(1) Physical, mental, or emotional diseases related to mental stress arising out of and in the course of employment shall be compensable under this chapter only when there is a sufficient legal and medical causal connection between the employee's disease and employment.

(2) (a) Legal causation requires proof of extraordinary mental stress arising predominantly and directly from employment. (b) The extraordinary nature of the alleged mental stress is judged according to an objective standard in comparison with contemporary national employment and nonemployment life.

(a) Legal causation requires proof of extraordinary mental stress arising predominantly and directly from employment.

(b) The extraordinary nature of the alleged mental stress is judged according to an objective standard in comparison with contemporary national employment and nonemployment life.

(3) Medical causation requires proof that the physical, mental, or emotional disease was medically caused by the mental stress that is the legal cause of the physical, mental, or emotional disease.

(4) Good faith employer personnel actions including disciplinary actions, work evaluations, job transfers, layoffs, demotions, promotions, terminations, or retirements, may not form the basis of compensable mental stress claims under this chapter.

(5) Alleged discrimination, harassment, or unfair labor practices otherwise actionable at law may not form the basis of compensable mental stress claims under this chapter.

(6) An employee who alleges a compensable occupational disease involving mental stress bears the burden of proof to establish legal and medical causation by a preponderance of the evidence.