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Core Services


We can provide expert witness for victims of trauma and human rights abuses for UK, Asylum Tribunals and International Courts



Our London based Clinical Psychologists can assist with a variety needs. We utilise evidenced based psychological therapies such as CBT. 

Click here to make an appointment with a Clinical Psychologist today at our Clinic in Clapham, London, UK

We are BUPA Approved.



Recent training includes:


Trauma and psychosis

Working on Death Row

Psychological care for refugees



Criterion A Psychology Services was established to meet demand for experienced clinical psychologists to provide services to people around the world who have been or are involved with traumatic events. We provide expert witness, training and consultation and treatment.

We operate by having a bank of staff who are recruited for specific projects as well as core contracted staff.

Criterion A Psychology Services was created by Dr. Brock Chisholm. Dr. Chisholm has extensive experience in working with victims of trauma. He has provided expert witness to several high profile cases and has provided evidence based psychological intervention to many people suffering complex reactions to traumatic events. He is trained in EMDR, Cognitive Behaviour Therapy and Narrative Exposure Therapy.

Individual psychological therapy is not sufficient for many survivor’s of trauma. That is why Criterion A provides a comprehensive service and treatment packages for complicated traumatic stress reactions.

Dr. Brock Chisholm is on the list of experts for the Preventing Sexual Violence Initiative hosted by The Stabilisation Unit under the British Foreign and Commonwealth Office. The initiative was created by UK Foreign Secretary William Hague.

Why Criterion A? Criterion A refers to the traumatic event that can elicit a PTSD reaction. We specialise in providing solutions to people affected by traumatic events. 


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