A behavioural approach to diagnosis
Linehan initially developed DBT for individuals who met the criteria for BPD as specified in DSM-IV the diagnostic classification system in use at the time (American Psychiatric Association, 2000). Since its inception DBT has conceptualized the diagnostic criteria behaviourally, i.e. characteristics outlined in diagnostic criteria are simply descriptions of behaviour. DBT’s behavioural conceptualization of diagnosis flows from its radical behaviourist stance that any response the organism makes (e.g. overt motor behaviour, thoughts, emotions and sensations) constitutes behaviour. Some of the diagnostic criteria for BPD, both in DSM-IV and in its revision, DSM-5 (American Psychiatric Association, 2013) refer to overt behaviours, for example, suicidal behaviours and impulsivity. Other criteria refer to covert behaviours of the client, such as identity disturbance.
Distinctively, DBT argues that the successful reduction or removal of the behaviours that constitute the diagnosis removes the diagnosis itself. A behavioural approach argues that: “A self or personality is at best a repertoire of behaviour imparted by an organized set of contingencies” (Skinner, 1974, p. 167). Thus, from a behavioural perspective, personality, and hence personality disorder, is only a series of overt and covert behaviours. All of these behaviours, overt and covert, are amenable to change using cognitive and behavioural principles and procedures (see Chapters 18-23). Once the behaviours change and the client neither displays the overt behaviours, nor experiences the covert behaviours (other than to a degree and intensity similar to the rest of the community) then the personality disorder is gone. Thus, DBT therapists in their work with clients develop behaviourally specific targets (Chapter 16) to address with CBT principles and procedures. This behavioural perspective contrasts with other theoretical models in which the idea of a personality disorder hinges conceptually on an “underlying personality organization” that causes the behavioural manifestations listed in the diagnostic criteria. In such models, curing the client requires changing the underlying personality organization.
Given the behavioural thrust of the treatment, the rationale for continuing to use a medical diagnostic system warrants explanation. As a treatment, DBT emphasizes effectiveness and as such strongly values empirical data. Currently, empirical investigation into the origins and maintenance of psychiatric disorders and the effectiveness of psychotherapy utilizes the diagnostic system. By using this system to anchor the phenomena DBT aims to treat, the treatment can access empirical literature in related fields and apply these findings directly to its understanding of the disorder and, more importantly, modify the treatment in the light of new developments.
Using the extant diagnostic system has a further benefit, namely, many clients find validation and comfort from a diagnosis to describe their difficulties. There are, however, negative aspects to diagnosing clients. First, as many clients, and often clinicians too, believe that a personality disorder diagnosis describes an unchanging malfunction in an individual’s personality, they naturally experience hopelessness in the face of the diagnosis. Indeed, given data from early studies on both the prognosis for clients with a borderline diagnosis and treatment outcome, a degree of pessimism was understandable. This early pessimism has recently changed with the advent of effective treatments for BPD, of which DBT is one (see Chapter 30), and more recent studies of prognosis (Zanarini et al., 2003). Second, clients and clinicians alike are concerned about the stigma attached to the diagnosis. While the outcome data on the efficacy of the treatment address some of the hopelessness of clients and clinicians, the behavioural conceptualization assists with both of these problems. By describing diagnosis as no more than behavioural patterns that the treatment targets and that are amenable to change, clients and clinicians can both remain hopeful, as well as focused on behaviours to change. For the client keen to avoid the stigma of a diagnosis, DBT offers a route to change those behaviours that frequently lead to stigmatization.
DBT strongly emphasizes enhancing clients’ capabilities in a range of areas, including an understanding of both the diagnosis of BPD and the treatment’s conceptualization of the diagnosis. Consequently, during assessment and pre-treatment, DBT therapists discuss the diagnostic criteria with the client, identifying which of the criteria the client meets. This discussion provides an opportunity for the therapist to assess the client’s reactions to the diagnosis, to treat any problematic responses and to orient the client to the approach DBT takes to the treatment of the behaviours identified by the diagnosis.
This page intentionally left blank