Cannabis use in early psychosis is associated with reduced glutamate levels in the prefrontal cortex

Recent studies have shown that cannabis may disrupt glutamate (Glu) signaling depressing Glu tone in frequent users. Current evidence have also consistently reported lower Glu-levels in various brain regions, particularly in the medial prefrontal cortex (mPFC) of chronic schizophrenia patients, while findings in early psychosis (EP) are not conclusive. Since cannabis may alter Glu synaptic plasticity and its use is a known risk factor for psychosis, studies focusing on Glu signaling in EP with or without a concomitant cannabis-usage seem crucial

Effect of high-potency cannabis on corpus callosum microstructure

BACKGROUND: The use of cannabis with higher Δ9-tetrahydrocannabinol content has been associated with greater risk, and earlier onset, of psychosis. However, the effect of cannabis potency on brain morphology has never been explored. Here, we investigated whether cannabis potency and pattern of use are associated with changes in corpus callosum (CC) microstructural organization, in patients with first-episode psychosis (FEP) and individuals without psychosis, cannabis users and non-users. METHOD: The CC of 56 FEP (37 cannabis users) and 43 individuals without psychosis (22 cannabis users) was virtually dissected and segmented using diffusion tensor imaging tractography. The diffusion index of fractional anisotropy, mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity was calculated for each segment. RESULTS: Across the whole sample, users of high-potency cannabis had higher total CC MD and higher total CC AD than both low-potency users and those who never used (p = 0.005 and p = 0.004, respectively). Daily users also had higher total CC MD and higher total CC AD than both occasional users and those who never used (p = 0.001 and p < 0.001, respectively). However, there was no effect of group (patient/individuals without psychosis) or group x potency interaction for either potency or frequency of use. The within-group analysis showed in fact that the effects of potency and frequency were similar in FEP users and in users without psychosis. CONCLUSIONS: Frequent use of high-potency cannabis is associated with disturbed callosal microstructural organization in individuals with and without psychosis. Since high-potency preparations are now replacing traditional herbal drugs in many European countries, raising awareness about the risks of high-potency cannabis is crucial

Negative emotion dysregulation is linked to the intensity of suicidal ideation in a mixed inpatient sample

Background: Suicide has been associated with dysfunctional strategies for emotion regulation but, so far, research findings have been inconclusive. Methods: To investigate how difficulties in emotion regulation impact suicidal ideation (SI) and behavior, 111 psychiatric inpatients were enrolled. Affective instability (AI), emotional impulsivity (EI), and negative and positive emotionality (NE and PE) were measured by the RIPoSt-40 questionnaire; the first three subscales have been summed to form a total negative emotion dysregulation (NED) score. Results: In the sample, 55 subjects reported at least one-lifetime suicide attempt; 50 patients were diagnosed with mood-disorder (MD), 30 with the schizophrenia-spectrum disorder (SSD), and 15 with personality-disorder (PD). Diagnostic groups differed for NED scores (p=.008) but not for PE (p&gt;0.05), with patients suffering from PD having higher scores (p=0.03). Compared to non-attempters, lifetime-suicide attempters were 6.5 times more likely to have a personality disorder (95% CI=1.34/31.83). Partial correlation analyses, controlling for the presence of suicide attempts, showed that lifetime SI-intensity score was significantly and positively associated with NED (r=.39, p&lt;.001), AI (r=.40, p&lt;.001), and NE (r=.42, p&lt;.001). NED scores (p=.001) and the presence of lifetime suicide attempts (p&lt;.001) were independently associated with lifetime SI-intensity scores. Limitations: The lack of a non-clinical control group and the cross sectional nature of the study limits the generalizability of the results. Conclusion: Our findings support the hypothesis that negative emotion dysregulation is independently associated with SI and behavior. Negative emotion dysregulation should be targeted in suicide prevention