"GP referral to voluntary services"

I wonder why GPs find it so difficult to refer to voluntary services, for instance counselling, when the NHS referral waiting list is so long?

I'd like GP surgeries to keep a directory of voluntary services and actively refer patients to them. I'd like them to advertise these services where appropriate.

This could save a lot of money by keeping people out of hospital by providing people with earlier support. Many GPs seem to consider voluntary services to be "amateur" and feel unable to recommend them.