The textbook "Psychopharmacogenetics" offers a comprehensive analysis of the psychopharmacological treatment of psychiatric disorders in adults and children. It highlights the challenges associated with the treatment of mood disorders, psychoses, substance abuse, and dementia. Despite the availability of treatment options, satisfaction with these therapies remains low, attributed to various factors, including insufficient understanding of the underlying mechanisms and the heterogeneity of the disorders. The book discusses the need to develop new approaches that allow for better prediction of the efficacy and tolerability of treatments. Given the high costs associated with psychiatric disorders, the importance of psychopharmacogenetics is emphasized to optimize the selection of the most suitable therapy and minimize economic impacts.