Mondelli V, et al. - Whether baseline levels of complement component 4 (C4) have any role in predicting worse clinical results at 1-year follow-up among patients suffering from first episode psychosis, was determined in this naturalistic longitudinal study. Researchers analyzed cases with first episode psychosis (n = 25) at baseline as well as during prospective follow-up. Significantly higher baseline C4 levels were detected among non-responders vs responders when controlling for baseline psychopathology and baseline concentrations of C reactive protein. An area under the ROC curve of 0.795 was generated for the ability of C4 levels to differentiate responders from non-responders, and the threshold point for C4 to discriminate between responders and non-responders seemed to be approximately 490 mcg/ml. As per these preliminary observations, baseline C4 levels have the utility as a predictor of clinical outcome at 1-year follow-up among patients with first episode psychosis.