This book presents, at a non-technical level, several approaches for the analysis of correlated data: mixed models for continuous and categorical outcomes, nonparametric methods for repeated measures and growth mixture models for heterogeneous trajectories over time. "This is a comprehensive text describing a wide-range of statistical techniques, from basic to advanced, applicable to data generated from the field of Mental Health research. The field of Psychiatry is one of the very core subjects of Mental Health, along with Clinical Psychology and Psychiatric SocialWork. Hence, it is in fact an amalgamation of many cross linking fields of the social sciences. Therefore, coming out with a book that addresses various dimensions of science is a remarkable achievement. ? [T]he book has three unique selling points - addressing the issues of the different natures of data in psychiatry, post hoc analyses and adjustments for multiple comparisons, and study design and sample size determination. ? I very strongly advocate that researchers/academics have this book with them or in their library."-Chandra Bhushan Tripathi, in ISCB News, December 2018"This book will reach a wide audience since it gives a non-technical and comprehensible introduction for non-experts to a complicated topic, with a series of worked-through examples, while at the same time it provides the applied statistician with thorough guidance to the analysis of longitudinal data, in the traditional normal distribution setting as well as for non-normal distributions (binary, Poisson etc.). It also contains insightful discussions on more advanced topics, with good references for further reading. The book stands out in the discussion on multiple testing, with good advice in a jungle of possibilities and in the handling of missing values (a comprehensible explanation of the problems and pitfalls, together with a sober guidance to avoiding such pitfalls in various circumstances). Also, the section on causality is probably the best I ever came across.The guidance and summary sections at the end of each chapter will serve as a reminder on the important hints for this particular topic. An extremely nice addition to the book is the accompanying ho