Reviewing hundreds of studies on psychotherapy outcome, the factor that most often is associated with successful therapy is always the same—the quality of the client–therapist relationship. Therapists do most to make the client feel secure.

The therapeutic relationship is more important than the theoretical orientation or particular methods used. The therapeutic relationship—be it a therapist and client, or a healing parent and wounded child—is the most powerful curative factor. Since interpersonal trauma is created by hurtful relationships, the “cure” requires a relationship that has the same ingredients as a healthy (“secure”) parent–child relationship: trust, safety, empathy, emotional attunement, limbic resonance, support, and helpfulness.

It is generally accepted that therapists function as a secure base for their clients. Therapists possess the same characteristics as secure attachment figures. For children, attachment figures provide a secure base so that they can explore, learn, and develop in healthy ways. Similarly, therapists serve as a reliable and trustworthy figure—a secure base. Clients use the safety of the therapeutic relationship to acknowledge and discuss feelings and experiences that were denied and avoided, and to try out new behaviors, mindsets, and relational patterns. The therapist’s support and acceptance helps reduce anxiety and distress, so clients can learn about prior and current relationships and begin the process of change.

There are many therapist characteristics that engender a secure base. Therapists are emotionally available, sensitive, and responsive in predictable and consistent ways. They are attuned to client’s needs and emotions, both verbally and nonverbally. Therapists provide empathy, understanding, support, encouragement, and positive mentoring. They mitigate anxiety, stress, and emotional pain, and facilitate new solutions and experiences. The therapist and client establish a positive working alliance, a psychologically protective holding environment.

Research supports the idea that therapists function as a secure base. Studies show that therapists are perceived as providing the same secure base as spouse and family, are considered a safe haven to turn to for comfort during distress, provoke separation protest when absent, and produce feelings of safety, acceptance, and support in clients.