"Confused about mental health services"

After being healthy his whole life, my dad recently started to suffer from mental health problems and ended up, after a trip to A&E, being sectioned for 3/4 months with a diagnosis of psychotic depression. It was serious enough to warrant electro convulsive therapy and my father has thankfully now been discharged but he is not well and it very much feels as though he ought to be getting psychological intervention - I am concerned he will have a relapse.

The problem is its not really clear who is responsible (as dad's partner has health needs of her own and is struggling) and who I can make representations to and would be grateful for some help on this.

He lives in Ruskington, Lincolnshire. He was initially hospitalised in the Manthorpe Centre in Grantham and then moved to Brant Ward, Witham Court, Lincoln. He is now at home and I understand (although am not certain) that the consultant at the Manthorpe Centre (rather than his GP) is ultimately responsible for his treatment. I understand that dad has a CPN and also that someone from the Willows in Sleaford has been in touch but nothing has yet come of that.

I believe that this is all under the umbrella of the Lincolnshire NHS Partnership NHS Foundation Trust.

I would like to find out who I should make representations to about all of this as I am not satisfied that my dad is getting the treatment which he needs.