A comprehensive 2024 scoping review identifies substantial research imbalances in alexithymia (difficulty identifying and describing emotions) across neurodevelopmental populations, with autism spectrum disorder extensively studied at 49.9% prevalence but Down syndrome and dual diagnoses almost entirely absent from the literature.
Alexithymia—characterized by difficulties identifying, processing, and expressing emotions—affects roughly 10% of the general population but reaches substantially higher rates in people with neurodevelopmental disorders. This 2024 scoping review systematically examined 55 studies published between 1994 and 2024 to map current knowledge and identify research gaps across Down syndrome, autism spectrum disorder, and dual diagnosis populations.
The most striking finding is a severe research imbalance. Autism spectrum disorder dominates the literature with extensive investigation and a weighted mean prevalence of 49.9% for alexithymia in ASD populations. This substantial prevalence suggests emotional processing difficulties are common in autism. In stark contrast, Down syndrome research on alexithymia is minimal, with no established prevalence rate and only fragmentary investigation. The dual diagnosis population (individuals with both Down syndrome and autism), estimated to represent 16-18% of people with Down syndrome, remains entirely absent from the alexithymia research literature. This gap is particularly consequential given that comorbid neurodevelopmental conditions may compound emotional processing difficulties.
Six major themes emerged from the 55 studies. Beyond the prevalence disparities noted above, the review identified critical assessment limitations: current validated alexithymia tools were not designed for and lack validation in populations with intellectual disabilities. This methodological gap means clinicians lack reliable instruments to assess emotional awareness in these populations, potentially leading to underdiagnosis and missed therapeutic opportunities. On intervention approaches, the limited evidence available demonstrated moderate effectiveness (effect size d = 0.65) in ASD populations, though sample sizes were small and populations studied were heterogeneous. Neurobiological correlates pointed to dysfunction in emotion processing networks, with studies implicating atypical activity in brain regions supporting emotional awareness and regulation. However, developmental trajectory research across the lifespan remains largely absent, leaving open questions about how alexithymia manifests, changes, or compounds across childhood, adolescence, and adulthood in these populations.
The review identified seven critical research gaps with immediate implications for clinical practice and quality of life. Beyond the absence of validated assessment tools for intellectual disability and the lack of DS prevalence data, longitudinal developmental studies are missing entirely. No research examines how alexithymia unfolds across development in any neurodevelopmental population. Population-specific intervention approaches remain uninvestigated for Down syndrome and dual diagnosis populations. The authors emphasize that current evidence limitations directly constrain evidence-based practice, making it difficult for clinicians to identify who struggles with emotional awareness and how best to support them therapeutically.
If you support someone with autism, Down syndrome, or both conditions, this review highlights why emotional engagement and communication challenges may reflect underlying difficulties with emotional awareness rather than willful resistance or lack of capacity. The 49.9% alexithymia prevalence in autism suggests that roughly half of autistic individuals may struggle to identify their own emotions—a difference that fundamentally requires different therapeutic approaches than assuming emotional processing works typically.
For individuals with Down syndrome specifically, the research absence means current clinical practice lacks evidenced guidance. If you work with this population therapeutically or educationally, you're operating without established tools to assess alexithymia or validated protocols to address it. This creates an opportunity: recognizing emotional processing difficulties early and seeking out individualized assessment and support may help optimize therapeutic outcomes and quality of life, even without condition-specific research guidance.
For researchers and clinicians, the immediate priority is validation work: adapting existing alexithymia measures for intellectual disability populations or developing new assessment approaches that account for communication and cognitive differences. The next critical step is establishing baseline prevalence in Down syndrome and investigating the dual diagnosis population. Only with reliable prevalence and validated assessment tools can intervention research proceed meaningfully.
The moderate effectiveness of existing ASD interventions (effect size 0.65) suggests emotional awareness is teachable and improvable, providing some optimism. However, the small samples and heterogeneous populations studied mean these findings should be interpreted cautiously and replicated before scaling broadly.
| Attribute | Details |
|---|---|
| Study Type | Scoping review following Arksey and O'Malley framework |
| Sample | 55 studies meeting inclusion criteria (1994-2024) |
| Databases Searched | MEDLINE, PsycINFO, EMBASE, CINAHL, Cochrane |
| Key Finding | 49.9% weighted mean alexithymia prevalence in ASD; minimal DS research; zero dual diagnosis studies |
| Intervention Effectiveness | Moderate effect size (d = 0.65) in limited ASD populations |
| Primary Gap Identified | Absence of validated assessment tools for intellectual disability populations; no established DS prevalence; no dual diagnosis research |
| Journal | Frontiers in Psychology |
| PubMed ID | 42325346 |
Scoping review on alexithymia in neurodevelopmental populations (Down syndrome, autism spectrum disorder, and dual diagnosis). Frontiers in Psychology. Published 2024.
OSF registration: https://doi.org/10.17605/OSF.IO/K8UEC
ProtocolEngine provides general health information based on published research. This is not medical advice. Consult a healthcare professional before starting any supplement or health protocol.