Hobbies / interests correlated with Big 5 scores?
Yes. One example is that people high in Openness to New Experiences are interested in aesthetic experiences including museums and being in nature, and novel experiences as you'd expect from the name. https://psycnet.apa.org/record/1997-08808-031

Treatment is a bit misleading here to mean 'study', because in psychology it usually means 'intervention'.