Cognitive-behavioral therapy (CBT) treats depression by challenging irrational thoughts and replacing them with more rational beliefs. CBT focuses on changing maladaptive thoughts and behaviors through Ellis' ABC model, which disputes thoughts and encourages clients to engage in pleasurable activities. Studies found CBT has around a 90% success rate but requires considerable effort from clients and may not work for those with rigidly irrational beliefs. CBT works best when combined with medication as clients can target both the causes and symptoms of depression. The principles of CBT also benefit sports teams by challenging unhelpful attitudes like a "must win" mentality.