As our world becomes increasingly uncertain, mental health issues have increased dramatically, and the need for accessible, effective treatment has never been greater. This flagship acceptance and commitment therapy (ACT) workbook outlines a comprehensive set of core skills to help readers build resilience in the face of uncertainty, and heal the psychological and emotional pain keeping them from living a meaningful, fulfilling life. Whether it's anxiety, sadness, anger, numbness, or grief, readers can rely on ACT to provide genuine and lasting relief.