The Use of Transcranial Direct Current Stimulation (tDCS) in Adults With Developmental Disabilities

The Use of Transcranial Direct Current Stimulation (tDCS) to Reduce Impulsivity and Aggression in Adults With Developmental Disabilities: The tDCS-RIADD Randomized Controlled Trial Protocol

Aggressive behaviours are highly prevalent among people with developmental disabilities, both in community and inpatient or residential settings, with adverse consequences for the individuals involved and others. Some predictive factors, particularly impulsivity, are dynamic with neurobiological underpinnings, and as such amenable to change or neuromodulation using non-invasive brain stimulation techniques. With this in mind, we designed an experimental protocol to determine the efficacy of transcranial Direct Current Stimulation (tDCS) as a non-invasive brain stimulation technique to reduce impulsivity and aggression associated with developmental disability.

This study aims to assess the efficacy of anodal tDCS in modulating Rapid Response Impulsivity (RRI) and reducing incidents of aggression in people with developmental disabilities is residential or hospital settings. Using a single blind, parallel arms, randomized controlled trial design, adults (n=60) aged 18 to 65 with developmental disabilities, who have a history of impulsivity leading to aggression, will be randomised to receive either repetitive anodal or sham tDCS. Enrolled participants will receive either three treatment sessions of tDCS or sham tDCS. Behavioural and impulsivity will be measured before and immediately after treatment, one week, and one month after treatment end. Data will be analysed in SPSS using repeated measures ANOVA.

Inclusion Criteria:

• Adults aged 18-64 years
• Diagnosis of a developmental disability
• History of one or more incidents of aggression in the last month
• Consent to participate in the trial by the individual or their Substitute Decision Maker

Exclusion Criteria:

• History of epilepsy or seizures
• History of acquired brain injury
• Having metal in the brain/skull, e.g. splinters, fragments or clips
• Having a cochlear implant
• Having an implanted neuro-stimulator (e.g. direct brain stimulation, epidural/subdural stimulation, vagal nerve stimulation)
• History of brain surgery of procedure
• History of severe adverse reaction to tDCS
• Having a cardiac pacemaker or intracardiac lines
• Current alcohol or drug misuse
• Having a sensitive scalp