Daily use of high-potency cannabis is associated with more positive symptoms and fewer negative symptoms in first-episode psychosis patients. Among 901 patients and 1,235 controls across six European countries, those who used high-potency cannabis daily had the highest scores on positive symptoms, while negative symptoms were more common in patients who never used cannabis. Psychotic experiences in controls were linked to current cannabis use but not to lifetime use. Depressive symptoms showed no differences related to cannabis use in either group.
Precision psychiatry promises to improve psychiatric practice by grounding diagnosis and treatment in biological markers, but a conceptual analysis of its foundations reveals they are obsolete and flawed. Mental suffering cannot be reduced to biological essences, because biological processes alone cannot capture qualia, meaning, or abnormality without context. Despite its intentions, precision psychiatry does not offer a sufficiently promising alternative to current phenotype-based classification systems.
In a randomized controlled trial, mindfulness-based cognitive therapy (MBCT) reduced momentary paranoia and increased feelings of social acceptance in daily life among people with residual mood instability after major depression. Paranoia decreased significantly in the MBCT group and increased in the waiting-list control group, while social acceptance rose in the MBCT group and fell in controls. MBCT also weakened the link between paranoia and lower social acceptance. The findings suggest MBCT can interrupt social processes that maintain subclinical paranoia.