The article reviews the current state of animal models for mental illnesses, focusing on schizophrenia, depression, and bipolar disorder. It highlights the challenges in creating useful models due to the subjective nature of symptoms, lack of biomarkers, and incomplete understanding of neurobiology and genetics. The authors argue for areas of focus to improve model development and provide guidelines for reporting animal models. They emphasize the importance of construct, face, and predictive validity in evaluating models. For schizophrenia, they discuss genetic and environmental models, noting the limitations of common genetic variants and environmental factors. For depression, they critique traditional behavioral tests and suggest focusing on anhedonia and homeostatic symptoms. For bipolar disorder, they highlight the difficulty in modeling manic episodes and the need for broader behavioral assays. The authors conclude that while animal models are challenging, they are essential for advancing our understanding of neuropsychiatric disorders and developing new treatments.The article reviews the current state of animal models for mental illnesses, focusing on schizophrenia, depression, and bipolar disorder. It highlights the challenges in creating useful models due to the subjective nature of symptoms, lack of biomarkers, and incomplete understanding of neurobiology and genetics. The authors argue for areas of focus to improve model development and provide guidelines for reporting animal models. They emphasize the importance of construct, face, and predictive validity in evaluating models. For schizophrenia, they discuss genetic and environmental models, noting the limitations of common genetic variants and environmental factors. For depression, they critique traditional behavioral tests and suggest focusing on anhedonia and homeostatic symptoms. For bipolar disorder, they highlight the difficulty in modeling manic episodes and the need for broader behavioral assays. The authors conclude that while animal models are challenging, they are essential for advancing our understanding of neuropsychiatric disorders and developing new treatments.