Self Injurious Behaviour (SIB)

SIB refers to a class of behaviors which the individual inflicts upon his/herself that have the potential to result in physical injury, more specifically tissue damage. SIB may manifest in numerous ways, including but not limited to head banging, self-cutting, self-choking, self-biting, self-scratching, hair yanking, and hand mouthing^[1].

In children with Autistic Spectrum Disrder, SIB tends to be classified as “stereotyped SIB” as opposed to the “impulsive SIB” that is habitual in nature as seen in serious psychiatric illness or even in typically developing adolescents and adults.

• Lifetime prevalence of 50% in children with ASD
• The most common forms of SIB in those with ASD are self-biting, self-scratching, skin picking or pinching, self-punching, and head banging; less common but still occurring types of SIB in persons with ASD include eye pressing or gouging, pulling one’s own hair, teeth, or fingernails, dislocation of joints (eg, fingers, periorbital area, mandible), pica, and knee-to-head hitting^[2].
• There is a direct link between problem behaviors and a diagnosis of intellectual disability, with around 25% of individuals with intellectual disability experiencing self-injurious behavior.
• Problem behaviors can sometimes be indicative of coexisting psychiatric disorders in individuals with intellectual disabilities, as well as those with autism spectrum disorders.

Conducting a functional behavior assessment (FBA) can help identify any behavioral factors that may be contributing to the self-injurious behavior (SIB). Additionally, it is important to explore various behavior-based intervention techniques that can be used to reduce SIB. A Functional Behavior Assessment (FBA) is based on the understanding that behaviors have a purpose in communicating a message for an individual^[3]. The purpose of a behavior is determined by the specific outcome it reinforces.Functional assessment involves gathering information about the events and outcomes related to a particular behavior, with the goal of understanding the purpose that behavior serves for the person.After identifying the antecedents and consequences that maintain SIB through an FBA, it is possible to hypothesize about the function(s) of the behavior(s). Research indicates that behavior serves various purposes, including seeking social attention, obtaining tangible rewards, avoiding certain activities or situations, and seeking internal stimulation.

The behavioural theory of SIB suggests that these behaviors are learned and provide the individual with some form of reinforcement^[1].The reinforcement can come from the individual's environment or from their own body, either externally or internally. At times, SIB can fulfill a social-communicative purpose, leading to alterations in the person's surroundings. For instance, SIB can lead to a decrease in the demands placed on a person, allowing them to obtain something they want or receive attention from others. Therefore, the SIB can persist over time due to positive or negative reinforcement, making it difficult to alter the behaviors without addressing the environmental factors. Identifying the factors that reinforce self-injurious behavior (SIB) in individuals requires conducting appropriate assessments. It is important to understand the unique reinforcement sources that motivate SIB for each person.

Several parent or caregiver administered instruments currently exist which assess for challenging behaviors in the general population and those with developmental disorders.

• Aberrant Behavior Checklist^[4]
• Behavior Problems Inventory-01^[5]
• Children’s Scale of Hostility and Aggression: Reactive/Proactive^[6]
• Developmental Behavior Checklist^[7]
• Nisonger Child Behavior Rating Form^[8]

Exclusively for ASD

• Self-Injury Trauma (SIT) scale^[9]
• PDD Behavior Inventory^[10]
• Autism Spectrum Disorders – Behavior Problems for Children^[11]
• Baby and Infant Screen for Children with aUtIsm Traits (BISCUIT)-Part 3^[12]

• Antecedent-based intervention strategies
• Reinforcement-based intervention strategies
• Extinction-based intervention strategies
• Punishment-based intervention strategies

Antecedent-based intervention strategies There is a wide range of antecedent interventions that have proven to be effective in changing the factors that cause self-injurious behavior in individuals with Autism Spectrum Disorder (ASD).

• changing a child’s schedule to avoid, minimize or rearrange challenging parts of the day
• Manipulation of sleep schedules
  • faded bedtime routine to decrease the number of night-time awakenings and associated SIB
  • inclusion of a nap after a night of reduced sleep that had been related to high rates of SIB
• adaptation of demands that may be precursors to SIB. Interspersing simple, high compliance demands amongst more difficult, lower compliance demands

Reinforcement-based intervention strategies

Reinforcement is the application or removal of stimuli that results in an increase in behavior over time. Noncontingent reinforcement (NCR) involves the presentation of the reinforcing consequence for the problem behavior on a time-based and response-independent schedule.

if SIB is found to be maintained by social attention, then the reinforcer stimulus provided would be positive social attention from adults or peers. If the behavior is maintained by negative reinforcement, as is the case in escape-maintained behavior, then the reinforcer stimulus provided would be escape (ie, break) from demands. Noncontingent negative reinforcement may be composed of providing breaks from demands to an individual with SIB on a fixed schedule so that breaks are no longer provided contingent on SIB.

Extinction-based intervention strategies

During extinction procedures, the reinforcing consequence that was previously maintaining the SIB is stopped, thereby removing the motivation for the problem behavior. or example, in a case of SIB maintained by social attention, planned ignoring can be employed. For SIB maintained by escape from demands, escape extinction is the appropriate extinction technique to employ.

In SIB that is maintained by automatic reinforcement (hitting the head for e.g) the behavior itself leads to positive outcomes for the individual, rather than relying on external factors that may be easier to manipulate. When dealing with SIB maintained by automatic reinforcement, the intervention focuses on preventing the sensory experience caused by the behavior. Protective equipment like helmets, gloves, or arm restraints is commonly used to carry out sensory extinction.

Protective gear is commonly employed in instances of severe SIB to minimize the risk of physical harm.However, wearing protective equipment can also help decrease sensory stimulation during and after an episode of SIB, acting as a way to stop the behavior.The physical restraint employed should limit movement as little as possible while preventing self-injurious behavior.It is important to have a clear plan in place from the beginning of treatment on how to gradually reduce the use of manual restraints. Another effective option for treating automatically-maintained SIB is using a competing sensory stimulus that replicates the sensory experience of SIB. For example, a hand massager can be used to mimic the effects of hand mouthing or biting.By offering uninterrupted access to these stimuli, it may reduce the desire to seek reinforcement through self-injurious behavior^[13].

Punishment-based intervention strategies

Punishment is the application or removal of stimuli in order to decrease the likelihood that a particular behavior will occur again in the future. Some of the most commonly studied punishments are: physical restraint, “response reduction” procedures (eg, time-out, facial screens), and the application of aversive stimuli (eg, water misting, aversive odors, brief contingent electric shock).