The Ian Anderson murder trial has heard he most likely has a personality disorder, which has shaped behaviour throughout his life.

Dr Puri, a forensic psychiatrist, was called as an expert witness by the defence at Douglas Courthouse this afternoon.

Mr Anderson denies murdering 60-year-old Ballabeg man Neil Roberts in late 2013.

Dr Puri interviewed Ian Anderson for eight hours in custody last year, and told the court Mr Anderson had ingrained traits, established during childhood, which have manifested themselves in later life.

He said patterns of behaviour were also impulsive at times and took no heed of possible consequences.

Dr Puri said Mr Anderson's sense of self was fragmented, and there were signs of 'maladaptive coping strategies', saying Mr Anderson had a 'less than robust personality'.

Dr Puri is due to continue giving evidence at Douglas courthouse tomorrow, from 10am.