just adding onto the previous persons reply, a lot of schools have schemes where you volunteer to read with children with learning disabilities. you can just email in and ask if they have these schemes in place if they're not already advertised. you could also complete moocs to show your interest. some hospitals (community hospitals in particular) have some volunteering places that you could take up. have a chat with you head of year and see if they can get into contact with local care homes, schools and hospitals. in fact, you could ask to do some work experience within your own school (not sure how feasible and related it would be to psych tho)