ABSTRACT
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.
