The Cannabis Pathway to Non-Affective Psychosis may Reflect Less Neurobiological Vulnerability.
Frontiers in psychiatry January 1, 2014 Else-Marie Løberg, Siri Helle, Merethe Nygård et al.
Cannabis use is common in people with non-affective psychosis and is considered a risk factor for the condition. This review of recent literature examines variables such as age of onset, cognition, brain functioning, family history, genetics, and neurological soft signs (NSS) to better understand the relationship. Compared to non-using patients, those who use cannabis appear to have fewer stable cognitive deficits, fewer NSS, and possibly more normalized brain functioning, suggesting less neurobiological vulnerability. However, familial and genetic vulnerabilities are present in the cannabis-using group, which may increase sensitivity to cannabis. An earlier age of onset in these patients indicates a different pathway to psychosis. Two vulnerability models are proposed to integrate these findings.