Self-injurious behaviour (SIB) has been described as self-inflicted physical harm. This includes biting, scratching, head banging and skin picking. SIB is common in the population of individuals with learning disabilities and in particular those with Autistic Spectrum Disorder (ASD). These types of behaviour can have devastating consequences on the individual family and carers. These include social exclusion, reduced quality of life, serious injury, and even in some cases, loss of life.

Previous studies have paid less attention to the correlation between age and severity of SIB in the ASD population. The adolescent period may be related to increased incidence and severity of SIB due to a multitude of factors- increased social expectation, hormonal fluctuations, changes to care provision and co-morbidity with other issues, including anxiety and depression.

The authors of this paper, Rattaz, Michelon, and Baghdadi, suggest that it is important to examine adolescence and the risk factors associated to SIB in individuals with ASD, during this time.

Method

Sample

152 participants took part in this study- recruited from 46 specialist centres between the ages of 3 and 7 years old. Participants were followed up as part of another longitudinal study (epiTED).

A cross-section subset looking only at SIB was collected for the purpose of this paper.

All participants had a diagnosis of ASD in line with the WHO diagnostic research criteria, and were interviewed for the purpose of this study using the Autism Diagnosis Interview-Revised (Lord, et al. 1994).

Measures

SIB information was collected during adolescence using the Aberrant Behavior Checklist (ABC). The authors defined three groups from scores collected- high SIB, low SIB, and without SIB.

Environmental and clinical data was also collected in line with the following variables:

• Social demographic information and parental quality of life
• Associated medical conditions
• ASD severity using CARS (Scholper, et al. 1998)
• Expressive speech evaluated by clinicians from observational data
• Adaptive behaviours were measured using the VABS (Sparrow et al. 1984)
• Psychological development was tested in two domains: Object-related cognitive functions and Person-related cognitive functioning

Results

In total 38.5% participants showed a presence of challenging behaviour and this was further divided according to the severity subsets (16.6%= Low SIB and 19.2%= High SIB).

Analysis of the subsets of SIB severity, and the environment and clinical factors, showed significant differences between the SIB groups.

• Examination of median scores showed that those with low and high SIB showed more aberrant behaviors in comparison to those without SIB
• Those with low and high SIB had significantly different CARS score, lower adaptive skills, object and person cognition (p<0.001)
• Only 21% of those in the high SIB and 32% of those in low SIB group where able to use functional language (in comparison to 60% without SIB) (p< 0.001)
• Results also found no significance between SIB and parental social-economic status. Although parents of adolescents with high SIB reported a lower quality of life
• The severity of autism symptoms appeared to be the highest risk factors for SIB in adolescence (p = 0.04)

Limitations of study

• The sample was taken from a pre-existing longitudinal cohort of participants, potentially leading to observational bias in those chosen
• Measures used at this stage in the study were not the same as those used at previous time points of data collection in the original longitudinal research- therefore, the authors cannot compare the findings in this paper to the previous or future findings of the original EpiTED study
• The study reported only 38% of participants with ASD showed SIB- which in comparison to other literature, tends to be in the lower proportion (other studies finding up to 50% incidence of SIB) suggesting that the sample used here may not be fully representative of this population

Discussion

Despite limitations of this study, the results found here clearly point to the need for more research in this area. Severity of ASD symptoms do seem to be related to the incidence of SIB during adolescence.

However, the findings also showed that this predisposition is observed as being present at all stages in childhood and adolescence and not solely adolescence alone. Interestingly, the protective factors against SIB are different at adolescence to that at childhood.

Adolescents with good communication skills seemed to display less SIB – suggesting a potentially communication motive for SIB observed.

The severity of autism was also associated with other challenging behaviours, including irritability, hyperactivity and impulsivity. This suggests also that SIB may be linked to motor-impulse difficulties or lack of inhibitions.

Finally, it is important to note the relationships between high SIB in adolescents and poorer reported quality of life for parents.

Additionally, results also showed that the amount of external intervention (recorded in hours of support given) showed no significance on the incidence of SIB.

It is clear from this study more research in this area is needed, but also, suggestions for interventions, for both adolescents and parents, would be useful.

• How can we improve support at this time of life for all parties?
• Can we work to reduce incidence of SIB based on these findings?
• Could we even work to prevent SIB increasing during adolescence?

These are questions that surely would need consideration in any future findings.

Links

Primary paper

Rattaz, C., Michelon, C., and Baghdadli, A. (2015) Symptom severity as a risk factor for self-injurious behaviours in adolescents with autism spectrum disorders. J Intellect Disabil Res, 59: 730–741 [abstract]

Other references

Lord C., Rutter M. & Couteur A. (1994) Autism diagnostic interview-revised: A revised version of a diagnostic interview for caregivers of individuals with possible pervasive developmental disorders. Journal of Autism and Developmental Disorders 24, 659–85.

Rojahn J. & Helsel W. J. (1991) The Aberrant Behavior Checklist with children and adolescents with dual diagnosis. Journal of Autism and Developmental Disorders 21, 17–28.

Schopler E., Reichler R. & Renner B. (1988) The Children Autism Rating Scale (CARS), pp. 1–6. Western Psychological Services, Los Angeles, CA.

Sparrow S. S., Balla D. A. & Cicchetti D. V. (1984) The Vineland Adaptive Behavior Scales. America Guidance Service, Circle Pines, MN.