Achshually, CBT is for people that generally have their full mental capacities because it requires them to consciously and directly focus on their thoughts, emotions, and behaviors. The cognitive part in particular requires certain mental abilities. Some mental incapacities prevent this type of cognitive introspection, so those individuals would benefit more from therapies that are more indirect in nature, such as ones that fall under the psychodynamic umbrella, acceptance & commitment, values-oriented, solution-focused, or skills training.