Mark Williams and Danny Penman open by presenting Mindfulness-Based Cognitive Therapy (MBCT) — an evidence-based clinical approach combining mindfulness meditation with cognitive therapy principles — as effective for managing difficult thoughts and emotions, particularly recurring depression and anxiety patterns.

Why this evidence-based clinical grounding matters:

• MBCT has substantial clinical research support, particularly for preventing depression relapse, distinguishing this approach from less rigorously evidence-based mindfulness applications
• Williams's direct involvement in MBCT's original clinical development provides credible expert grounding for the book's subsequent detailed practical guidance
• This opening establishes the book's foundational evidence-based premise, motivating its subsequent detailed structured practical program

This opening establishes the book's foundational evidence-based premise, presenting MBCT as a clinically validated approach for managing difficult thoughts and emotions, particularly depression relapse prevention.