Cannabinoid receptor gene polymorphisms and cognitive performance in patients with schizophrenia and controls

Objective: To test the hypothesis that genetic variations of cannabinoid receptors contribute to the pathophysiology of cognitive deficits in schizophrenia. Methods: In this genetic association case-control study, cannabinoid receptor polymorphisms CNR1 rs12720071 and CNR2 rs2229579 were tested for association with neurocognitive performance in 69 patients with schizophrenia and 45 healthy controls. Neurocognition was assessed by the Brief Assessment of Cognition in Schizophrenia (BACS). Results: We found a consistent association between CNR1 rs12720071 polymorphism and the cognitive performance of patients in several cognitive domains. Patients with C/C polymorphism presented significantly worse performance in motor speed, verbal fluency, attention/processing speed and reasoning/problem solving. Conclusion: Although limited, our data support the hypothesis that CNR1 variations may be associated with the pathogenesis of cognitive deficits of schizophrenia.

Cannabinoid receptor gene polymorphisms and cognitive performance in patients with schizophrenia and controls.

OBJECTIVE: To test the hypothesis that genetic variations of cannabinoid receptors contribute to the pathophysiology of cognitive deficits in schizophrenia. METHODS: In this genetic association case-control study, cannabinoid receptor polymorphisms CNR1 rs12720071 and CNR2 rs2229579 were tested for association with neurocognitive performance in 69 patients with schizophrenia and 45 healthy controls. Neurocognition was assessed by the Brief Assessment of Cognition in Schizophrenia (BACS). RESULTS: We found a consistent association between CNR1 rs12720071 polymorphism and the cognitive performance of patients in several cognitive domains. Patients with C/C polymorphism presented significantly worse performance in motor speed, verbal fluency, attention/processing speed and reasoning/problem solving. CONCLUSION: Although limited, our data support the hypothesis that CNR1 variations may be associated with the pathogenesis of cognitive deficits of schizophrenia.

Family burden in schizophrenia: the influence of age of onset and negative symptoms.

OBJECTIVES: To investigate the determinants of family burden in a sample of patients with schizophrenia and their caregivers. METHODS: Thirty-one stable patients with schizophrenia and their main caregivers were recruited. Sociodemographic variables were assessed in a semi-structured interview, and positive and negative symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS). Cognitive performance was assessed with the Schizophrenia Cognition Rating Scale (SCoRS). Levels of burden on caregivers were assessed with the Family Burden Interview Schedule (FBIS). Interactions among variables were analyzed using Pearson correlations and linear regression analysis. RESULTS: Objective and subjective FBIS scores were 1.9 (standard deviation [SD] = 0.5) and 2.4 (SD = 0.6) respectively. Objective burden correlated positively with positive and negative symptoms, and cognitive impairment. Subjective burden correlated positively with positive symptoms and negatively with mean age of disease onset. Positive, negative and cognitive symptoms accounted for 47.6% of the variance of objective burden, with negative symptoms accounting independently for 30.3%. Age of onset, parents as caregivers and positive symptoms accounted for 28% of the variance of subjective burden, with age of onset independently explaining 20.3%. CONCLUSION: Patients' clinical and sociodemographic variables are important determinants of family burden in schizophrenia. Objective burden is predicted by symptoms, particularly negative ones. Subjective burden is predicted by symptoms and sociodemographic variables, particularly age of disease onset.