Repetitive Behaviors In Autism And OCD: A Systematic Review

Autism and obsessive-compulsive disorder (OCD) share notable similarities in repetitive behaviors, presenting challenges for differential diagnosis and treatment planning. Both conditions can involve various types of repetitive behaviors, including:

1. Ritualized routines: Following strict patterns or sequences in daily activities.
2. Repetitive movements: Such as hand-flapping in autism or compulsive touching in OCD.
3. Intense interests: Preoccupation with specific topics or objects, though the nature and function may differ between conditions.
4. Ordering and arranging: Needing items to be in a particular order or symmetry.
5. Repetitive thoughts: Persistent, intrusive thoughts in OCD or fixations on specific topics in autism.
6. Verbal repetition: Echolalia in autism or repetitive phrases in OCD.

These behaviors can vary in intensity and presentation between individuals and across the lifespan. Additionally, autism and OCD often co-occur, with over 17% of autistic individuals also meeting criteria for OCD, further complicating the clinical picture.

O'Loghlen, J., McKenzie, M., Lang, C., & Paynter, J. (2024). Repetitive behaviors in autism and obsessive-compulsive disorder: A systematic review. Journal of Autism and Developmental Disorders. Advance online publication. https://doi.org/10.1007/s10803-024-06357-8

Key Points

1. The study found considerable overlap in the expression and content of repetitive behaviors between autistic individuals and those with OCD, making differential diagnosis challenging.
2. No significant differences were generally found in overall intensity of autism-related restricted and repetitive behaviors and interests (RRBIs) between autistic individuals, those with OCD, and those with both conditions.
3. Individuals with OCD typically showed greater overall obsessive-compulsive symptom severity compared to autistic individuals without OCD.
4. Mixed findings were reported regarding the content of repetitive behaviors, with some studies finding differences in specific types of behaviors (e.g., hoarding, checking) between groups.
5. Factors associated with repetitive behaviors included neurological differences, executive functioning, social/communication factors, and age, though findings were often mixed or limited.
6. The research was limited by a lack of diversity in sampling, with underrepresentation of certain groups (e.g., non-White individuals, those with intellectual impairments).
7. The study highlights the importance of understanding the function and experience of repetitive behaviors, rather than just their outward expression, for accurate differential diagnosis and treatment planning.

Rationale

This systematic review aimed to examine similarities and differences in repetitive behaviors between autistic individuals and those with obsessive-compulsive disorder (OCD).

The rationale for this study stems from the diagnostic overlap and high co-occurrence rates between autism and OCD, as well as the phenotypic similarities in repetitive behaviors observed in both conditions (van Steensel et al., 2011).

Previous research has highlighted challenges in differentiating between repetitive behaviors attributable to autism versus those related to OCD, which can impact accurate diagnosis and appropriate treatment planning (Paula-Pérez, 2013; Jiujias et al., 2017).

While previous narrative reviews have begun to explore this topic (Paula-Pérez, 2013; Jiujias et al., 2017), a systematic approach was needed to provide a comprehensive and up-to-date synthesis of the quantitative literature.

This study aimed to address this gap by systematically examining similarities and differences in repetitive behaviors across these populations in terms of expression, content, and associated factors.

Method

The study followed the Preferred Reporting for Items for Systematic Reviews and Meta-Analyses (PRISMA) statement guidelines.

A systematic search was conducted across five electronic databases: Science Direct, PsycINFO, Web of Science, Scopus, and CINAHL.

Search strategy and terms

Search terms were grouped by target population (autism and OCD) and behavior of interest (RRBIs and compulsive behaviors).

The initial search was conducted on August 18, 2022, with an updated search on June 30, 2023.

Inclusion and exclusion criteria

Inclusion criteria were:

1. Participants of any age with autism and/or OCD diagnosis
2. Quantitative study design
3. Included a measure of RRBIs and/or compulsive behaviors
4. Comparison between diagnostic groups
5. Peer-reviewed and full-text articles
6. Written in English

Exclusion criteria included non-human research, participants without formal diagnoses, single clinical population studies, and qualitative studies.

Statistical measures

The review employed both quantitative and narrative synthesis of the data. Categories of behavior were determined based on the measures used to assess repetitive behaviors across studies.

Results

Expression of Repetitive Behaviors:

• Most studies (91%) found no significant differences in overall intensity of RRBIs between autistic individuals, those with OCD, and those with both conditions.
• The majority of studies (86%) reported individuals with OCD had significantly greater total obsessive-compulsive symptom severity compared to autistic individuals without OCD.
• Studies comparing individuals with OCD to those with both conditions generally found no significant differences in total obsessive-compulsive symptom severity (67% of studies).

Content of Repetitive Behaviors:

• Mixed findings were reported for the content of autism-related RRBIs, with limited studies examining this aspect.
• More consistent patterns emerged for OCD-related compulsions, though exceptions were noted:
  • Counting and repeating compulsions were generally similar across groups.
  • Checking compulsions were more frequently reported in individuals with OCD.
  • Hoarding compulsions were more frequently endorsed by autistic adults compared to adults with OCD.
  • Mixed findings were reported for washing/cleaning and ordering/arranging compulsions.

Factors Associated with Repetitive Behaviors:

• Neurological factors: Some studies associated the intensity of repetitive behaviors with differences in glutamate concentration or striatal activity, though findings were limited.
• Executive functioning: Challenges in executive functioning were associated with greater intensity of repetitive behaviors in autistic children, but not consistently in children with OCD.
• Social and communication factors: Some studies found associations between social difficulties and obsessive-compulsive symptom severity, though findings were limited.
• Psychological/experiential factors: Limited studies reported on these factors, generally finding no differences in metacognitive beliefs or control associated with repetitive behaviors between groups.
• Age: One study found sameness behavior to be more prevalent in younger children with OCD, but not in autistic children.

Insight

This systematic review provides a comprehensive analysis of the current literature on repetitive behaviors in autism and OCD, highlighting the considerable overlap in behavioral presentations between these conditions.

The findings suggest that while some distinctions can be made at a group level, particularly in terms of overall obsessive-compulsive symptom severity, differentiating between autism and OCD based solely on the expression or content of repetitive behaviors remains challenging.

The study extends previous research by systematically examining a wide range of factors associated with repetitive behaviors, including neurological, executive functioning, and social/communication factors.

However, the mixed and often limited findings in these areas underscore the need for further research to better understand the underlying mechanisms driving repetitive behaviors in each condition.

A key insight from this review is the importance of considering the function and experience of repetitive behaviors, rather than just their outward expression, for accurate differential diagnosis and treatment planning.

This aligns with previous suggestions by Paula-Pérez (2013) regarding the potential importance of emotional valence in differentiating between autism and OCD-related repetitive behaviors.

Future research directions could include:

1. More in-depth examinations of the content of autism-related RRBIs between groups.
2. Studies focusing on the underlying motivations and functions of repetitive behaviors in each condition.
3. Longitudinal studies tracking changes in repetitive behaviors over time and their associations with various factors.
4. Research including more diverse samples, particularly individuals with intellectual impairments and from diverse ethnic backgrounds.

Strengths

The study had several methodological strengths:

1. Adherence to PRISMA guidelines for systematic reviews.
2. Comprehensive search strategy across multiple databases.
3. Inclusion of a wide range of studies examining various aspects of repetitive behaviors.
4. Rigorous quality assessment of included studies.
5. Consideration of both autism and OCD-specific measures of repetitive behaviors.
6. Examination of associated factors beyond just behavioral presentations.

Limitations

This study also had several methodological limitations, including:

1. Limited diversity in sampling, with underrepresentation of non-White individuals and those with intellectual impairments.
2. Exclusion of grey literature and non-English publications, potentially introducing bias.
3. Lack of input from individuals with lived experience of autism or OCD in the included studies.
4. Heterogeneity in measures used across studies, making direct comparisons challenging.
5. Limited examination of sex and gender differences in repetitive behaviors.

These limitations impact the generalizability of the findings and highlight the need for more diverse and inclusive research in this area.

Implications

The findings of this review have significant implications for clinical practice and research:

1. Differential diagnosis: The considerable overlap in repetitive behaviors between autism and OCD suggests that clinicians should not rely solely on the presence or intensity of these behaviors for diagnosis. A more comprehensive assessment considering the function, motivation, and subjective experience of repetitive behaviors is necessary.
2. Treatment planning: Understanding the similarities and differences in repetitive behaviors across these conditions can inform more tailored interventions. For instance, treatments targeting executive functioning may be more relevant for autism-related repetitive behaviors.
3. Comorbidity considerations: The high rates of co-occurrence between autism and OCD highlight the importance of screening for both conditions in clinical settings, even when one diagnosis is already established.
4. Research directions: The review underscores the need for more nuanced research examining specific subtypes of repetitive behaviors and their underlying mechanisms in both autism and OCD.
5. Inclusive practices: The limitations in sampling diversity emphasize the importance of more inclusive research practices to ensure findings are generalizable across different populations.

References

Primary reference

O’Loghlen, J., McKenzie, M., Lang, C., & Paynter, J. (2024). Repetitive behaviors in autism and obsessive-compulsive disorder: A systematic review. Journal of Autism and Developmental Disorders. Advance online publication. https://doi.org/10.1007/s10803-024-06357-8

Other references

Jiujias, M., Kelley, E., & Hall, L. (2017). Restricted, repetitive behaviors in autism spectrum disorder and obsessive–compulsive disorder: A comparative review. Child Psychiatry and Human Development, 48(6), 944–959. https://doi.org/10.1007/s10578-017-0717-0

Paula-Pérez, I. (2013). Differential diagnosis between obsessive compulsive disorder and restrictive and repetitive behavioural patterns, activities and interests in autism spectrum disorders. Revista De Psiquiatría Y Salud Mental (English Edition), 6(4), 178–186. https://doi.org/10.1016/j.rpsmen.2012.07.006

van Steensel, F. J. A., Bögels, S. M., & Perrin, S. (2011). Anxiety disorders in children and adolescents with autistic spectrum disorders: A meta-analysis. Clinical Child and Family Psychology Review, 14(3), 302–317. https://doi.org/10.1007/s10567-011-0097-0

Keep Learning

1. How might the ego-syntonic vs. ego-dystonic nature of repetitive behaviors in autism and OCD, respectively, influence treatment approaches?
2. What ethical considerations should be taken into account when conducting research on repetitive behaviors in autistic individuals or those with OCD?
3. How might cultural factors influence the expression and interpretation of repetitive behaviors in different populations?
4. Given the overlap in repetitive behaviors between autism and OCD, how might this impact our understanding of these conditions as distinct diagnostic categories?
5. What role might sensory processing differences play in the manifestation of repetitive behaviors in autism versus OCD?