"I Had a Black Dog" is an insightful non-fiction book by Matthew Johnstone that addresses the challenges of mental health. In this work, the concept of the "black dog" is used as a metaphor for depression and other mental illnesses. Johnstone, an experienced author and illustrator, employs his creative skills to present complex topics in an accessible and understandable way. The book is not only informative but also visually appealing, making it a valuable tool for anyone looking to learn more about mental health. It offers insights and perspectives that can help both those affected and their loved ones better understand and cope with the issues at hand. With just 48 pages, it is a compact yet powerful work that provokes thought and encourages discussion about mental health.