Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Imperial College London, London, United Kingdom; Translational Psychiatry Research Group, Research Department of Mental Health Neuroscience, Division of Psychiatry, UCL Institute of Mental Health, University College London, London, United Kingdom; Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, United Kingdom; Clinical Psychopharmacology Unit, Research Department of Clinical, Educational and Health Psychology, University College London, London, United Kingdom; NIHR University College London Hospitals Biomedical Research Centre, London, United Kingdom; The Traumatic Stress Clinic, St Pancras Hospital, Camden and Islington NHS Foundation Trust, London, United Kingdom; National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, United Kingdom
Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Imperial College London, London, United Kingdom; Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, United Kingdom
Matthew Kempton
Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, United Kingdom
Tom P Freeman
Translational Psychiatry Research Group, Research Department of Mental Health Neuroscience, Division of Psychiatry, UCL Institute of Mental Health, University College London, London, United Kingdom; Clinical Psychopharmacology Unit, Research Department of Clinical, Educational and Health Psychology, University College London, London, United Kingdom; Department of Psychology, University of Bath, Bath, United Kingdom
Oliver Howes
Psychiatric Imaging Group, MRC London Institute of Medical Sciences, Imperial College London, London, United Kingdom; Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, United Kingdom
Chronic psychosocial adversity induces vulnerability to mental illnesses. Animal studies demonstrate that this may be mediated by dopaminergic dysfunction. We therefore investigated whether long-term exposure to psychosocial adversity was associated with dopamine dysfunction and its relationship to psychological and physiological responses to acute stress. Using 3,4-dihydroxy-6-[18F]-fluoro-l-phenylalanine ([18F]-DOPA) positron emission tomography (PET), we compared dopamine synthesis capacity in n = 17 human participants with high cumulative exposure to psychosocial adversity with n = 17 age- and sex-matched participants with low cumulative exposure. The PET scan took place 2 hr after the induction of acute psychosocial stress using the Montréal Imaging Stress Task to induce acute psychosocial stress. We found that dopamine synthesis correlated with subjective threat and physiological response to acute psychosocial stress in the low exposure group. Long-term exposure to psychosocial adversity was associated with dampened striatal dopaminergic function (p=0.03, d = 0.80) and that psychosocial adversity blunted physiological yet potentiated subjective responses to acute psychosocial stress. Future studies should investigate the roles of these changes in vulnerability to mental illnesses.
