Age and cannabis co-use influence the acute effects and therapeutic outcomes of psilocybin. In a cross-sectional study of 365 current psilocybin users aged 18–77, younger participants reported more adverse experiences, while older adults had milder subjective effects. However, age did not significantly affect mystical experiences, psychological insight, or psychological outcomes. Polysubstance use patterns varied by age, with younger adults more likely to co-use nicotine. Cannabis co-use was associated with greater improvements in quality of life, anxiety, depression, and alcohol abuse, suggesting potential synergies between psilocybin and THC.
Among 365 current psilocybin users aged 18–77, younger adults (18–25) reported more adverse acute experiences, while older adults (55–77) had milder effects. Age did not significantly affect mystical experiences, psychological insight, or psychological outcomes. Polysubstance use patterns differed by age: younger adults more often co-used nicotine with psilocybin. Cannabis co-use with psilocybin was linked to greater perceived improvements in quality of life, anxiety, depression, and alcohol abuse, suggesting possible synergies between psilocybin and THC. The findings indicate that age and cannabis co-use may shape some of psilocybin’s acute effects and therapeutic outcomes.