Personality disorders (PD) are among the most common psychiatric disorders, the most studied being borderline personality disorder (BPD), a disorder that affects approximately 1.6% of the general population and is characterised by significant difficulties in emotion regulation, identity and interpersonal relationships. Currently, categories of PD are criticised and many authors have highlighted the need for a more dimensional assessment of PD, using the association of a general factor (described as the level of personality functioning, assessed on personal and interpersonal functioning) with several personality traits used to describe specific personality characteristics (negative affectivity, antagonism/dissociality, detachment, disinhibition, anankastia, psychoticism). The two main models are the DSM-5 alternative personality disorder model (AMPD) and the International Classification of Diseases 11th edition personality disorder model (ICD-11). In particular, several works have suggested that the BPD criteria are one of the most important markers of general personality functioning. While these new models offer new and very exciting possibilities in terms of diagnostic assessment, they have struggled to spread across clinical services ; and, to date, no evidence-based treatments have been developed from these models, limiting their usefulness. Furthermore, these models are also limited by the nature of personality traits (Criteria B), as these represent rigid and stable patterns of dysfunction that may be difficult to represent the complex day-to-day fluctuations in internal psychic coherence and interpersonal functioning characteristic of PD.
One of the most recent treatments for BPD is Good Psychiatric Management. This has proved as effective as specialist therapies such as dialectical behaviour therapy and has also been developed for other personality disorders (notably narcissistic and obsessional-compulsive PD). Each adaptation is based on a specific conceptualisation designed to represent the main ways in which an individual may dysfunction in the personal and interpersonal domains. According to these conceptualisations, each of these three personality disorders presents a specific trigger for its difficulties: threat to relational dependence with fear of rejection and abandonment for borderline PD, threat to self-esteem for narcissistic PD, threat to ability to control for obsessive PD. Thus, some authors have suggested that the development of an adaptation of the GPM incorporating both the central aspects of the dimensional models, but also each of these different triggers in a non-exclusive manner (as they may be found to a greater or lesser extent in each patient suffering from PD), could be both feasible and useful, in particular to resolve the above-mentioned problems.
Indeed, like traditional dimensional models, GPM offers the possibility of a dimensional approach, with personality functioning assessed by the presence or absence of the BPD criteria, and features of personal and interpersonal dysfunction considered holistically using GPM's trigger-based approach. However, unlike traditional dimensional models, GPM has been empirically tested and found to be effective in treating patients who meet the criteria for BPD. In addition, it offers an approach to personality characteristics that is simpler, easier to understand, more accessible to psychoeducation and closer to patients' everyday experience than the personality traits classically used in dimensional models. In addition, although each adaptation of the GPM focuses on different PDs, much of the content remains the same: making and announcing the diagnosis, psychoeducation, case management, recurrent assessment of progress and reassessment if there is no response, multimodal approach including psychodynamic and behavioural psychotherapy, anticipation of crises, and management of symptomatic medication, etc. This may be linked to the fact that, although each disorder has specific triggers/traits, the underlying level of personality functioning is represented by BPD criteria and is therefore expected to be treated by the same psychotherapeutic content. Thus, a dimensional adaptation of GPM seems both relevant and feasible to address the problems of conventional dimensional models, namely the lack of existence of evidence-based treatments associated with these models, and the aspecific nature of personality trait-based approaches.
Altogether, we developed a dimensional adaptation of the GPM (GPM-extended), aiming to treat patients fulfilling the criteria for BPD dimensionally by incorporating elements from the adaptations for narcissistic and obsessional personality disorders. In terms of content, GPM-extended takes the common part of the treatment from the three adaptations and uses it as a basis, while also offering the possibility of constructing treatment goals and exposure targets that are much more specific to a given patient, in particular by carrying out an initial assessment and prioritisation of the various triggers. If this adaptation were to be shown to be effective, it would ultimately improve the diagnostic assessment and management of patients fulfilling BPD criteria, by offering treatment that is more tailored to each profile.
