Weakness of custodial sentencing?

-Doesn't include the number of inmates experiencing mental health problems before they were incarcerated. -Significnat because many of those convicted may have pre-exisiting psychological and emotional difficulties at the time they were convicted -Prisoners may be importing their own pre-exisiting conditions with them into the prison, increasing the likelihood of the suicide rates showing that prison, therefore, prison is not causing psychosis as it is a predisposition. -Suggesting that there may be confounding variables that links prisons and negative psychological.