Final answer:
Approximately 60-90% of empirically supported treatments are cognitive behavioral, which is evidenced by multiple meta-analyses and studies confirming its effectiveness across various mental health issues.
Step-by-step explanation:
Approximately 60-90% of empirically supported treatments are cognitive behavioral. Cognitive-behavioral therapy (CBT) is a widely accepted form of psychological treatment that has been shown to be effective for a variety of mental health issues. This form of therapy focuses on identifying and changing negative thought patterns and behaviors that contribute to psychological distress.
Studies, such as those by Butler et al. (2006) and Chambless & Ollendick (2001), have conducted meta-analyses that demonstrate the empirical status and effectiveness of CBT. Moreover, randomized controlled trials like the one by Jacobs et al. (2004) provide direct comparisons which bolster the empirical support for CBT. Furthermore, Beck's extensive work on cognitive therapy for depression, also cited above, has substantially contributed to the field by elucidating the model's neurobiological correlates and therapeutic mechanisms.
Therefore, the best answer to the question about the percentage of empirically supported treatments that are cognitive behavioral would be C: 60-90%.