This book discusses how the radical psychosocial changes during the COVID-19 pandemic may impact neurodevelopment from birth through the transition to early adulthood, thereby altering the trajectory of psychological, social, and academic development in the years to come. The COVID-19 pandemic caused worldwide and sustained educational and psychosocial disruption for children and adolescents. Schools, when they were able to remain open, quickly shifted to adopt untested virtual instruction methods that varied widely in implementation. Youth were exposed to increased stress at home, including adverse childhood experiences (ACEs), and mental health conditions increased. Young children who needed support for developmental and learning delays, as well as disabilities, missed critical interventions and/or entered school later. Older adolescents were lost entirely from the educational system. Although the acute phase of the pandemic has passed, the significant developmental and psychosocial impact on this generation of young people will be felt for decades to come, especially as resources have not yet been allocated in a manner that effectively and aggressively intervenes on behalf of those most impacted. Academic achievement data has shown significant attenuation in math and reading gains. The mental health system is presently unable to meet the demands of the population, prompting prominent national health care provider associations and other experts to declare a state of emergency for youth mental health. There are significant implications of changes in academic achievement for the identification of disability using pre-pandemic methods, especially for the fields of forensic neuropsychology and special education law. Radical educational and psychosocial changes during the COVID-19 pandemic may impact neurodevelopment from birth through the transition to early adulthood, with lasting impacts on psychological and social functioning, as well as academic achievement, especially for vulnerable youth. Altered Trajectories shows how the lessons of the COVID-19 pandemic have the potential to be a catalyst for change. In a world that anticipates future sudden and calamitous psychosocial disruption due to climate change or new pandemics, the information within this book is expected to be of use both in the immediate term and the future. This information has the potential to shape progress in the fields of psychology, developmental neuroscience, sociology, public policy, and the law.