This episode explores the potential of using brain scans, specifically fMRI, to diagnose mental illnesses like depression, and questions the implications of such technology. The discussion begins with the premise of diagnosing depression through brain scans, similar to identifying a broken arm via X-ray, featuring insights from Nobel laureate Eric Kandel on the emerging field of photographic diagnosis of mental illness. Against the backdrop of fMRI technology, which measures brain activity by detecting blood flow, psychiatrist Cynthia Fu details a study where machine learning algorithms accurately diagnosed depression in patients based on their brain scans while viewing faces. However, the conversation shifts to a cautionary tale about the history of SIDS research, where flawed assumptions about enlarged thymus glands led to harmful radiation treatments, highlighting how societal factors like poverty can skew medical understanding. More significantly, this historical example raises concerns about the potential for similar errors in current medical research, particularly in interpreting brain scans. The hosts debate whether mental illness can be objectively diagnosed through technology, or if the ambiguity of human experience makes it too complex. Despite advancements in brain imaging, the episode concludes that current technology isn't reliable enough for clinical use, underscoring the importance of treating patients as individuals and acknowledging the limitations of science in fully understanding mental health.