Brain disorders, from neurodegenerative to psychiatric disorders, are among the most challenging conditions to study because of the intricate nature of the human brain and the limitations of existing model systems in recapitulating all these intricacies. However, innovations in stem cell technologies now allow us to reprogram patient somatic cells to induced pluripotent stem cells (iPSCs), which can then be differentiated to disease-relevant neural and glial cells. iPSCs are a valuable tool to model brain disorders, as they can be derived from patients with known symptom histories, genetics, and drug-response profiles. Here, we discuss the premise and validity of the iPSC-based in vitro model system and highlight key findings from the most commonly studied neurodegenerative and psychiatric disorders.N europsychiatric and neurodegenerative disorders constitute a bulk of brain disorders, contributing significantly to the global burden of disease. The uniquely human abilities of higherorder thought, symbolic abstract thought, and the ability to generate and share complex ideas emerged along with a large brain. Disorders of the brain are therefore challenging to study as no single model system fully encapsulates the complexity of the human brain, one of the least accessible organs within the body. While postmortem data can provide information regarding the end-stage pathology of a disease, its causes and consequences remain difficult to parse. While animal models provide a complex and live system that enables us to study specific endophenotypes of disorders, they do not fully recapitulate the complex human-specific pathology. Therefore, more model systems are required.