Perfectionism involves setting unreasonably high standards or expectations that are difficult or impossible to meet. Although many people strive to do well, the excessive standards involved in perfectionism can interfere with people's lives and effective functioning. Perfectionistic thinking is often excessive and rigid, and perfectionistic beliefs lead to behaviors that can be harmful (excessively washing hands to avoid contamination) or time-consuming (spending long hours reviewing and checking school assignments in an attempt to get perfect grades). Because perfectionistic standards are difficult to achieve, people who suffer from perfectionism may avoid situations that trigger the need to be perfect or procrastinate starting important tasks. Perfectionism can be associated with other problems, such as anxiety, depression, and interpersonal difficulties.

Cognitive-behavior therapy can help a person identify perfectionistic thoughts and behaviors, and understand the role that perfectionism plays in their mood, functioning, and relationships. Therapy helps a person understand the costs of holding themselves (and others) to excessive and unrealistic standards. Treatment can help those who struggle with perfectionism develop more helpful and balanced thinking about goals and expectations while decreasing perfectionistic behaviors. As they make these changes, people test their beliefs about perfectionism and learn that perfectionistic behaviors are not necessary and can even be detrimental. In this way, they can develop more helpful standards, change their behavior, and decrease distress about imperfection.