The adrenochrome investigations into schizophrenia which I have pursued since 1952 and the recent important investigations into the relationship between heart function and (adrenalin —> adrenochrome) points to a connection between brain and cardiac disorder. I suggest there is a link between schizophrenia and some types of heart dysfunction. My hypothesis is that the biochemistry of schizophrenia has evolved as a protection against death from cardiac fibrillation during severe stress, but for one to two percent of the population that life saving mechanism has gone too far, it leads to schizophrenia. The evidence for this idea has been forming slowly over the past 40 years, and is an outcome of the adrenochrome hypothesis of schizophrenia proposed by my colleague, Dr. H. Osmond, and me.