Facial expression-based indicators of schizophrenia: Evidence from recent research

Impaired ability to recognize emotion in other's face (decoding) or to express emotion through the face (encoding) are considered critical in schizophrenia. The topic of research draws considerable attention since clinicians rely heavily on the patient's facial expressions for diagnosis and on the patient's ability to understand the clinician's communicative intent. While most researchers argue in favor of a generalized emotion deficit, others indicate an emotion-specific deficit in schizophrenia. An early review (Mandal et al., 1998) indicated a possible breakdown in perception-expression-experience link of emotion; later reviews (Kohler et al., 2010; Chan et al., 2010) pointed to a generalized emotion processing deficit due to perceptual deficits in schizophrenia. The present review (2010-2022) revisits this controversy with 47 published studies (37 decoding, 10 encoding) conducted on 2364 patients in 20 countries. Schizophrenia is characterized by reduced emotion processing ability, especially with negative symptoms and at an acute state of illness. It is however still unclear whether this dysfunction is independent of a generalized face perception deficit or of subjective experience of emotion in schizophrenia.