Formal thought disorder (FTD) is a multidimensional syndrome occurring along the psychosis continuum. A meta-analysis of 19 studies including 1840 cannabis users and 3351 non-cannabis users found that cannabis users had higher severity of FTD (standardized mean difference = 0.21). This increase was present regardless of disorder severity: in healthy individuals, patients with first-episode psychosis, and patients with schizophrenia. Between-group differences were not significant. Cannabis use appears to be associated with increased FTD severity all along the psychosis continuum, consistent with its known effect on positive symptoms.
Felt presence—the sensation that someone else is nearby despite no sensory evidence—has been recognized in psychosis for over a century but has been difficult to study. Recently it has been identified across multiple diagnoses and emphasized by people with psychosis as a clinical priority. This work describes how felt presence appears in a first-episode psychosis sample and reports initial links to affect, gender, and psychopathology.
The head-twitch response (HTR) in rodents is a behavioral marker of serotonin 2A receptor activation caused by psychedelics. This work describes a method using a magnetic ear tag reporter with automated quantification and biphasic detection to measure HTR in mice given the psychedelic DOI. The approach can help study molecular mechanisms of psychosis and identify signaling processes relevant to antipsychotic and psychedelic compounds.