"Professional incompetence" means lack of ability to practice psychology safely and skillfully arising from:
1. Lack of knowledge or training;
2. Impaired physical or mental ability; or
3. Dependence upon an alcoholic beverage as defined in NRS 202.015 or any controlled substance.
(Added to NRS by 1985, 1906; A 1987, 483, 1570, 1577)