To our knowledge, this is the first study investigating and comparing facial expressions in patients with schizophrenia and those with obsessive-compulsive disorder using the FACS system. As expected, the healthy controls showed more appropriate experience of emotion and facial expression than patients with schizophrenia and those with obsessive-compulsive disorder. It is known that patients with schizophrenia are impaired in their ability to discriminate and recognize emotions expressed by others, have difficulty in expressing their own emotional states, and show a marked deficiency in facial expression that may be correlated with length and type of pharmacological treatment.13
Doop et al showed that worse social functioning is correlated with errors in recognition of emotional expressions on the face, and that patients with schizophrenia show general deficits in processing of emotional expressions which, in turn, are associated with worse symptoms and reduced social functioning.34
However, an emotion subjectively or objectively “experienced” by patients may be different from the emotion “recognized” by patients. For instance, a patient may recognize that a video is happy, but due to his/her affective psychopathology, experience sadness.
The results obtained by administration of the post film questionnaire showed that patients with schizophrenia and those with obsessive-compulsive disorder showed fewer concordant responses compared with healthy people (). It is interesting to note that there was no significant difference between the results for patients with schizophrenia and those with obsessive-compulsive disorder (), indicating that patients with obsessive-compulsive disorder have an impairment almost identical to that in patients with schizophrenia with regard to experiencing emotions, even though this kind of impairment is usually considered a classical phenomenon related to schizophrenia and not to obsessive-compulsive disorder.35
This finding is strengthened by the scoring of facial activity in response to video clips eliciting emotion, ie, patients with obsessive-compulsive disorder showed mimic emotional responses very similar to those in patients with schizophrenia, and the scores for the two groups did not differ significantly (). These findings indicate that patients with schizophrenia and those with obsessive-compulsive disorder seem to suffer from similar impairments with regard to both experiencing and expressing emotions.
This common feature increases the number of characteristics shared between the two diseases. Obsessive-compulsive disorder and schizophrenia are, in fact, considered to be neurodevelopmental disorders with dysfunctional frontal subcortical circuitry.37
A possible common neurodevelopmental origin is suggested by several lines of evidence: both obsessive-compulsive disorder and schizophrenia have a juvenile onset and chronic course; relevant neurological soft signs are present in both diseases;38
patients with obsessive-compulsive disorder and those with schizophrenia have more adverse perinatal experiences than healthy controls;38
obsessive-compulsive symptoms are clinically important phenomena in people with schizophrenia; and people with obsessive-compulsive disorder often experience psychosis.41
In line with this theory, the impaired capacity to experience and express emotions may be seen as another chronic consequence of the same neurodevelopmental origin of the two diseases.
The hypothesized common neurodevelopmental origin of impaired expression and experience of emotions in obsessive-compulsive disorder and schizophrenia is also supported by the fact that this kind of impairment is less frequent and less relevant in psychiatric patients affected by diseases with a different presumed etiopathogenesis. For example, it is known that patients with bipolar disorder42
or unipolar depression16
are more accurate in recognizing emotions than patients with schizophrenia.
This study revealed an important correlation in the overall sample of patients between affective flattening, incongruent answers to a post film questionnaire, and low FACS scores (), leading to the idea that mimic expression is a behavioral indicator of affective flattening,18
which is considered to be the most important negative symptom of schizophrenia, even if not pathognomic of the disease. Controversy surrounds the issue of whether second-generation antipsychotics are more effective than first-generation antipsychotics in the treatment of negative symptoms. However, it is undisputed that negative symptoms persist in many cases despite pharmacological treatment.43
Negative symptoms are known to be strongly connected with neurogenesis, and thus present in both schizophrenia and obsessive-compulsive disorder: Flagstad et al46
recently found that disruption of neurogenesis in the rat led to behavioral changes that mimic the negative symptoms of schizophrenia.
The results of this study also show a correlation between the severity of psychopathology and impaired ability to feel, express, and communicate emotions. A more severe psychopathological condition (measured on the BPRS scale) correlated with poorer facial expressiveness in the overall sample of patients, and more severe obsessive-compulsive symptoms (measured on the Y-BOCS scale) correlated with a minor number of concordant responses and with inappropriate mimic expression in patients with obsessive-compulsive disorder. These data partially confirm the results of previous studies13
and highlight the fact that the FACS system could be used as a reliable semi-objective method to evaluate the clinical course in patients.
The small number of participants is a major limitation of this study and, for this reason, the results can only be considered preliminary. The choice to reduce the power of FACS to a binary number (expression prototype present or absent) makes it a less sensitive measure and, as such, different degrees of more refined and subtle facial movements could not be evaluated. However, this step was deemed necessary because it reduced the possibility of codification bias. Further studies are needed to assess further the differences and similarities between emotional responses in obsessive-compulsive disorder, schizophrenia, and other psychiatric disease.