A mental health care charity which draws on 200 years of experience has been commended for its special and unique culture.

The Retreat, which works with the NHS to care for patients with complex and difficult needs, has also been hailed as an example of good practice in an outstanding Investors in People (IiP) report.

The inspector particularly commented on The Retreat's openness, staff enthusiasm and the knowledge that staff displayed about the business and its direction.

"Success is hard won in any walk of life and your community is very special," said the report, which has just been published.

It said The Retreat not only continued to meet IiP standards, but has made great progress towards becoming a Learning and Development organisation.

The inspector said he would recommend the not-for-profit mental health provider to other organisations keen to obtain IiP recognition. The report describes "a unique culture of inclusiveness preserving the Quaker character" and how staff are working well as "powerful autonomous professionals".

Jenny McAleese, The Retreat's chief executive, said: "We are absolutely delighted with this report which recognises our unique qualities. We value every one of our staff and this report recognises all the work we have done to preserve this special environment." Particular strengths of the organisation which were highlighted as its clarity of vision, delivery of excellence and a strong coaching and mentoring culture.

The Retreat was also commended for its staff development. The report stated: "There is not a shadow of a doubt that The Retreat values the knowledge, skills and talents of all staff equally.

"The assessor met with a number of people whose aspirations had been met through being nurtured and encouraged through preceptorship, mentoring and coaching to achieve personal growth as well as worthwhile career progression and rewards. Your approach has set the organisation on the road to becoming a true "learning organisation."

Managers were praised for their leadership and management skills.

"Directors and managers are genuine and sincere in developing all people... The management capabilities described by managers truly reflect the culture and values of your organisation and aligned with the expectations of the people they manage."

Robert Brownlow, The Retreat's director of finance, said: "Our relationships with our staff and patients are based on respect, dignity and tolerance, reflecting the humanity and spiritual values of our Quaker roots.

"It was particularly poignant, therefore, for the assessor to recognise that "sometimes performance improvement is gauged by just making someone smile."