In clinical practice and recent literature, we’re seeing increasing discussions around how the diagnosis of Attention‑Deficit/Hyperactivity Disorder (ADHD) is applied — and whether its boundaries might be stretched to include emotional, interpersonal and personality features that historically lay elsewhere. As a psychiatrist, you’re well-aware that diagnostic clarity is crucial. This article explores:

• What ADHD core features remain well-defined

• How phenomena like Rejection Sensitive Dysphoria (RSD) fit in

• Where overlap with Borderline Personality Disorder (BPD) complicates matters

• Practical approaches for assessment, differential diagnosis and treatment

1. The Established Core of ADHD

ADHD is a neurodevelopmental disorder characterised by a persistent pattern of inattention, hyperactivity and/or impulsivity that interferes with functioning or development.
Important features include:

• Onset in childhood (prior to age 12, by DSM-5 criteria)

• Impairment across settings (school/work, home)

• Exclusion of other causes (e.g., mood, sleep, substance, intellectual disability)

What remains robust in the literature is ADHD’s link to executive function deficits (planning, organisation, working memory) and, increasingly, emotional dysregulation (though the latter is not strictly part of the diagnostic criteria, in many jurisdictions).

As one review noted, adults with ADHD often report high levels of criticism, rejection or feeling judged — particularly due to behaviours tied to inattention and impulsivity.

2. Rejection Sensitive Dysphoria (RSD): What We Know

“RSD” is a term gaining traction in both clinical discussions and patient-communities. It describes:

• Intense emotional responses (shame, anger, despair) to perceived (or real) rejection or criticism

• A tendency to interpret neutral or mildly negative events as deeply personal and identity‐threatening

Key points from the literature:

• RSD is not an official diagnosis in DSM or ICD at present.

• It is highly associated with ADHD in many sources — though numbers vary and methodological rigor is limited. For example, one article states RSD may affect “20–30 % of individuals with ADHD”.

• It overlaps in phenomenology with rejection sensitivity (a construct more broadly studied) which is linked with multiple psychiatric conditions including depression, anxiety, BPD.

• Clinical implication: When someone with ADHD presents with overwhelming emotional reactions to criticism or perceived rejection, the RSD framework can help guide understanding and intervention.

Thus: RSD may be best conceptualised as a symptom-cluster (or trans‐diagnostic vulnerability) rather than a separate disorder — at least until more formal research confirms otherwise.

3. Overlap with BPD and the Danger of Diagnostic Overlap

It’s here that things get tricky. ADHD and BPD share certain temperamental and symptomatic overlaps, including:

• Impulsivity

• Emotional lability/dysregulation

• Interpersonal difficulties

• Sensitivity to rejection or abandonment

For example, a clinical overview found that ADHD and BPD “share key clinical and temperamental similarities” and co-occur at higher than population rates.
Another resource highlights that emotional dysregulation acts as a bridge between neurodevelopmental (ADHD) and personality-pathology (BPD) domains.

Why this is clinically relevant:

• If ADHD is used as a “catch-all” for emotional/interpersonal dysregulation, we risk diluting the construct — i.e., losing specificity.

• If BPD features (e.g., chronic identity disturbance, pervasive pattern of abandonment avoidance, self-harm, unstable relationships) are attributed solely to ADHD, we might miss the appropriate treatment for personality pathology.

• The developmental trajectories differ: ADHD arises in childhood; personality disorders typically manifest in adolescence/early adulthood with patterns entrenched across domains.

Thus, there is a diagnostic tension: ensuring we recognise genuine ADHD + emotional dysregulation (and treat it), without simply re‐labelling personality-level or relational patterns under the ADHD umbrella.

4. So — Is ADHD Being “Expanded” Too Much?

Yes and no. The expansion of ADHD phenomena to include emotional reactivity and interpersonal sensitivity is understandable (given clinical reality). But the risk is:

• Blurring boundaries such that ADHD becomes “everything that’s a problem in life”

• Under-recognising other diagnoses (personality disorders, trauma-based dysregulation, mood disorders)

• Losing clarity in research (what exactly are we measuring when we say “ADHD with emotional dysregulation”?)

• Treatment drift (e.g., assuming stimulant monotherapy suffices when complex emotion/interpersonal problems exist)

From a philosophical viewpoint: The diagnostic construct must remain meaningful — too broad, and it risks becoming vacuous. As a Wikipedia entry on ADHD controversies notes: some social-constructionist views argue ADHD may be pathologising normative behaviour when thresholds are low.

In short: We must balance breadth (real-world complexity) with precision (diagnostic clarity).

5. Clinical Implications — A Pragmatic Approach

Here are some actionable takeaways you might incorporate in your practice:

Assessment

• Always begin with developmental history: ADHD must show onset in childhood (or adolescence) with impairing symptoms across settings.

• Use collateral information (family, school/work reports) especially when emotional/interpersonal features dominate.

• Assess for emotional dysregulation separately: how much is due to ADHD executive/emotion regulation deficits vs. trauma vs. personality style.

• For RSD-type presentations (intense reactions to perceived rejection): ask about frequency, triggers, functional impairment, and rule out mood/trauma/personality causes.

• Pad for differential diagnosis: BPD, Complex PTSD, mood disorders, anxiety disorders.

Treatment Planning

• If ADHD is confirmed: treat core symptoms (e.g., neuropsychological/executive deficits) with evidence-based methods (medication + behavioural/psychotherapeutic interventions).

• If emotional/interpersonal features are prominent: integrate approaches such as Dialectical Behavior Therapy (DBT), emotion-regulation therapy, interpersonal therapy.

• Address RSD symptoms (if present) by helping patients: (i) recognise and reframe interpersonal triggers, (ii) build self-compassion, (iii) develop coping skills for shame/hypersensitivity, and (iv) ensure their environment (home/work) is supportive.

• Psychoeducation is vital: Helping patients and families understand why rejection-sensitivity or emotional swings may occur can reduce shame and increase engagement. As one study noted, for adults with ADHD, criticism often erodes self-worth and triggers avoidance behaviours.

Prevention of Over-Pathologising

• Maintain a clear diagnostic rationale: e.g., “I am diagnosing ADHD because of sustained childhood onset, cross-setting impairment, executive deficits” rather than simply “you’re always emotional, so it must be ADHD.”

• Use functional impairment as a threshold — significant impact rather than just “traits”.

• Be open to dual diagnoses: ADHD may coexist with personality pathology or trauma histories — it doesn’t have to be either/or.

• Monitor for treatment drift: If you are treating “everything” as ADHD, check whether therapy should shift to more relational/interpersonal or trauma-based focus.

6. Looking Ahead: Where the Field Needs to Go

• Stronger research on constructs like RSD: prevalence, neurobiology, longitudinal outcomes.

• Refinement of emotional dysregulation in ADHD: how distinct vs overlapping it is compared with mood/personality disorders.

• Biomarkers or neuroimaging may someday help tease apart overlapping constructs — though we’re not there yet.

• Transdiagnostic frameworks: Recognising that emotional-interpersonal dysregulation cuts across ADHD, BPD, trauma, mood/anxiety disorders — perhaps focusing on processes (impulsivity, rejection sensitivity, emotional over-reactivity) rather than rigid categories.

• Clinician training: Enhancing diagnostic skill so that clinicians discern nuance rather than default to label(s) that may not fit.

Conclusion

ADHD remains a valid, meaningful diagnosis grounded in neurodevelopmental science. The phenomenon of rejection sensitivity and intense emotional reactivity (RSD) is very real in many individuals with ADHD — but it is not yet a distinct diagnostic entity. The overlap with BPD and other emotional/interpersonal disorders highlights the need for careful differential diagnosis, not diagnostic inflation.

For you as a clinician: aim for depth, resist simplification, embrace complexity — the goal is always precision helping, not just labeling. And by doing so, you help patients not only get a diagnosis, but get the right treatment.

About the Author – Dr. T. Srinivas Rajkumar

MD (AIIMS New Delhi), DNB, MBA (BITS Pilani)
Consultant Psychiatrist – Mind & Memory Clinic
Apollo Clinic (Opp. Phoenix MarketCity), Velachery, Chennai – 600042
📞 +91-8595155808 | 🌐 www.srinivasaiims.com

I specialise in ADHD assessment (clinical interviews, executive-function profiling), emotional dysregulation and integrated psychotherapy for adult neurodevelopmental and interpersonal disorders. Appointments available both offline and online.