Categories allow us to create order, altering the way we are able to act and interact, but they are also by nature constraining, creating divisions that must be agreed to track reality in order to be useful. Work in early intervention psychiatry has expanded over the past 30 years, and from the initial strong focus on psychosis, epidemiological research has shown that high risk for psychosis is a pluripotential state that can lead to a range of disorders, or none, and that psychosis can also develop from non-psychotic syndromes. This diagnostic instability, with heterotypic and homotypic progression of psychopathology, has supported a view of multidimensional, evolving illness, particularly for those with onset during the intense neurobiological and sociodevelopmental change of adolescence and young adulthood. Early intervention then appears both as requiring broad, diagnostically agnostic care for early-stage mental health conditions, and as needing to focus on a range of disorders beyond psychosis.
Personality disorders are an area where categories are often discussed and where early intervention is key. Through much research in the past two decades, there is now a strong argument for a dimensional approach to personality disorders, viewing them in terms of severity rather than as separate categories. This view conceptualises personality disorders primarily in terms of the organisation of self (ie, identity and self-directedness) and interpersonal functioning (ie, empathy and intimacy), and some argue that the key factor is a disturbance in the coherence of the self. This coherence emerges first during adolescence as an ability to create a narrated, abstract, integrated sense of self, even though personality traits are present before then. The nosology, development, and nature of personality disorders continue to be discussed, but the goal must also always be furthering appropriate care.
Much of the work in personality disorders in young people has focused on borderline personality disorder. In parallel with shifting classification, research has shown borderline personality disorder diagnoses to be reliable and valid in young people (aged 12–25 years) across the lifespan. However, in some places, clinicians are reluctant to make a diagnosis. But diagnoses can also be viewed as doorways rather than boxes—as a way to mediate support for individuals. Young people with borderline personality disorder features have high levels of distress, and those features are associated with low occupational and educational attainment, lack of close relationships and increased partner conflict, low levels of social support and life satisfaction, high levels of internalising, externalising, and psychotic symptoms, and high levels of self-harm and suicide attempts.
Hesitance to make the borderline diagnosis is related to debates around the term and to stigma and negative associations, as a bad label that sticks for life. But such stigma can be challenged by foregrounding disturbance to the self rather than seeing difficult behaviour, and research has shown that change is possible with access to good care. Withholding a diagnosis prevents that access, and in some patient communities, diagnosis is accepted positively as identification of a disorder rather than a negative aspect of the person. Some debates focus on borderline personality disorder being a form of post-traumatic stress disorder, but trauma is a non-specific risk factor for various psychiatric disorders, and this classification overlooks the 29% of people with borderline personality disorder who have not experienced childhood adversity. Other debates focus on emotional dysregulation, although it can also be argued that the behavioural symptom of emotional dysregulation is driven by the core lack of narrative self coherence. Beyond such debates, the danger of prioritising any one aspect is the lure of no longer listening to each person’s full story.
Dialectical behavioural therapy and mentalisation-based therapy have the most substantive evidence for borderline personality disorder, but research has also suggested that long-term psychotherapy is not the only option. The MOBY trial indicated that effective early intervention was not reliant on availability of specialist psychotherapy but did require youth-oriented clinical case management and psychiatric care. The worlds of early intervention psychiatry and personality disorder research need to work together. Classification is crucial for understanding personality pathology, and there is a need for developing better access to early intervention, family engagement, and psychoeducation, with structured crisis planning, psychotherapeutic, and more scalable care. More work in this area can change and save lives.