No abstract

Several hypotheses involving alterations of the immune system have been proposed among etiological explanations for psychotic disorders. The endocannabinoid system (ECS) has a homeostatic role as an endogenous neuroprotective and anti-inflammatory system. Alterations of this system have been associated with psychosis. Cannabis use is a robust risk factor for these disorders that could alter the ECS signalling. In this study, 95 patients with a first episode of psychosis (FEP) and 90 healthy controls were recruited. Protein expression of cannabinoid receptor 2 (CB2), the protein levels of the main endocannabinoid synthesizing enzymes N-acyl phosphatidylethanolamine phospholipase (NAPE) and diacylglycerol lipase (DAGL), and of degradation enzymes fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) were determined by western blot analysis in peripheral blood mononuclear cells (PBMCs). Patients with a FEP showed a decreased expression of CB2 and of both endocannabinoids synthesizing enzymes (NAPE and DAGL) in comparison to healthy controls. After controlling for age, gender, body mass index, and cannabis use, NAPE and DAGL expression remained significantly decreased, whereas FAAH and MAGL expression were increased. On the other hand, FEP subjects with history of severe cannabis use showed a larger ECS dysregulation compared with healthy controls. These results indicate an ECS dysregulation in PBMC of FEP patients. The alteration of the ECS presented at the initial phases of psychosis could be contributing to the pathophysiology of the disease and constitutes a possible biomarker of psychotic disorders and an interesting pharmacological target to take into account for therapeutic purposes.

These results suggest that abnormal immune response is present before the effects of medication and other confounders had taken place. Increased immune parameters might underlie the high ratio of medical co-morbidities described in schizophrenia.

(1) Background: The cognitive reserve (CR) concept has not been precisely defined in severe mental disorders and has been estimated using heterogeneous methods. This study aims to investigate and develop the psychometric properties of the Cognitive Reserve Assessment Scale in Health (CRASH), an instrument designed to measure CR in people with severe mental illness; (2) Methods: 100 patients with severe mental illness (non-affective psychoses and affective disorders) and 66 healthy controls were included. The internal consistency and convergent validity of CRASH were assessed. Spearman’s correlations coefficients were also performed to examine the relationship between CRASH and neuropsychological tests, psychosocial functioning, and clinical course; (3) Results: The internal consistency was high (Cronbach’s alpha coefficient = 0.903). The CRASH global score had a large positive correlation with the Cognitive reserve questionnaire total score (r = 0.838, p < 0.001), demonstrating good convergent validity. The correlation coefficients between the CRASH total scores and clinical, functional, and neuropsychological performance were different between groups. In order to provide clinical interpretation, severity classification based on diagnosis (non-affective psychotic disorders, affective disorders, and healthy controls) have been created; (4) Conclusions: CRASH is the first CR measure developed specifically for patients with severe mental illness, facilitating reliable and valid measurement of this construct. The scale may aid in the stratification of patients and the implementation of personalized interventions.