Cannabis remains the most commonly used illegal drugs in individuals having schizophrenia and about 43% of patients using the natural product were found to meet the required criteria for a condition called cannabis use disorder (CUD); this is against the 3% of the general population in the United States. The use of cannabis for a long term has been shown to worsen the case of patients with schizophrenia, which will lead to the worsening of the associated symptoms. Furthermore, it can decrease response to antipsychotic medication and increase the risk of psychotic relapse.
There is a link between the use of cannabis and a reduction in cognition in individuals in a good state of health. However, there is a measure of contraditory information on the effect of cannabis on cognition in individuals having schizophrenia. Additionally, two meta-analyses and several studies have revealed that the use of cannabis in schizophrenia is linked to improvement in cognitive function when compared to patients that do not use cannabis. It equally affects verbal fluency, processing speed, attention and working memory. This paper will consider the relationship between marijuana and schizophrenia.
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Samples of blood were collected from patients in the morning few seconds before they carry out the cognitive testing and fMRI scanning. The Positive and Negative Scale (PANSS), Cannabis Withdrawal Scale (CWS) and the Marijuana Craving Questionnaire (MCQ) were all given to the patient for the assessment of change in positive and negative, withdrawal and marijuana craving. With time as the within-subjects factor and group as the between-group factor; this was followed by post-hoc analysis with the use of the LSD test by Tukey for pairwise comparisons.
The Wechsler Adult Intelligence Scale (WAIS) is used for assessing the change in the performance of working memory as induced by THC and cannabis. Letter Number Sequencing Test was equally given to the patient about 30 minutes after the scanning sessions ended. This test was chosen due to the availability of other methods. Therefore, leading to the application of the test to study design for the repeated- measure.
The evaluation of WM performance change in patients was carried out using repeated measures ANOVA. Also, the magnitude of DMN-ECN and WM performance was analyzed for correlation analysis, while anti-correlation analysis was done between the DLPFC component of the ECN and the MPFC component of the DMN.
A 3T Philips Achieva fMRI scanner fitted with an eight channel head coil was used in deriving the fMRI data. Each of the patients was taken through a couple of 8-minute resting scans in the course of the study while they have their eyes opened; one test was carried out during the intervention session, while the other was done at baseline. The resting state data were compiled in a transverse position to the AC-PC plane, while the T2-weighted single-shot echo planar image pulse sequence originally designed for measuring whole brain BOLD contrast with optimal spatial and temporal resolution.
On the other hand, the T1-weighted anatomic reference images were equally acquired in similar thickness and places shortly after the resting scans.
The analysis of resting state data was carried out with a seed-driven approach. Methods minimizing the influence of artifact and motion; it equally permits the valid anticorrelated and identification of correlated networks.
The functional connective it of the DMN in patients having schizophrenia accompanied by CUD was investigated in the course of this study. Also, it looked into the effects of cannabinoid administrations. Patients subjected to the dual diagnosis displayed ECN and DMN. Conclusively, cannabis tends to worsen cognitive function in patients with schizophrenia.