Disorder of personality in adolescence is a complex concept. On the one hand, it may be hard to distinguish personality pathology from normal developmental impermanence and instability. A developmental perspective demands that we keep an open mind about pathology trajectories, and balance resilience against vulnerability factors (Werner 1993). On the other hand, a small subgroup of young people do seem to present with emerging psychopathology that resembles adult personality disorder, where early diagnosis is likely to lead to early interventions and thus improve prognosis. The challenge lies in getting the formulation right. An inaccurate diagnosis of personality disorder in a young person may focus attention away from interventions that improve the caregiving environment at home, or stigmatise a young person in ways which ultimately do more to increase their problems. In this chapter, we will explore these issues in some detail, basing our views on our work in a residential secure unit for young people.

Difficulties in diagnosing personality disorder in adolescents

A key debate about the diagnosis of personality disorder in adolescents is between those who argue that personality is not fully formed until early adulthood, and those who argue that some personality traits are present and stable from early childhood.

Continuity and traits

Theories of personality development and continuity from childhood to adulthood are summarised by Caspi et al (2005). Certain clusters of adult traits, such as neuroticism, extraversion, conscientiousness, agreeableness and openness (the so-called ‘Big Five’ personality traits; Ehrler et al, 1999), have been identified in pre-school children. Their presence in childhood predicts later behaviours (Shiner, 2005), suggesting continuity of certain traits. Other studies have described the longitudinal relationship between childhood personality traits and behaviour and adult personality traits (John et al, 1994; Caspi et al, 2003, 2005; Shiner & Caspi, 2003).