Cannabis, schizophrenia and cognition: the contribution of brain connectivity.

The lack of consensus on the issue of whether the consumption of cannabis favors neurocognition among schizophrenia-diagnosed patients or not, plus methodological problems found in available evidence and the limitations of studies focused on diagnosis and treatment for positive symptoms are sufficient reason for designing new research proposals based on recent brain connectivity models. The objective of this paper is to review available literature databases, selected for neurocognition in cannabis-using schizophrenia patients and to analyze contributions made by functional connectivity studies. Cognitive impairment among schizophrenia patients is found even before the appearance of the first psychotic symptoms. Measuring cognitive function in these patients, techniques such as fMRI and EEG have found brain impairment. Furthermore, regarding schizophrenia-diagnosed patients who use cannabis, some studies have shown less deterioration among cognitive domains, which may apparently be related with one of its components (CBD). Measuring brain connectivity can be useful for clarifying neurophysiological mechanisms of cognition in marihuana-using schizophrenia patients. Cognitive decline is generalized in schizophrenia patients and is considered fundamental for disease physiopathology.