This document discusses harm reduction and concurrent disorders. It defines harm reduction as a philosophical approach that aims to support people in reducing the negative consequences of substance use through moderating intake or safer methods of use. The key principles of harm reduction are that it is pragmatic, respectful, prioritizes goals, and maximizes intervention options. Harm reduction recognizes that people are at different stages of change and aims to remove barriers to accessing programs and services. Some challenges to harm reduction include community resistance, working with marginalized groups, ensuring proper training, and adequate resources.