The editors have gathered a set of expert psychologists to compile multiple lines of evidence to demonstrate how existential and humanistic approaches to therapy can just be just as effective if not more so in some contexts, as other evidence-based approaches. They also highlight important multicultural considerations, as well as highlight gaps that can be filled by future research.

Chapters detail the key foundations and principles of EHT, including therapeutic presence, empathy, authenticity, therapist self-disclosure, here-and-now work, and the self within the therapeutic context. Integrative strategies including mindfulness, art therapy, experiential therapy, and equine-assisted therapy are also reviewed to demonstrate the effectiveness of specific EHT modalities that combine these foundational elements.