Here is a list of useful links of other organisations who work in similar areas to hoarding:
Association of Professional Declutters and Designers
APDO members offer practical, sympathetic help to organise homes and workplaces. They represent the organising industry and shares expertise with media, PR and events. They also offer training, mentoring, networking, promotion and support for professional organisers.
Rehab Recovery offers a free helpline and intervention service for people suffering from eating disorders.
The Declutter Coach
The Declutter Coach provide articles that will help you change your thoughts and the things you say to yourself so that you can take small steps that will make a big difference.
Addiction Campuses (Resource from the US)
Addiction Campuses offer guides for understanding hoarding and offers advice on the help and treatment options that are on offer for those suffering with hoarding.