How Alexthymia and Autism Traits Shape Personality: Understanding the Link to Personality Disorders

Autism shares social and emotional traits with certain personality disorders, like schizoid and obsessive-compulsive personality disorder.

Studying this link helps clinicians distinguish between overlapping conditions, avoid misdiagnosis, and tailor treatment more effectively, especially since autism is often diagnosed late and co-occurs with other mental health issues.

Albantakis, L., Weindel, L., Brandi, M. L., Zillekens, I. C., Henco, L., Thaler, H., ... & Schilbach, L. (2025). Alexithymic and autistic traits differentially predict personality disorder dimensions. Autism, 13623613251338650. https://doi.org/10.1177_13623613251338650

Key Points

• Focus:
  This study explored how autistic and alexithymic traits relate to specific personality disorder (PD) dimensions in clinical and non-clinical adults.
• Method:
  Researchers used a dimensional, cross-group design, applying psychometric questionnaires to 224 participants from three groups (autistic, non-autistic with social difficulties, and neurotypicals). They used regression analyses while controlling for depression, anxiety, and age.
• Findings:
  • Autistic traits predicted obsessive-compulsive personality disorder (OCPD) traits.
  • Alexithymic traits predicted borderline personality disorder (BPD) traits.
  • Both trait types predicted schizoid PD traits.
  • Neither predicted avoidant PD once depression and anxiety were accounted for.
• Implications:
  These findings clarify how social-emotional traits contribute differently to distinct PD dimensions, aiding both diagnosis and treatment by distinguishing between overlapping conditions like autism and PDs.

Rationale

What Is Alexithymia?

Alexithymia is a subclinical condition marked by difficulties in identifying, describing, and expressing emotions.

People with alexithymia often struggle to connect with their feelings or understand others’ emotions, affecting their relationships and social interactions.

What Is Autism (ASD)?

Autism spectrum disorder is a neurodevelopmental condition defined by social communication differences and restricted, repetitive behaviors. These challenges often persist from early childhood into adulthood.

Current Knowledge:

Alexithymia and autism both involve social and emotional difficulties. Around 50% of autistic individuals also meet criteria for alexithymia.

Both traits have been linked to difficulties common in personality disorders—such as emotional dysregulation, interpersonal struggles, and rigid behavioral patterns.

Research Gap:

Despite overlap, it’s unclear whether autism and alexithymia predict the same or different PD dimensions. Past studies often only looked at one of these traits in isolation.

This study simultaneously investigated both, addressing a need for a more nuanced, dimensional understanding.

Why It Matters:

Understanding these links helps clarify overlapping diagnoses in clinical practice—particularly in autism and PDs like borderline, schizoid, and OCPD.

It also supports more tailored mental health treatments that account for underlying emotional and cognitive traits.

Method

Summary:

This was a dimensional, observational study comparing trait levels and PD dimensions across three diagnostic groups using validated questionnaires and regression models.

Sample

• Total Participants: 224 adults
  • Autistic participants (AP): 89
  • Non-autistic with social difficulties (NAP): 51
  • Neurotypicals (NP): 84
• Gender: Female representation was highest in the NP group (62%).
• Age Range: Mean age ~35 for AP and NAP; ~26 for NP.
• IQ: All participants had average intelligence (IQ ≥ 85).
• Location: Max Planck Institute of Psychiatry, Germany.

Variables

• Independent Variables:
  • Autistic traits (Autism-Spectrum Quotient; AQ)
  • Alexithymic traits (Toronto Alexithymia Scale; TAS-20)
• Dependent Variables:
  • PD dimensions from the ADP-IV questionnaire:
    • Schizoid
    • Borderline
    • Avoidant
    • Obsessive-compulsive
• Covariates:
  • Age
  • Depressive symptoms (Beck Depression Inventory-II)
  • Social anxiety symptoms (Liebowitz Social Anxiety Scale)

Procedure

1. Clinical participants (AP and NAP) underwent formal autism assessments using national diagnostic guidelines and ADOS-2.
2. Neurotypical controls were selected based on absence of psychiatric diagnoses.
3. All participants completed self-report measures (AQ, TAS-20, ADP-IV, BDI-II, LSAS).
4. Data were analyzed to assess how autistic and alexithymic traits predicted PD dimensions, accounting for covariates.

Measures

• Autism-Spectrum Quotient (AQ): Measures traits associated with autism (e.g., social skills, attention to detail).
  Appropriate because it captures dimensional autistic traits in clinical and non-clinical samples.
• Toronto Alexithymia Scale (TAS-20): Assesses difficulty identifying and expressing emotions.
  Relevant due to its established role in emotion-related research.
• Beck Depression Inventory-II (BDI-II): Assesses depressive symptoms.
  Included to control for emotional distress that may affect self-reporting.
• Liebowitz Social Anxiety Scale (LSAS): Measures fear and avoidance in social settings.
  Used to control for anxiety-related confounds.
• ADP-IV: Self-report measure assessing traits across DSM-IV PD dimensions.
  Chosen for its dimensional scoring capacity and diagnostic alignment.

Statistical Measures

Researchers used multiple linear regression with bootstrapping (1,000 resamples) to:

• Control for non-normality in residuals.
• Test predictors (autistic and alexithymic traits) on each PD dimension.
• Include covariates (age, depression, anxiety) and group (AP, NAP, NP) as moderators.
• Check for multicollinearity between AQ and TAS-20, which was found to be low.

This approach allowed robust, dimensional modeling suitable for exploring trait-PD associations across varied samples.

Results

• Schizoid PD:
  • Predicted by both autistic and alexithymic traits.
  • Strongest in the NAP group compared to neurotypicals.
  • Model explained 58.9% of the variance.
• Borderline PD:
  • Predicted only by alexithymic traits.
  • No significant link to autistic traits after controls.
  • Model explained 47.6% of the variance.
• Avoidant PD:
  • Not predicted by autistic or alexithymic traits when group status was controlled.
  • Depression and social anxiety were stronger predictors.
  • Model explained 72.4% of the variance.
• OCPD:
  • Predicted by autistic traits only.
  • No effect of alexithymia.
  • Model explained 49.5% of the variance.

Insight

This study contributes a nuanced understanding of how social-emotional traits map onto personality pathology:

• Schizoid PD overlaps with both autism and alexithymia.
  Both groups show detachment and emotional flatness, but the underlying reasons may differ (e.g., lack of motivation vs. emotional blindness).
• OCPD links specifically to autism.
  Traits like rule-following, rigidity, and perfectionism resemble autistic characteristics, such as preference for routines and details.
• Borderline PD connects to alexithymia, not autism.
  Emotional instability, impulsivity, and trauma-related difficulties appear more linked to emotional unawareness than autism per se.
• Avoidant PD is complex.
  Initially predicted by both traits, but their influence vanished once depression and anxiety were accounted for—suggesting emotional distress may play a stronger role.

These findings clarify how social impairments differ across conditions. For example, someone struggling with emotion recognition (alexithymia) may present differently from someone with rigid behavior (autism), even if both face social challenges.

The dimensional approach also challenges the traditional binary of “having or not having” a diagnosis. Traits like autism or alexithymia exist on a spectrum and can influence psychological functioning in subtle but meaningful ways.

Clinical Implications

• Differential Diagnosis:
  Clinicians should be cautious when diagnosing personality disorders in autistic or alexithymic individuals, as overlapping features can obscure root causes.
• Personalized Treatment:
  • Borderline features with high alexithymia may benefit more from emotion-focused therapies.
  • Autistic traits linked to OCPD may respond to flexibility and cognitive-behavioral training.
  • Schizoid-like traits in autism or alexithymia may need distinct approaches based on the underlying mechanism (e.g., social withdrawal vs. emotional detachment).
• Screening Tools:
  Clinicians should include assessments for alexithymia and autistic traits when evaluating clients for PDs.
• Potential Challenges:
  Implementing these recommendations may require additional training, as clinicians may not routinely assess for alexithymia. There is also a risk of over-pathologizing normal variations in emotion processing or personality.

Strengths

• Large Sample Size:
  224 participants from clinical and non-clinical populations increased statistical power and generalizability.
• Dimensional Approach:
  Going beyond diagnoses, the study treated traits and disorders as spectra, aligning with current mental health models.
• Controlled for Confounds:
  Depression, anxiety, and age were statistically accounted for, ensuring results weren’t skewed by common comorbidities.
• Multi-Group Design:
  Including AP, NAP, and NP groups helped isolate the role of core traits from psychiatric diagnoses alone.

Limitations

• Correlational Design:
  The study can’t prove cause-and-effect relationships.
• Self-Report Measures:
  Tools like TAS-20 and AQ may be biased or limited in capturing traits accurately across different populations.
• Measurement Overlap:
  Autism and alexithymia can co-occur, complicating the interpretation of their individual effects.
• Sex/Gender Not Moderated:
  Analyses by sex were done post hoc but not integrated as formal moderators, missing possible gender-based patterns.

Socratic Questions

1. Why might both autistic and alexithymic traits lead to similar social difficulties but differ in their impact on personality disorders?
2. Could cultural expectations around emotional expression influence how alexithymia or autism is interpreted in clinical settings?
3. How might therapy differ for someone whose borderline traits stem from trauma versus emotional unawareness?
4. Do you think labeling social rigidity as OCPD in autistic individuals could lead to misdiagnosis? Why or why not?
5. How might the findings change the way clinicians evaluate avoidant PD in clients with anxiety or depression?
6. What could be the implications of these results for early screening and intervention in young adults?
7. Are self-report questionnaires the best way to measure traits like alexithymia? What alternatives might be more reliable?
8. In what ways does this study support or challenge the idea of personality disorders as fixed and lifelong conditions?
9. If you were designing a follow-up study, how would you address the limitations identified here?
10. How can understanding emotional processing traits improve empathy and therapeutic rapport in clinical work?