(1) An adult, or a minor under eighteen (18) years of age who may be tried as an adult, convicted of a crime and subject to sentencing, is referred to in this section and KRS 532.135 and 532.140 as a defendant.
(2) A defendant with significant subaverage intellectual functioning existing concurrently with substantial deficits in adaptive behavior and manifested during the developmental period is referred to in KRS 532.135 and 532.140 as a defendant with a serious intellectual disability. "Significantly subaverage general intellectual functioning" is defined as an intelligence quotient (I.Q.) of seventy (70) or below.
(3) A defendant is referred to in KRS 532.135 and 532.140 as a defendant with serious mental illness if:
(a) At the time of the offense, he or she has active symptoms and a documented history, including a diagnosis, of one (1) or more of the following mental disorders using the most recent edition of the Diagnostic and Statistical Manual of Mental Disorders published by the American Psychiatric Association:
1. Schizophrenia;
2. Schizoaffective disorder;
3. Bipolar disorder; or 4. Delusional disorder; and (b) The disorder is not manifested primarily by repeated criminal conduct or attributable solely to the acute effects of the voluntary use of alcohol or other drugs. As used in this subsection, a documented history and diagnosis shall be from a mental health professional as defined in KRS 645.020(7)(a) to (d).