Self-help support groups are groups made up of people who are directly and personally affected by a particular issue, condition or concern. They are run by their members, which means that those directly affected by the issue are the ones who control the activities and the priorities of their group. While many self help groups obtain resources and assistance from outside the group, e.g. from professionals or other groups, the members are the decision-makers. Evidence strongly suggests that self-help support groups are a powerful and constructive means for people to help themselves and each other. It has been shown that the groups can make a significant contribution to positive outcomes for those who participate. There appears to be an increasing tendency for individuals to get together and form such groups.