Using data from nearly 10,000 adults in the US and UK, psychedelic use over a two-month period was not linked to changes in psychotic symptoms overall. However, among people with a personal or family history of bipolar disorder, psychedelic use was associated with an increase in symptoms. Conversely, those with a personal history of psychotic disorders experienced a decrease in symptoms. These findings suggest that the effects of psychedelics on psychotic symptoms depend on an individual's psychiatric history.
Lifetime MDMA use was not significantly associated with meaning in life overall, but a significant interaction emerged: among Swedish adults with a history of childhood trauma, those who had ever used MDMA reported higher meaning in life than those who had not. Meaning in life was measured using the presence subscale of the Meaning in Life Questionnaire. The findings suggest MDMA use may relate to psychological resilience in trauma-exposed populations, though further longitudinal and experimental research is needed to test causal direction.