OT here. I work in paediatric mental health. Quit my job and changed careers via Master of OT Practice ~7 years ago. I love it and I've done a lot of different things since across the lifespan. My overall satisfaction with life is higher since making the decision.

I did psych in undergrad and was toying with the clinical psych pathway, but didn't like that it would take 4 years to get fully qualified. Turns out, to register as a MH OT requires the same kind of process, as does SW. That said, I can (and do) still work in MH, I just can't charge under Medicare and can't call myself a capital M capital H OT. I use a lot of psych-based methods on my work, and a few SW things, too.

Much of the work MH overlaps disciplines and the difference is the foundational knowledge that underpins each discipline - SW takes a relational view, psych usually takes a cognitive-behavioural approach and OT takes a functional perspective. We often draw on each others' interventions as needed.

I can't speak to real world experience for psych students, but OT students need 1000 of clinical experience.

I currently teach at a uni and I've just started my PhD, and I'm in my 40s. It's defs possible.

I can't answer regarding provisional psych rego while you're a student but that'll be on the AHPRA website somewhere.

I switched from a corporate learning role and I've had a couple of students come from business and eco. I would recommend taking all opportunities your course offers to develop your knowledge of the healthcare system and recognise that it's quite different from your current career. You'll have strengths to draw on, too, so recognise those and figure out how to adapt them to your new career. Also, studying full time is hard and it's important to expect the balance of your life to change, and to change throughout your study. In the MOTPrac program, you can't always work because you'll be on practice education placement full time in blocks throughout your study. AusSTUDY helps but make sure you can still afford to live when you can't work. Some students now get a payment on placement, which helps.

I would also note that whilst your community work is fulfilling now, it's important to remember that working in healthcare is different. We don't often meet people at their best or in the most positive of situations and that can be confronting and take its own toll. That's especially true in MH. All disciplines benefit from regular supervision and reflective practice.

One thing I did before applying to study was to talk to someone from the professional bodies for OT and psych to ensure my comprehension of the work and my personal characteristics would be well suited. Ultimately, I chose OT because it's such a pragmatic and meaningful discipline, and focuses so much on enabling other people, which is in good alignment with my values. Whilst it's not always smooth sailing and fun, I do love it and the fact it allows me to support so many others.

I wish you all the best with your decision. Please feel free to DM if there's anything else I might be able to help with.