Emotion processing in schizophrenia is state and trait dependent

Background: Substantial evidence exists about emotion processing (EP) impairments in schizophrenia patients. However, whether these deficits are present primarily during psychosis (i.e., state dependent) or an integral part of the disorder (i.e., trait dependent) remains unclear. Methods: EP was assessed with the degraded facial affect recognition task in schizophrenia patients (N = 521) and healthy controls (N = 312) at baseline (T1) and after a three year follow-up (T2). In schizophrenia patients symptomatic remission was assessed with the Positive and Negative Syndrome Scale (PANSS) remission tool. Patients were divided into four groups: remission T1 and remission T2 (RR); remission T1 and non-remission T2 (RN); non-remission T1 and non-remission T2 (NN) and non-remission T1 and remission T2 (NR). Factorial repeated measures ANCOVA was used to compare EP performance over time between groups. Age, gender and general cognition were included as covariates. Results: Schizophrenia patients performed worse than healthy controls on EP at T1 (p = 0.001). The patients that were in symptomatic remission at both time points (the RR group) performed worse than the healthy controls at T2 (p <0.001). Significant group x time interactions were found between RR and RN (p = 0.001), and between NR and RN (p = 0.04), indicating a differential EP performance over time. No group x time interaction was found between NN and NR. Conclusion: The results show relatively poor EP performance in schizophrenia patients compared to healthy controls. EP performance in schizophrenia patients was associated with symptomatic remission. The results provide support for the hypothesis that EP deficits in schizophrenia are both state and trait dependent.