Dr John Potokar
Consultant Senior Lecturer in Psychiatry 
Academic Unit of Psychiatry
Oafield House
Oakfield Grove
Clifton
Bristol, BS8 2BN
Phone: + 44 (0)117 33 13356
Fax: + 44 (0)117 33 14026
Email: john.potokar@bristol.ac.uk
Secretary: Janet Hickling
Phone: 0117 33 14010
Fax: 0117 33 14026
Email: j.hickling@bristol.ac.uk
Research Interests
Stress is ubiquitous and the way that our body, brain and mind responds depends on many factors such as anthropological drives, genes, early experience, previous exposure etc. Sometimes our stress response systems become overwhelmed resulting in changes in behaviour e.g. depression or sickness behaviour. Causes include bereavement, divorce, unemployment, viral illness, chronic inflammation etc. I work clinically as a Liaison Psychiatrist at the Bristol Royal Infirmary and the aims of my group are to better understand the effects of chronic illness on stress responses especially with respect to the neurotransmitter serotonin (5-HT). We focus on 5-HT because a large body of research emphasises its role in mediating appetitive drives and behaviour that become disturbed when stress responses are overwhelmed. Serotonergic medication is used to treat depression and is increasingly being used in the medically unwell and as such we are also interested in the effects of treatment on stress responses and 5-HT function. Research paradigms we use include tryptophan depletion, dietary manipulation, CO2 challenge studies, sleep studies and much more. It is a fascinating and extremely clinically relevant area to explore and we feel privileged to be doing so! If you are interested in finding out more please contact me (John.Potokar@bristol.ac.uk).
Selected Publications
Simon JC Davies, Peter R Jackson, Glyn Lewis, David J Nutt, John Potokar Autonomic dysfunction – the link between hypertension and panic? (2008) J Affective Disorders 2008 Dec;111(2-3):344-50
Shufflebotham J, Wetherell MA, Hince D, Hood S, Lightman S, Nutt D, Probert C, Potokar J. Women with diarrhoea-predominant irritable bowel syndrome show an increased pressure response to 35% carbon dioxide stress challenge. Stress 2009;12(1):30-6.
Bell C, Hood S, Potokar J, Nash J, Adrover M, Frampton C, Hince D, Rich A, Argyropoulos S, Nutt D Rapid tryptophan depletion following cognitive behavioural therapy for panic disorder Psychopharmacology October 13th 2009 Epub ahead of print
Lindsey I. Sinclair,David M. Christmas,Sean D. Hood, John P. Potokar, Andrea Robertson, Andrew Isaac, Shrikant Srivastava, David J. Nutt, and Simon J. C. Davies Antidepressant-induced jitteriness/anxiety syndrome: systematic review. British Journal Psychiatry 2009 Jun;194(6):483-90.
Hood SD, Hince DA, Davies SJC, Argyropoulos S, Robinson H, Potokar J, Nutt DJ Effects of acute tryptophan depletion in serotonin reuptake inhibitor – remitted patients with generalized anxiety disorder Psychopharmacology 2010 Feb;208(2):223-32
Christmas, D, Badawy, A. Hince, D. Davies, S.J.C Probert, C.Creed, T. Smithson, J. Afzal, M. Nutt, D. Potokar, J.P. Increased serum free-tryptophan in patients with diarrhea-predominant irritable bowel syndrome Nutrition Research 30 (2010) 678–688
Seddon K, Bailey J, Morris K, Bettica P, Rich A, Potokar J, Nutt D 7.5% CO2 responses in patients with Generalised Anxiety Disorder J Psychopharmacology 2011 Jan;25(1):43-51
Simon Davies, John Potokar and David ChristmasA biological pathway linking inflammation and depression: activation of indoleamine 2,3-ioxygenase Neuropsychiatric Disease and Treatment 2011:7 431-439.