I was reading recently that roughly half of the psychotherapists practicing today identify themselves as being integrative. That means they do work that transcends in some way an adherence to any single approach to psychotherapy. So, what are the options in practicing an integrative approach? There are four. The primary models of psychotherapy integration are common factors, technical eclecticism, assimilative integration, and theoretical integration.According to the common factors model, theory and method are developed in harmony with core features of treatment that have been empirically shown to contribute significantly to positive outcomes; these transcend all major approaches to psychotherapy and are relevant to outcome whenever psychotherapy is conducted. In 1936 Rosenzweig posited the dodo bird hypothesis (yes, that is what it became known as), and ever since people have been arguing about whether or not this or that modality or technique is more effective than another or whether or not they are all more or less equally effective. Rosenzweig’s assertion was that all forms of psychotherapy are equally effective, and the emergence of various sets of common factors that are effective and present in all major forms of psychotherapy has become increasingly attractive as a way of explaining the positive outcomes psychotherapy can rightfully claim. Client factors, therapist characteristics, the working relationship, and specific techniques are the major common factors.Client factors include what the client as a person brings to therapy, and that entails the client’s experiences outside of therapy, the culture in which the client lives, historical events and environmental stressors, developmental or formative and traumatic experiences, general health, and levels of intelligence and adaptive capacity. The quality of the client’s participation is crucial. What clients expect from psychotherapy strongly influences the outcome. If clients believe that psychotherapy works, that they are in the presence of a competent therapist, and if they are motivated to change, the process of therapy usually takes off and becomes satisfying to all involved. Also important are the client’s experience of the therapeutic bond, the client contribution to that working relationship, the client’s openness versus defensiveness, and the client’s in-session impact of therapy events, which is what these events are like for the client and the meaning the client makes out of the process.Therapist effects come second, and these are best understood as what the therapist as a person brings to therapy rather than the techniques the therapist might utilise. Clinicians vary in such things as interpersonal skills, experience, kinds of training, values, and world views. In working with clients suffering from PTSD the following therapist effects were salient: the ability to reduce avoidance, the language used in supervision, and the therapist’s flexible interpersonal style or ability to engage in a therapeutic alliance. The reducing of avoidance was related to the level of experience of the therapist, with more experienced therapists doing better than less experienced therapists. The language used in supervision referred to how therapists referred to their clinical processes — if they were willing to discuss their struggles, if they were non-defensive, and if they were willing to follow through with suggestions provided by a supervision group. The flexible interpersonal style referred to the ability of the therapist to be both supportive and challenging, to be able to leave behind rigid protocols when interpersonal needs presented themselves and to meet people directly. The therapist is not just the delivery mechanism, but also an important part of what is delivered.The role of the therapeutic relationship in psychotherapy outcome cannot be denied. It is understood to consist of the feelings and attitudes the client and therapist have toward one another and the manner in which they are expressed. The therapeutic relationship accounts for more outcome than the treatment modality or the specific techniques used and is one of the common factors, along with client characteristics, therapist qualities, and clinical methodology.In technical eclecticism the clinician patches together his or her own pragmatic system using methods and techniques observed in the practitioners of various single-school theoretical models, relying on empirical research to formulate a practice matching interventions to clinical populations and presenting symptoms. Sometimes issues of treatment fit are mixed with common factors in such matching. Often clinicians do not simply compile a list of interventions and techniques divorced from theoretical considerations, but rather maintain a theoretical pluralism to support these various techniques. The use of technical eclecticism is compatible with a commitment to empirically supported treatments, where treatments are not necessarily whole clinical perspectives but the specific interventions and techniques associated with them, but this is a more narrow approach than evidence-based practice in psychology.In assimilative integration methods and techniques are not simply appropriated intact from other modalities; they are chewed up and digested so that when they appear in a person’s practice, they are thoroughly consistent with the main established theory that informs the clinician’s practice and are somewhat altered by their new contexts. Assimilative integration is the incorporation of perspectives and/or practices from other clinical modalities within one’s primary theoretical or therapeutic perspective, taking the novel context into account. It is first a grounding in one’s preferred approach to psychotherapy and second a willingness to systematically incorporate concepts and techniques found in other schools of thought, and specifically those that have some measure of appropriate fit to a set of symptoms. The overlap with theoretical integration is evident in the assimilative approach because there has to be at least a modest consilience between the ethos of the theoretical home base and the rationale of the technique that is assimilated into it.In theoretical integration elements of different theories are joined to form another cohesive theoretical system, one that is a true synthesis and more than a mere combination. John Norcross described theoretical integration, saying, “Theoretical integration involves a commitment to a conceptual or theoretical creation beyond a technical blend of methods. The goal is to create a conceptual framework that synthesises the best elements of two or more approaches to therapy ... Integration aspires to more than a simple combination; it seeks an emergent theory that is more than the sum of its parts and that leads to new directions for practice and research”. Theoretical integration is difficult, and the question as to what extent the integration goes is crucial. Does it extend to a common anthropology, theories of personality and psychopathology, world views, and epistemological commitments? Furthermore, theoretical integration of otherwise disparate approaches requires some kind of organising centre — an attractor that pulls the parts together and holds them there. For instance, in the practice of gestalt therapy, which is a theoretical integration from continental philosophy and German science, the central organising construct is “contacting,” which is the process in the way people meet one another and the environment.Most experienced psychotherapists practice some form of integrative work. As you can see from this description, however, it’s a complicated process that requires a psychotherapist think about what he or she is doing.