Charernboon T, et al. Psychiatry Investig. 2016 Sep;13(5):571-573. https://doi.org/10.4306/pi.2016.13.5.571

Objective: In the last decade, research has focused on developing novel medications for the treatment of dementia. Cannabinoids are one of the potential agents under investigation. The present study aimed to examine the evidence concerning the effectiveness of cannabinoids for the treatment of dementia. Methods: We undertook a systematic review complying to PRISMA guidelines. Four databases were searched including Medline, Embase, Cochrane Library, and PsychINFO. Results: Five studies evaluated the use of cannabinoids for anorexia and agitation in dementia. One study used dronabinol 5 mg/day to target anorexic symptoms of dementia which positively impacted on weight. Results of two trials investigating the effectiveness of tetrahydrocannabinol (THC) 1.5–4.5 mg/day for the treatment of agitation indicated no significant differences between THC and placebo. The most recent trial reported significant improvement in agitation using nabilone at 1–2 mg/day. However, levels of evidence of these agents were rated as low and very low because of low sample size and methodology issues. No studies were available that investigated the use of cannabinoids to moderate cognitive symptoms in dementia. Conclusions: Findings from a few robust randomized controlled trials suggest that nabilone might be useful for the treatment of agitation in patients with dementia, but there is no convincing evidence for THC. Additional studies are needed to further clarify and assess the benefits of these treatments. Clinical Implications: There were no randomized controlled trials investigating the use of cannabinoids for the treatment of cognitive decline in dementia. Studies on THC reported no significant improvement in agitation. It may be too early to postulate that cannabinoids have any effect on dementia symptoms or their progression.

Impairments in social cognitions in schizophrenia are increasingly reported in the last decade but only a few studies have come from Asia. The objective of the study was to evaluated emotion perception, theory of mind and social knowledge in people with schizophrenia compared to healthy controls. Participants were 36 clinically stable outpatients with schizophrenia and 36 normal controls with comparable age and level of education. We administered general neurocognition test (the Addenbrooke’s Cognitive Examination), emotion perception (the Faces Test), theory of mind (the Eyes Test) and social knowledge (the Situational Features Recognition Test; SFRT). Schizophrenia patients displayed obvious impairment in all three social cognition domains i.e. the Faces Test [13.7 (2.9) vs 15.7 (1.9), P=0.001], the Eyes Test [18.9 (4.4) vs 23.5 (4.4), P<0.001] and SFRT [0.85 (0.09) vs 0.9 (0.05), P=0.002]. The performances on three social cognition tests did not correlate with positive symptoms. Only the Faces Test seemed to be related to negative symptoms. The results demonstrated that there are deficits of social cognitions in schizophrenia even in a clinically stable population.

Background: Schizophrenia has a broad range of interrelated symptoms and impairment in functioning. The objective of the study was to explore the interplay between positive symptoms, negative symptoms, neurocognition, social cognition and real-life functioning in patients with schizophrenia using network analysis. Methods: Participants were 64 clinically stable patients with schizophrenia. Psychopathologic, neurocognition, social cognition, and functioning were measured using the Scale for the Assessment of Positive Symptoms, Scale for the Assessment of Negative Symptoms, Addenbrooke’s Cognitive Examination III, Faces test, Reading the Mind in the Eyes test, and Personal Social Performance scale. Results: The network analysis suggested that functioning was the most central in the network followed by avolition and asociality. Functioning was directly connected to avolition, asociality, blunted affect, neurocognition and emotion recognition. The positive symptoms were the most remote and therefore the least important node. Conclusion: The high centrality of functioning suggests the need for improving of everyday life skills for patients with schizophrenia. Moreover, treatment of specific negative symptoms, neurocognition and emotion recognition could also enhance functional outcome.

Until now there has not been a validated measure of theory of mind available in the Thai language. Our goal in this study was to assess the validity and reliability of our Thai-language translation of the Reading the Mind in the Eyes Test (the “Eyes Test”). We gave our Thai version of the Eyes Test to 70 participants: 30 people with schizophrenia and 40 normal controls. We also gave Thai versions of the Faces Test and the Addenbrooke’s Cognitive Examination to assess convergent validity. For known groups validity, the controls scored significantly higher than the participants with schizophrenia on the Eyes Test: 24.6 (standard deviation=3.9) versus 18.2 (standard deviation=4.1), P<0.001. The Eyes Test correlated with the Addenbrooke’s Cognitive Examination (r=0.68, P<0.001) and the Faces Test (r=0.51, P<0.001). Internal consistency by the Cronbach alpha for the Eyes Test was 0.7, and test-retest reliability by intraclass correlation was 0.92 (P<0.001). The Thai version of the Eyes Test is a valid and reliable measurement that can be used in clinical practice and in future investigations of theory of mind in neurologic and psychiatric disorders.