Findings from a recent online survey suggest that the idea of the heart containing the very “essence” of a person might be more than just a spiritual concept, with nearly 90% of organ recipients saying they had experienced personality changes after transplant surgery, no matter the organ they received.
Ever since the first human heart transplants in 1967, patients have reported, often reluctantly, some odd and inexplicable changes to their personalities, several reporting they feel less like themselves and more like their donor. In one case, a transplant recipient reported suddenly developing a love for music after receiving the heart of a young male musician.
Other transplant recipients say they developed new tastes for food, art, sex, or careers after their surgeries.
Now, a study from the University of Colorado (CU) suggests it’s not just heart transplants that appear to trigger such fundamental changes to personhood.
Of 23 heart recipients and 24 other organ recipients, almost 90% said they experienced four or more personality changes, and that most of these changes had to do with temperament, emotions, food, identity, religious/spiritual beliefs, or memories.
While the study is too small to be statistically significant, medical researcher Brian Carter and his colleagues at CU conclude that “heart transplant recipients may not be unique in their experience of personality changes after transplantation”.
They said such changes may occur after the transplantation of any organ, and the subjects demands further research.
The study is one of the first to quantify the personality changes that occur after a wide variety of organ transplants. Previous studies have tended to focus on heart transplants, as these anecdotes are thought to be the most extreme and long-lasting.
In the case of liver or kidney transplants, patients in previous studies tend to report changing feelings of stress, anxiety, depression, or other mental health issues.
Some researchers have explained these differences by arguing there is “a little brain in the heart”. These potential explanations, however, do not consider transplanted organs other than the heart.
In those cases, perhaps immunosuppressive drugs are to blame for personality changes. Or maybe “memories” are stored widely throughout the body, not just in a few crucial organs.
The “systemic memory hypothesis” predicts that all living cells possess memory, and that a transplant recipient can sense a donor’s history through their tissue.
Although a transplant organ’s nerve connections are severed, nerves may still function within the organ. Some evidence suggests nerve connections may be partially restored a year after transplant surgery.
Neurotransmitter interactions based on donor memories might then cause a physiological response to the recipient’s nervous system that impacts their personality.
Scientists have found the cells of donors circulating in recipients as many as two years after a transplant. Where those cells go and what happens to their DNA is unclear. The DNA, once escaped from cells, does appear to trigger inflammation, and chronic, low-grade inflammation has been shown to alter personality traits.
If personality changes are really as common and widespread as the small study from CU suggests, then further research is desperately needed. In 2022, there were more than 150 000 organ transplants conducted worldwide.
The study was published in Transplantology.
Study details
Personality Changes Associated with Organ Transplants
Published in Transplantology on 17 January 2024
Abstract
Personality changes have been reported following organ transplantation. Most commonly, such changes have been described among heart transplant recipients. We set out to examine whether personality changes occur following organ transplantation, and specifically, what types of changes occur among heart transplant recipients compared to other organ recipients. A cross-sectional study was conducted in which 47 participants (23 heart recipients and 24 other organ recipients) completed an online survey. In this study, 89% of all transplant recipients reported personality changes after undergoing transplant surgery, which was similar for heart and other organ recipients. The only personality change that differed between heart and other organ recipients and that achieved statistical significance was a change in physical attributes. Differences in other types of personality changes were observed between these groups but the number of participants in each group was too small to achieve statistical significance. Overall, the similarities between the two groups suggest heart transplant recipients may not be unique in their experience of personality changes following transplantation, but instead such changes may occur after the transplantation of any organ. With the exception of physical attributes, the types of personality changes reported were similar between the two groups. These finding indicate that heart transplant recipients are not unique in their reported experience of personality changes following organ transplantation. Further studies are needed to deepen our understanding of what causes these personality changes.
Transplantology article – Personality Changes Associated with Organ Transplants (Open access)
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