Paranoia impacts facial emotion recognition in schizophrenia
medwireNews: Researchers report that patients with schizophrenia differ in their ability to recognize facial emotions depending on whether they have the paranoid or non-paranoid subtype.
They found that patients with paranoid schizophrenia (PS) performed worse than mentally healthy individuals, but better than those with non-paranoid schizophrenia (NPS), in recognizing the emotion of faces that were morphed to show a continuum of emotional intensity.
"We also demonstrated that recognition accuracy for facial emotions… increased as the intensity of the expression increased," note Shen-Long Howng (Kaohsiung Medical University Hospital, Taiwan) and team in Psychiatry Research.
Using signal detection theory, the researchers assessed the facial emotion recognition performances of 44 patients with PS, 30 with NPS, and 80 mentally healthy individuals, who served as controls.
Overall, patients with schizophrenia performed significantly worse than controls in recognizing both negative (anger, sadness, surprise, and disgust) and positive (happiness) emotions.
"Our result supports the argument that the facial emotion recognition impairment in schizophrenia may reflect a generalized deficit rather than a negative-emotion specific deficit," the researchers comment.
This appeared to be true for patients with NPS when compared with controls, whereas patients with PS appeared to show specific deficits for negative emotions.
When the three groups were assessed separately, the NPS group performed significantly worse than controls in the recognition of all basic emotions and neutral faces and the PS group performed significantly worse than controls in the recognition of angry faces only, while the PS and NPS groups differed in the recognition of happiness, anger, sadness, disgust, and neutral faces.
With regards to emotion intensity, the PS group's performance was more similar to that of the NPS group when emotional expression was less intense (below 40%), whereas it was more like that of the controls at higher intensities of emotional expression (more than 70%).
"In other words, patients were more impaired than healthy comparison subjects in identifying high-intensity expressions, even though this was an easier task than identifying low-intensity expressions," Howng and co-workers comment.
The researchers call for further studies to be undertaken with larger sample sizes and comprehensive measures such as cognitive function and brain imaging studies, and a prospective study design with pharmacological and non-pharmacological interventions to "clarify the neuroanatomical/non-pharmacological distinctions between paranoid and non-paranoid schizophrenia as well as the relevance to clinical and functional outcome."
medwireNews (www.medwirenews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2013
By Lucy Piper, Senior medwireNews Reporter