The Theory of Problem-Solving Behaviour is a non-routine activity aimed at altering an undesirable state. It helps consultant psychologists identify and solve problems in various domains such as sports, education, and healthcare. The theory can be applied to evaluate the current state of a problem, identify central ideas, and develop effective intervention strategies. By using this theory, consultant psychologists can overcome challenges and ethical dilemmas that hinder their decision-making process, ultimately providing more effective psychological consulting services.