ADHD and BPD: Is there a link?

Attention deficit hyperactivity disorder (ADHD) and borderline personality disorder (BPD) are both mental health diagnoses that can affect someone’s ability to regulate emotions, thoughts and behaviours.

They are distinct diagnoses – meaning they are not the same condition – but research and clinical experience highlight some similarities and overlaps between the two, which can make differentiating them a challenge.

This may be further complicated by the fact that some people can even be diagnosed with both ADHD and BPD – referred to as ‘comorbidity’.

So, what are the key similarities and differences between the two conditions? In this guide, clinical psychologist Dr Lisa Williams explores the unique and overlapping traits of ADHD and BPD.

Before we look at the relationship between ADHD and BPD, it’s helpful to understand more about each condition…

ADHD is a neurodevelopmental disorder that primarily affects attention and ‘executive functioning’ – the mental processes that help people plan, organise, control impulses and manage time effectively.

As a result, people with ADHD may experience differences in patience, memory and recall, as well as sustaining attention or mental effort, staying organised and following instructions. They may also fidget excessively and struggle to sit still for long periods.

There are currently three recognised subtypes of ADHD – predominantly inattentive, predominantly hyperactive/impulsive and combined.

While the key traits of ADHD are typically observed by the family in childhood, many adults continue to experience them – although the severity and how they are expressed may change over time.

ADHD can significantly impact a person’s ability to perform academically, socially and professionally.

However, people with ADHD can also experience unique ‘strengths’, including creativity and innovation, hyperfocus, enthusiasm and energy, multitasking and resilience – some of which go hand in hand with the condition, while others may be developed as a coping strategy to enhance their ability to thrive.

ADHD can be supported in various ways, according to the individual’s strengths and needs. This may include behavioural therapy – such as cognitive-behavioural therapy (CBT) – to improve focus and manage impulsivity, as well as prescribed medication to regulate attention and hyperactivity.

Everyday adjustments, such as structured routines, breaking tasks into smaller steps and using reminders or lists, can also help with organisation and time management.

If you or your child are struggling, and you think this may be because of ADHD, you may wish to seek further assessment. This should start with your GP.

ADHD assessments should be completed only by clinicians with the necessary experience and expertise in ADHD. Typically, this will be a psychiatrist, psychologist or an advanced nurse practitioner.

The Autism Service offers Child ADHD Assessments and Adult ADHD Assessments, designed to identify ADHD in individuals, so they get the support they need to thrive.

BPD is a mental health condition that affects a person’s mood and feelings, as well as how they manage their emotions and impulses.

Individuals with BPD often experience intense and fluctuating emotions, which may stem from past trauma or difficult relationships. They might struggle with fear of abandonment – leading to perceived rejection or distance – while their sense of self may also feel unstable, experiencing rapid changes in mood or identity.

Impulsive behaviours – such as risky actions or difficulty managing strong emotions – can be common coping mechanisms used to deal with the overwhelming need for connection, stability and safety.

BPD is often characterised by differences in emotional stability, fear of abandonment and distorted self-image.

As a result, many people with BPD may present or experience impulsive behaviours, unstable relationships, chronic feelings of emptiness, dissociative symptoms and even suicidal behaviour or self-injury.

Families and loved ones may spot these signs of BPD in the form of mood swings, risky behaviours such as substance abuse or spending sprees, unstable relationships and dramatic shifts in goals, values and interests. It can be difficult for these individuals to maintain stable relationships and jobs or manage emotions.

Like those with ADHD, though, individuals with BPD also often possess unique strengths – including emotional sensitivity, strong intuition, passion and dedication, resilience, creativity and an ability to experience emotions with great intensity that can lead to a rich inner world.

Appropriate therapy and treatment – such as dialectical behaviour therapy (DBT) – can help many people with BPD explore the pain at the core of their distress and develop ways to regulate their emotions in a healthy way.

In turn, this can help these individuals to improve their relationships and reduce impulsivity.

Though ADHD and BPD are distinct diagnoses, they share several overlapping characteristics that may confuse clinicians and individuals alike.

Some of the most notable similarities include:

• Impulsivity: In ADHD, impulsivity may appear as a tendency to act on spontaneous thoughts or feelings, such as speaking out of turn or engaging in adventurous behaviours, driven by a desire for immediate engagement or excitement. In BPD, impulsivity tends to manifest more emotionally, often driven by intense feelings of anger, frustration or fear of abandonment.
• Specific needs with emotions: People with ADHD may experience intense emotional responses or frustration that can arise when feeling overwhelmed by tasks or when there is a sense of not being fully understood. In BPD, emotional responses are more pervasive, with individuals often feeling emotions at an extreme intensity and having difficulty returning to a baseline state.
• Differences with relationships: People with ADHD may experience differences in maintaining focus or staying organised in social situations, which can sometimes result in differences in communication. Those with BPD may have intense fluctuations in relationships marked by a fear of abandonment and rapid emotional shifts, often engaging in behaviours that can unintentionally undermine relationships.
• Differences with self-control: People with ADHD may find it challenging to regulate impulses related to attention or activity levels, often requiring strategies to help manage focus and energy in different situations. Those with BPD may have difficulty controlling their emotions, actions and reactions during times of stress.

While there are some similarities in how ADHD and BPD present in individuals, there are also some distinct differences between the two conditions, including:

• Core features: ADHD is primarily a condition with differences in attention, hyperactivity and impulsivity, stemming from neurodevelopmental changes. BPD, on the other hand, is a personality disorder characterised by instability in mood, relationships, self-image and behaviour, often rooted in early trauma or attachment difficulties.

• Emotional experience: While both conditions involve difficulty managing intense emotions, the emotional experience in BPD tends to be more extreme and widespread. People with BPD can experience rapid and intense mood swings, often in response to things around them, such as perceived rejection or abandonment. In contrast, strong emotional expression in ADHD is typically related to frustration with attention or task demands, and is less likely to be linked to interpersonal fears.

• Long-term patterns: ADHD differences are typically more stable over time and may be less influenced by interpersonal relationships. The emotional instability and impulsivity seen in BPD, however, tend to be more directly tied to the individual’s relational world and internal sense of self, often changing based on mood and circumstances.

• Underlying causes: ADHD is often rooted in neurobiological factors, such as genetic predispositions and brain structure differences. BPD, by contrast, is often linked to environmental factors – particularly early childhood trauma, abuse or neglect, and is shaped by the individual’s interpersonal experiences.

The many similarities and overlapping traits of ADHD and BPD can make it difficult for individuals and loved ones to tell between the two conditions. This is why it’s important to access professional help to get an accurate diagnosis that can support the individual to manage their condition and start to thrive.

However, there are some considerations that may help differentiate between ADHD and BPD in some people.

Firstly, consider the timing of experiences. ADHD differences typically emerge in childhood – often before the age of 12. They are persistent and can be traced back to early developmental stages. In contrast, BPD experiences usually emerge in adolescence or early adulthood and are more related to emotional regulation and interpersonal relationships.

So, if a person has a longstanding history of attention or hyperactivity differences dating back to childhood, ADHD is likely a more accurate diagnosis.

It’s also important to consider the individual’s emotional regulation. In ADHD, challenges in managing intense emotions often occur in response to frustration or encounters related to tasks and attention, whereas in BPD, emotional responses are usually tied to interpersonal dynamics, such as perceived abandonment or rejection.

The intensity and variability of emotions in BPD tend to be more dramatic and triggered by relational experiences, unlike the frustration-based emotional challenges common with ADHD.

Another key differentiator is the quality and instability of relationships. People with BPD tend to experience extreme fluctuations in how they view and interact with others, often swinging between idealisation and devaluation. This instability in relationships is often linked to fears of abandonment and feelings of emptiness.

People with ADHD may also have difficulty maintaining relationships, but this is often due to differences in remembering, attentiveness or spontaneous actions, rather than emotional dependency or abandonment fears.

Both conditions often present in spontaneous actions – but the context and nature of this can differ.

In ADHD, spontaneous actions are often more external, such as being eager to share thoughts or quick decision-making without considering consequences. In BPD, impulsivity tends to be more emotionally driven, often manifesting as self-destructive behaviours such as self-harm, substance abuse or reckless spending, in response to emotional pain.

Finally, it’s important to consider the role of trauma in the individual’s experiences. While ADHD is a neurodevelopmental disorder, BPD is often linked to early childhood trauma, neglect or abuse.

A comprehensive assessment that includes a trauma history can be crucial in differentiating these two disorders. BPD is more likely to be associated with a significant history of emotional trauma, while ADHD is not.

The Autism Service offers Child ADHD Assessments and Adult ADHD Assessments, designed to identify ADHD in individuals, so they get the support they need to thrive.

Our diagnostic assessments are of the standard completed by the NHS that looks at whether ADHD explains your presentation.

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