For decades, medicine has been dominated by a "fix-it-when-it-breaks" mentality. We wait for disease to appear, then react. But when the machinery in question is the only body you'll ever have, waiting until failure is both risky and costly. A better way forward, what I call healthspan medicine, is proactive, preventive, and personal. The Intersection of Psychology and Biology Healthspan medicine blends advances in diagnostics, geroscience, systems biology, and artificial intelligence with a clear-eyed recognition that our biology is deeply influenced by our psychology.