I was under the impression the psychiatrist in question had never met Bamber, but was an armchair diagnostician.
I have no idea of the authenticity of what happened as it is in Wilkes book and quoted without sources. ( it may be listed as sourced elsewhere )
I don't know why they even called a psychiatrist for him. His mantra was " Im an Innocent man who has lost my family " He was claiming total innocence. This was pre trial.