INTRODUCTION: A number of studies indicate a higher risk for psychosis as well as for neurocognitive deficits in healthy cannabis users. However, little is known about the impact of cannabis use on outcome in schizophrenia. In fact, there is growing evidence that cannabis-using schizophrenic patients may show preserved or even better neurocognitive performance compared to schizophrenic non-users. METHODS: We measured mismatch negativity (MMN) to investigate preattentional neurocognitive functioning in long-term abstinent chronic cannabis users with (SZCA n=27) and without schizophrenia (COCA n=32) compared to schizophrenic patients (SZ n=26) and healthy controls (CO n=34) without any chronic drug use. RESULTS: Healthy cannabis users showed reduced frontal MMN compared to controls (p=0.036). In contrast, cannabis-using schizophrenic patients showed increased frontal MMN compared to schizophrenic patients without cannabis use (p=0.038). Comparing non-cannabis users, schizophrenic patients showed reduced frontal MMN (p=0.001). No significant differences were found between CO and SZCA (p=0.27), and COCA and SZCA (p=0.50). CONCLUSION: Results suggest that chronic cannabis use may have different effects on preattentional neurocognitive functioning in schizophrenic patients when compared to healthy subjects. This may be related to preexisting differences in the endocannabinoid system between schizophrenic patients and healthy subjects. However, due to the naturalistic design of the study, the results must be interpreted with caution.
INTRODUCTION: A number of studies indicate a higher risk for psychosis as well as for neurocognitive deficits in healthy cannabis users. However, little is known about the impact of cannabis use on outcome in schizophrenia. In fact, there is growing evidence that cannabis-using schizophrenicpatients may show preserved or even better neurocognitive performance compared to schizophrenic non-users. METHODS: We measured mismatch negativity (MMN) to investigate preattentional neurocognitive functioning in long-term abstinent chronic cannabis users with (SZCA n=27) and without schizophrenia (COCA n=32) compared to schizophrenicpatients (SZ n=26) and healthy controls (CO n=34) without any chronic drug use. RESULTS: Healthy cannabis users showed reduced frontal MMN compared to controls (p=0.036). In contrast, cannabis-using schizophrenicpatients showed increased frontal MMN compared to schizophrenicpatients without cannabis use (p=0.038). Comparing non-cannabis users, schizophrenicpatients showed reduced frontal MMN (p=0.001). No significant differences were found between CO and SZCA (p=0.27), and COCA and SZCA (p=0.50). CONCLUSION: Results suggest that chronic cannabis use may have different effects on preattentional neurocognitive functioning in schizophrenicpatients when compared to healthy subjects. This may be related to preexisting differences in the endocannabinoid system between schizophrenicpatients and healthy subjects. However, due to the naturalistic design of the study, the results must be interpreted with caution.
Authors: Nicole Pesa; Daniel F Hermens; Robert A Battisti; Manreena Kaur; Ian B Hickie; Nadia Solowij Journal: Psychopharmacology (Berl) Date: 2012-03-09 Impact factor: 4.530
Authors: Michael Avissar; Shanghong Xie; Blair Vail; Javier Lopez-Calderon; Yuanjia Wang; Daniel C Javitt Journal: Schizophr Res Date: 2017-07-11 Impact factor: 4.939