Cognitive Empathy and Longitudinal Changes in Temporo-Parietal Junction Thickness in Schizophrenia

The Effects of Cannabidiol and δ-9-Tetrahydrocannabinol in Social Cognition: A Naturalistic Controlled Study

Background: Social cognition abilities such as empathy and the Theory of Mind (ToM) have been shown to be impaired in neuropsychiatric conditions such as psychotic, autistic, and bipolar disorders. The endocannabinoid system (ECS) seems to play a role in social behavior and emotional processing while it also seems to play a role in those neuropsychiatric conditions showing social cognition impairments. Main plant cannabinoids delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) modulate the ECS and, due to their opposite effects, have been proposed as both cause and treatment for neuropsychiatric-related disorders such as schizophrenia, anxiety, or post-traumatic stress disorder (PTSD). The aim of this study was to test the effects of THC and CBD on social cognition abilities in chronic cannabis users. Method: Eighteen members from a cannabis social club were tested for social cognition effects under the effects of different full spectrum cannabis extracts containing either THC, CBD, THC+CBD, or placebo in a naturalistic randomized double-blind crossover placebo-controlled study. Results: Results showed that participants under the effects of THC showed lower cognitive empathy when compared with the effects of CBD but not when those were compared with THC+CBD or placebo. Also, participants showed higher cognitive ToM under the effects of CBD when compared with the effects of placebo, but not when those were compared with THC or THC+CBD. However, we did not find differences on the emotional scales for empathy or ToM. Conclusions: This study provides evidence for the interaction between the effects of THC and CBD and social cognition abilities in a naturalistic environment, which can be of special interest for the clinical practice of medical cannabis on neuropsychiatric disorders. We show for the first time that CBD can improve ToM abilities in chronic cannabis users. Our results might help to understand the role of the ECS in social cognition, and their association with psychiatric and neurodevelopmental disorders such as schizophrenia or autism. Finally, we demonstrate how reliable methodologies can be implemented in naturalistic environments to collect valid ecological evidence outside classic laboratory settings.

Correlation analysis and gender differences of cognitive function based on mini-mental state examination (MMSE) and suicidal tendency in patients with schizophrenia

BACKGROUND

The aim of this study was to investigate the correlation and gender differences between cognition and suicidal tendency in patients with schizophrenia.

METHODS

A total of 554 patients with schizophrenia were recruited. The Mini-Mental State Examination (MMSE), Positive and Negative Syndrome Scale (PANSS), Interpersonal Reactivity Index (IRI), Toronto Alexithymia Scale (TAS), and Insomnia Severity Index (ISI) were used to assess clinical symptoms.

RESULTS

In male patients, MMSE score and the incidence of suicidal tendency were correlated (P = 0.04, OR = 1.06, 95%CI: 1.00-1.12). Among patients with cognitive dysfunction, IRI score (P = 0.01, OR = 1.04, 95%CI: 1.01-1.06), and types of antipsychotic drugs (P < 0.01, OR = 3.97, 95%CI: 1.76-8.97) in male patients were associated risk factors for suicidal ideation. Among patients without cognitive dysfunction, PANSS positive subscale score (P = 0.03, OR = 1.06, 95%CI: 1.01-1.11), and PANSS general psychopathology score (P = 0.02, OR = 1.05, 95%CI: 1.01-1.08) were associated risk factors for suicidal ideation in male patients and PANSS positive subscale score (P < 0.01, OR = 1.15, 95%CI: 1.05-1.26) were associated risk factors for suicidal ideation in female patients.

CONCLUSIONS

There were significant gender differences in the correlation between cognitive functioning and suicidal ideation in patients with schizophrenia. Cognitive function may play an important mediating role in other factors on suicide.

Association of empathy with clinical symptoms and cognitive function in Chinese chronic schizophrenia patients with and without deficit syndrome

BACKGROUND

Patients with deficit syndrome (DS) are known to experience cognitive impairment. However, there is no consistent conclusion on the impairment of neurocognitive features in DS patients, and no studies have examined their empathy. The purpose of this study was to compare neurocognition and empathy in patients with DS and non-DS schizophrenia.

METHODS

Totally, 665 patients with chronic schizophrenia were enrolled. DS patients were identified by the Proxy Scale for Deficit Syndrome (PDS). Neurocognition and social cognition were assessed by Repeatable Battery for the measurement of Neuropsychological Status (RBANS) and the Interpersonal Reactivity Index (IRI), respectively. In addition, psychopathological symptom severity was assessed by the Positive and Negative Syndrome Scale (PANSS).

RESULTS

Participants included 150 patients with DS and 140 patients with non-DS. DS patients performed significantly worse on the all RBANS domain (except for visuospatial) and total scores as well as IRI scores. Regression analysis showed that PANSS general psychopathology and education were associated with RBANS total score in the DS group (adjusted R² = 0.29), while education and PANSS negative symptoms were correlated with RBANS total score in non-DS patients (adjusted R² = 0.33). In the non-DS group, suicide attempts and PANSS negative symptom score were independently associated with IRI total score (adjusted R² = 0.06), whereas in the DS group, no variable was associated with IRI total score.

CONCLUSIONS

Our findings suggest that patients with DS may have poor neurocognitive and empathy performance. In chronic schizophrenia patients, negative symptoms may play a different role in cognition between DS and non-DS groups.