Large-scale genetic analysis has transformed our understanding of human health and diseases. Over the past decade, disease-enriched cohorts have empowered genome-wide association studies to identify DNA sequence variants underlying complex traits and diseases. More recently, the emergence of biobanks that contain a rich spectrum of phenotypic information provides an unparalleled opportunity for biomedical research toward the realization of precision medicine. Through the lenses of statistical and population genetics, I will present the work I undertook under these two paradigms to study the contribution of common and rare genetic variation to neuropsychiatric traits, to investigate the genetic architecture of age of onset for complex traits beyond disease susceptibility, as well as to improve polygenic risk prediction models within and across human populations. In closing, I will highlight some of the opportunities and challenges for genetic studies in Taiwan and globally and their translational impact.