Understanding What Shapes BPD in Adolescence
It’s common to think of adolescence as a turbulent but temporary phase—a time of mood swings, identity shifts, and high drama. For most young people, these experiences settle with age. But for some, the turbulence doesn’t fade. Instead, it deepens into something more enduring: the early signs of Borderline Personality Disorder (BPD). A major 2021 systematic review helps us understand why.
The review followed what makes symptoms persist or worsen
Researchers Gabriele Skabeikyte and Rasa Barkauskiene examined 14 longitudinal studies spanning nearly four decades, focusing on adolescents aged 10 to 18. Unlike previous research that looked mainly at the onset of BPD, this study investigated what influences whether symptoms persist or worsen during adolescence.
Their findings matter not just to clinicians but to parents, carers, and anyone supporting a young person on the edge of a full-blown diagnosis. Because what this review reveals is both sobering and empowering: some risk factors are baked in early, but many are modifiable.
Some adolescents improve over time, but others follow a more painful path where BPD symptoms stay the same or grow worse.
When symptoms stick
Across the studies, most adolescents did follow a pattern of decreasing BPD symptoms over time. But a significant group did not. In both clinical and community samples, researchers identified young people whose symptoms either remained stable or intensified through adolescence—especially girls.
This matters because it shows that BPD symptoms in adolescence are not always fleeting or harmless. For some young people, the patterns become more entrenched unless something changes. That is why early recognition matters so much.
The review identified four main domains of influence: temperament and early traits, adolescent mental health, interpersonal relationships, and family environment.
Difficult temperament is more than just a phase
Children who were emotionally intense, highly active, and less socially engaged were more likely to follow a worsening trajectory of BPD symptoms. Traits like negative affectivity—a tendency toward sadness, anger, or fear—also predicted higher BPD symptom levels.
Crucially, the link between early emotionality and later BPD was often indirect, shaped by declining self-control skills. In other words, early vulnerability did not always lead straight to later difficulty. What seemed to matter was whether the young person also struggled to build the emotional and behavioural control needed to manage that vulnerability.
This is important because it suggests that temperament is not destiny. Even if a child seems naturally more sensitive, emotionally reactive, or intense than others, their developmental path may still be changed with the right support.
The review suggests that helping young people build emotional regulation and executive functioning could make a meaningful difference over time.
A difficult temperament may raise risk, but it does not seal a young person’s fate. Skills and support still matter.
The power of co-occurring mental health problems
One of the most consistent findings across all 14 studies was the role of co-occurring mental health issues. Attention problems, hyperactivity, oppositional behaviour, substance misuse, depression, anxiety, and somatization were all linked to a slower decline or outright increase in BPD symptoms.
Importantly, these findings held true in both community and clinical samples. That means a young person does not have to already have a formal psychiatric diagnosis to be at risk. Even subthreshold symptoms can still exert powerful influence over time.
For carers, this reinforces the importance of early and integrated support. If a teenager is showing a combination of emotional instability and other mental health difficulties, it is worth taking seriously. Treating depression, anxiety, ADHD-like traits, or behavioural problems early may not just help in the present. It may also reduce the likelihood of more persistent borderline patterns becoming established.
Relationships can heal or harm
Adolescence is a time of growing social independence, and this review showed how strongly peer and romantic relationships shape BPD trajectories. Exposure to psychological, sexual, or relational violence, especially in friendships or early romances, was strongly linked to worsening symptoms.
This is a painful but important finding. Many carers focus mainly on what is happening at home, yet adolescence is also shaped by relationships outside the family. Harmful friendships, controlling romantic dynamics, humiliation, coercion, and emotional cruelty can all reinforce the very fears and instability that sit at the heart of BPD.
Surprisingly, even positive-seeming factors like intense support from a romantic partner were linked to increased symptoms in girls. This suggests that when relationships become overly enmeshed or codependent, they may reinforce fear of abandonment, dependency, or identity instability.
Notably, poor quality relationships with fathers, but not mothers, predicted slower improvement in BPD symptoms. This hints at a unique role that paternal figures may play in emotional development during adolescence.
Relationships in adolescence do not simply reflect wellbeing. They can actively shape whether BPD symptoms settle or intensify.
Family factors matter, but often indirectly
Interestingly, most parenting behaviours—such as warmth, discipline, or emotional validation—were not directly linked to changes in BPD symptoms. This may seem surprising, especially given how often parents are blamed when a young person is struggling.
The exception was exposure to domestic violence. Teens who witnessed interparental aggression had slower declines in BPD symptoms, highlighting the impact of household environment over parenting style alone.
Maternal BPD symptoms, but not parental depression, were also a predictor of higher BPD symptoms in adolescents. This points toward a more specific intergenerational pattern rather than a general effect of parental distress.
For carers, this can be both difficult and relieving to read. It means the issue is not simply whether a parent was warm enough or strict enough. The wider emotional environment matters too, especially whether home feels frightening, chaotic, or unsafe.
What this means for carers
This research paints a complex picture, but it offers a clear message: adolescence is not too late. BPD symptoms are not fixed, and their course can be influenced. As a carer, your role is not just emotional support but early detection and connection to help.
Watch for signs that go beyond ordinary teenage angst. Emotional outbursts paired with impulsivity, unstable sense of self, intense fear of rejection, self-destructive behaviour, or risky relationships may all signal something more serious. If these patterns appear alongside ADHD traits, depression, trauma, substance misuse, or chronic anxiety, the risk may be greater.
Importantly, these signs should not be dismissed as “just a phase.” Research now supports the view that adolescent BPD is real, diagnosable, and potentially modifiable.
Adolescence is not too early to notice BPD patterns, and it is not too late to change the path.
Supporting change in practical ways
If your child or the young person you care for is showing these patterns, early action matters. Seek assessment from clinicians who understand adolescent BPD rather than assuming that anyone in mental health services will recognise it properly.
Address co-occurring conditions like anxiety, ADHD, depression, trauma, or substance use early. These difficulties do not sit on the side-lines. The review suggests they are often part of what drives symptoms to persist.
Help the young person build self-control skills. This does not mean demanding more “willpower.” It means supporting routines, emotion regulation, decision-making, and structured ways of coping when feelings become intense.
Support healthy boundaries in relationships. Teenagers need closeness and belonging, but they also need protection from enmeshment, coercion, and instability. Teaching them how to recognise unhealthy dynamics may be just as important as teaching them how to cope with emotions.
Create as stable and non-violent a home environment as possible. And where needed, seek support for your own mental health too. Carers often carry enormous stress, and supporting a vulnerable adolescent is much harder when you are overwhelmed yourself.
A final word
This systematic review confirms what many carers already sense: adolescence is a window of both risk and opportunity. Some BPD symptoms will fade with time. Others will not—unless something actively changes.
Recognising the patterns, understanding the drivers, and responding early can make all the difference. Some risks begin early in life, but many of the factors linked to worsening symptoms are still open to intervention. That is where hope lies.
The message of this review is not that vulnerable adolescents are doomed. It is that trajectories can shift. Support, treatment, safer relationships, and stronger coping skills may all help prevent symptoms from becoming more severe or persistent.
What shapes BPD in adolescence is not one single cause, but a pattern of traits, mental health struggles, relationships, and environments that can still be changed.
Source note
This article is based on the 2021 systematic review by Gabriele Skabeikyte and Rasa Barkauskiene examining predictors of the course of Borderline Personality Disorder in adolescence across 14 longitudinal studies.
Read the full open-access study here: Understanding what shapes BPD in adolescence