There was a case similar to this a year or so ago, the judge in that case was said to have stated she could't use her schizophrenia as an excuse for what she had done :/
'At Edgington's trial the prosecution argued she had been wrongly diagnosed with schizophrenia and had a borderline personality disorder rather than a mental illness.
The judge, Brian Barker, told Edgington her acts had been "consistent and calculated". He said: "You are manipulative and exceptionally dangerous. What you did could not have been more selfish. I disagree that the responsibility for these acts can be laid on others. You made your choice and these were terrible acts for which you must take responsibility."
http://www.theguardian.com/uk/2013/m...cola-edgington