Hi,
Accreditation is how they view your achievements (is it high quality). If you want to maximise your options in this field, I would say don't risk it, as accredited courses confers eligibility for the GBC (a requirement for Chartered Status). Later if you decide that you do want to work in this field and your course was not accredited, then you will need to do a conversion course (which would be wasting your time, as it would be what you already know). But if you are sure that you differently don't want to do a career in psychology, it doesn't matter.