammatory mediators and metabolic changes. The primary outcome: Height, weight, waist circumference, body mass index, triglyceride levels, total cholesterol, LDL, HDL and CRP and inflammatory markers HSP, PAB, SOD, ZN, CU at the beginning and end of week 8.