Our People
Criterion A is the part of the diagnosis for PTSD that refers to the traumatic event that triggers the reaction. Criterion A Psychology provides services to people following traumatic events. We are a flexible company designed to meet complex needs.
Leadership Team
Dr Brock Chisholm
Dr Brock Chisholm
Director of Clinical Services
Dr Brock Chisholm is a Consultant Clinical Psychologist and Director of CAPS. He is the former Clinical Lead of the UK Psychological Trauma Society and former Trustee of Survivors UK.
Dr Brock Chisholm is an extremely knowledgeable Consultant Clinical Psychologist with a degree in Psychology, Masters in Psychological Research Methods and Doctorate of Clinical Psychology who previously been employed in specialist NHS PTSD services and has 20 years of specialist clinical experience.
Dr Chisholm works collaboratively and compassionately, using evidence based psychological interventions such as CBT to assist people in making emotional and behavioural changes and improve well-being. He cultivates a therapeutic space where people experience being genuinely heard and understood.
Dr Chisholm has particular expertise in assisting people who have experienced events such as sexual & physical assaults, accidents, bereavements, domestic violence and traumatic childhoods, as well as adjustments to life events such as bullying or relationship difficulties. Dr Chisholm treats post traumatic stress disorder (PTSD), anxiety, low mood, depression, phobias, and adjustment difficulties and with people experiencing psychosis and the overlap between trauma and psychosis.
Dr Chisholm also has provided expert witness in several high profile cases in the UK and International courts. for criminal and civil matters in Specialist Immigration, and Asylum Court, Court of Appeal, Supreme Court, the European Court of Human Rights, the Baha Mousa Public Inquiry, the African Court of Justice, Military Courts Martial and The United Nations. He has acted in terrorism, police, rendition, serious fraud, trafficking, war crimes, torture, and many other matters nationally and internationally. In HS (Uganda), R (on the application of) v Secretary of State for the Home Department [2012] EWCA Civ 94 Lady Justice Rafferty says ‘it seems to me that the authority and depth of Dr Chisholm's report arguably changes the landscape of the appellant's claim.’
He was previously retained by the American Civil Liberties Union (ACLU) as expert witness in a case litigating against alleged torture at CIA run black sites.
Psychological Expert Witnesses
Dr Sarah Whittaker-Howe
Dr Sarah Whittaker-Howe
Chartered Clinical Psychologist
Dr. Sarah Whittaker-Howe, Clinical Psychologist, is expert in the psychological consequences and recovery from organised violence and human right abuses as well as in veteran mental health and with survivors of sexual violence. She has considerable experience both within the NHS and charitable sectors providing psychological interventions to those suffering complex trauma reactions, including survivors of torture, sexual violence, and combat. She was previously worked at The Havens Sexual Assault Referral Centres; The Forced Migration Trauma Service and Combat Stress.
Sarah has a strong commitment to non-profit organisations working within conflict areas. She partners with several organisations in the Middle East and Africa, providing consultation, training, and developing programmes that address the mental health needs of war affected communities and refugee populations. She also provides expert witness for criminal investigations, asylum tribunals and international courts.
Dr Jonathan Buhagiar
Clinical Psychologist
Dr Jonathan Buhagiar is a Clinical Psychologist and Systemic Psychotherapist. He works with individuals, couples and families and has expertise with a wide range of challenges that can impact people's lives (e.g. anxiety, low mood/depression, bereavement, confidence/self-esteem, workplace stress, communication and relationship issues, life transitions etc).
He also has particular experience of supporting with traumatic experiences and with psychosis, having worked in post-traumatic stress services and he was the co-lead for an NHS Early Intervention in Psychosis Psychology Service.
Jonathan works collaboratively and sensitively with particular attention to the person's values and identities, helping to make sense of the person's difficulties and to find ways forwards. He has specialism in a range of evidence-based therapies, such as cognitive behavioural therapy, systemic therapies (e.g. narrative therapy, family therapy approaches) and trauma-informed and focussed therapies.
He brings national and international experience of delivering training and developing capacity with frontline staff in statutory, community and non-governmental organisations. He offers organisational consultancy and has a particular interest in helping teams and services develop trauma-informed practices and policies that support staff members and organisations in the day-to-day delivery of care.
Dr Jonathan Buhagiar
Dr. Rebecca O’Grady
Dr. Rebecca O’Grady
Clinical Psychologist
Dr Rebecca O’Grady is a Clinical Psychologist with specialist knowledge and experience in working with complex trauma, complex emotional needs, and people subject to multiple layers of disadvantage in their lives, including those affected by substance use, homelessness and forced displacement. She has worked extensively with refugees and asylum seekers. She provides direct therapeutic interventions, clinical supervision, and supports staff teams to understand and work with complex mental health presentations.
Rebecca has over a decade of experience working within specialist services across the NHS and third sector, providing evidence-based psychological interventions for PTSD, Complex PTSD and the effects of prolonged trauma. She has worked across the full range of mental health presentations, including depression, anxiety and psychosis symptoms. This has included working with additional complexities and barriers to accessing support. Rebecca is reflective and thoughtful in her approach and attentive to cultural differences. She draws primarily on Mentalisation-Based Therapy, systemic/narrative approaches and trauma-focused models (EMDR, NET & Imagery Rescripting).
Rebecca has held senior clinical leadership roles within services, developed trauma-informed training for voluntary sector organisations, and is currently working as the Associate Lead for Mentalisation-Based Therapy for people with complex emotional needs within the NHS. Rebecca has worked as an Expert Witness in asylum court cases since 2018.
Country Expert Witnesses
Dr. Ayesha Ahmad
Dr. Ayesha Ahmad
Role
Dr. Ayesha Ahmad is a country expert for mental health and associated stigmas, human rights violations, gender-based and honour violence towards both men and women, female genital mutilation, paediatric humanitarian health, trafficking, and conflict-related harms. Her countries of representation are Afghanistan, Pakistan, India, Iran, Iraq, Sierra Leone, Nigeria, Ghana, Eritrea and Ethiopia. Dr. Ahmad has extensive expertise as an expert witness. She has and provided written and oral evidence and provided expert evidence for AS (Safety of Kabul).
Dr. Ayesha Ahmad is a Reader/Associate Professor in Global Health Humanities; St. George’s University of London and a medical ethicist with significant international experience as an academic lecturer and researcher in global health who specialises in is mental health and psychological trauma in conflict settings. Especially with survivors of gender-based violence. Her academic research focuses on cross-cultural mental health.
She is an executive committee member for the Transcultural Special Interest Group at the Royal College of Psychiatrists, United Kingdom and a member of the Clinical Ethics Committees at St. George’s Hospital and Great Ormond Street Hospital for children, London, United Kingdom.
Dr Rodney Reynolds
Dr Rodney Reynolds
Role
Dr Rodney Reynolds is a medical anthropologist. He is a country expert on mental health in regions of Central America, South America, Caribbean, and Sub-Saharan Africa. His expertise is on mental health and human rights violations.
He is a board member for a U.S based non-governmental organization providing assistance to migrants who have fled armed conflict, gang violence, trafficking, and modern slavery. He has given expert witness including country reports for men with severe mental disorder facing deportation to Jamaica from the United Kingdom.
Psychological Therapy
Dr Sarah Whittaker-Howe
Dr Sarah Whittaker-Howe
Chartered Clinical Psychologist
Dr. Sarah Whittaker-Howe, Clinical Psychologist, is expert in the psychological consequences and recovery from organised violence and human right abuses as well as in veteran mental health and with survivors of sexual violence. She has considerable experience both within the NHS and charitable sectors providing psychological interventions to those suffering complex trauma reactions, including survivors of torture, sexual violence, and combat. She was previously worked at The Havens Sexual Assault Referral Centres; The Forced Migration Trauma Service and Combat Stress.
Sarah has a strong commitment to non-profit organisations working within conflict areas. She partners with several organisations in the Middle East and Africa, providing consultation, training, and developing programmes that address the mental health needs of war affected communities and refugee populations. She also provides expert witness for criminal investigations, asylum tribunals and international courts.
Dr Jonathan Buhagiar
Dr Jonathan Buhagiar
Clinical Psychologist
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Dr. Rebecca O’Grady
Dr. Rebecca O’Grady
Clinical Psychologist
Dr Rebecca O’Grady is a Clinical Psychologist with specialist knowledge and experience in working with complex trauma, complex emotional needs, and people subject to multiple layers of disadvantage in their lives, including those affected by substance use, homelessness and forced displacement. She has worked extensively with refugees and asylum seekers. She provides direct therapeutic interventions, clinical supervision, and supports staff teams to understand and work with complex mental health presentations.
Rebecca has over a decade of experience working within specialist services across the NHS and third sector, providing evidence-based psychological interventions for PTSD, Complex PTSD and the effects of prolonged trauma. She has worked across the full range of mental health presentations, including depression, anxiety and psychosis symptoms. This has included working with additional complexities and barriers to accessing support. Rebecca is reflective and thoughtful in her approach and attentive to cultural differences. She draws primarily on Mentalisation-Based Therapy, systemic/narrative approaches and trauma-focused models (EMDR, NET & Imagery Rescripting).
Rebecca has held senior clinical leadership roles within services, developed trauma-informed training for voluntary sector organisations, and is currently working as the Associate Lead for Mentalisation-Based Therapy for people with complex emotional needs within the NHS. Rebecca has worked as an Expert Witness in asylum court cases since 2018.
Employment opportunities
We are pleased to announce exciting opportunities for clinical psychologists with experience in the assessment and treatment of survivors of traumatic events. Consultants are not employees.
Please contact us with your CV if you would be interested in working with us.