Male patients with new-onset Cannabis Induced Psychotic Disorder (CIPD) present with less severe psychotic symptoms and show greater improvement in both psychosis and cognitive deficits over four weeks of hospitalization compared to patients with psychosis unrelated to cannabis. Among 16 CIPD patients followed after discharge, 10 relapsed into psychosis within six months after resuming cannabis use. The findings suggest CIPD has a distinct short-term course with better acute resolution, but relapse of cannabis use may lead to poorer long-term outcomes. The study did not include female patients.
The balance between excitatory and inhibitory (E/I) activity in the brain is important for normal function, and its disruption is linked to psychiatric disorders. In a randomized, double-blind, placebo-controlled study, healthy volunteers received low doses of ketamine (which shifts E/I balance toward excitation) and thiopental (which shifts it toward inhibition) while their brain activity was recorded with EEG. The drugs altered the aperiodic exponent of the power spectrum in opposite directions, matching computational predictions. Changes in the exponent correlated with subjective and cognitive effects, suggesting that this measure could serve as a noninvasive EEG biomarker for transient shifts in cortical E/I balance.