Matt Muijen asks interesting questions about mental health services in The New NHS (Community Spirit, 22 January).

If trusts focusing on mental health are the future, how much change must there be? There are now around 430 trusts in England; 177 (40 per cent) provide mental health services, of which 150 (85 per cent) are mixed trusts. Trusts focused on mental health alone are few. There is much change in prospect.

Couple this with the management cost agenda that foresees fewer trusts, and a very different style of trust emerges. The average English trust now has an income of pounds55m-pounds60m. With fewer trusts, this average size will become a trust at the lower end of the scale.

In the area I know, west London, you need a population of more than 800,000, living in four boroughs, to create a trust with an income just pushing pounds50m. It will be small, but probably comprise 12 or more localities with community mental health teams.

The question is, can viable trust size be reconciled with a local approach? Beyond that, how can a future trust foster the community approach and not fall prey to the seduction of running acute beds? How can it stop the old asylum walls being replaced by modern virtual ones? How can it best develop the policy agenda - particularly against social exclusion - if organisationally isolated from other parts of the NHS and dealing with clients whose lives are already marginalised?

One thing is sure: resolving the dilemma will call for a very different kind of organisation and management from that we now know. Organisations will need to be very flat. Only in this way will the locality have the pivotal role and focus in providing care.

What will this mean for those who manage the trust? What happens to the roles of chief executive and operations director? How will they be developed to manage with sureness of touch across such a span? How will they let power go to the localities? What new roles will replace the traditional ones?

We shall need a lot of development and help to create a modern, dependable mental health NHS.

Richard Higgins,

Chief executive,

Parkside Health trust,

London W9.