One of the most obvious and direct ways to reach the public with medical research is through the performance of trials and the development of new therapies for the benefit for patients and relatives. In Aggressotype, we pursue two very different approaches, the first one being a biofeedback trial with children and the second one being a medication-based treatment of aggression in young prisoners with ADHD.


Current behavioural and pharmacological treatments of paediatric aggression are still limited and lack both innovation as well as personalization. One of our research teams aims to meet these needs by targeting the core brain and autonomous functions such as arousal dysregulation.

By establishing the most consistent arousal markers, we will be able to more reliably distinguish between instrumental and impulsive aggression, which paves the way for better and individualized treatment. Through innovative biofeedback training protocols, young patients will learn how to self-regulate their individual arousal level (up- or downwards), depending on their “aggressotype”. This personalized, deficit-specific biofeedback training for both forms of aggression will then be evaluated in a controlled multicenter trial.

Lacking previous arousal biofeedback trials on aggression, we will test different arousal measures such as skin conductance level or EEG and will develop age-appropriate simple feedback displays, plus feedback through more naturalistic virtual reality gaming environments, and transfer displays without feedback. A six month follow-up will assess sustained clinical effects, while particular care will be taken to obtain reliable blinded outcome ratings for total and subtype specific aggression scores.

Treatment of aggression in young male prisoners with ADHD

ADHD is associated with impulsive aggression: The most common forms of severe persistent aggression are linked to the development of conduct disorder, with emotionally labile and impulsive traits, most commonly in children who meet criteria for attention-deficit/hyperactivity disorder (ADHD). Recently, the link between ADHD and criminal behaviour, including aggressive or violent acts, was demonstrated in a large epidemiological study of 25,656 patients with ADHD [30]. Not only were criminal convictions 4-fold higher in ADHD compared to controls, but ADHD drug treatments (stimulants and atomoxetine) led to 30-40% reductions in criminal convictions. Our own research found a 6-fold increase in violent and aggressive incidents among male prisoners, which was associated with current ADHD, even after controlling for antisocial personality disorder [42 ]. These and other data suggest that impulsive aggression is often associated with ADHD in offenders, potentially mediated by difficulties with control of impulsive behaviour and emotional dysregulation (irritable and aggressive moods) [20] [21].

These findings suggest that ADHD plays a key role in the development of aggression in a significant subgroup of young offenders, and suggest that drug treatments for ADHD may be effective in reducing aggressive behaviour. Furthermore, we know that medications for ADHD (such as methylphenidate; Ritalin, Concerta, Equasym and Medikinet) reduce emotional instability in adults with ADHD, with similar effect to that seen on the core ADHD symptoms of inattention, hyperactivity and impulsivity [43] [44].

Despite these observations and the high rates of young adult offenders with ADHD and impulsive forms of aggression within the criminal justice system [29], ADHD is rarely diagnosed and treated among young offenders across Europe. Furthermore, there has been no systematic evaluation in young adult offender samples, of the effects of methylphenidate, the first line treatment of ADHD [1], on aggressive or violent behaviour.

Clinical trial of Concerta XL in adult offenders with ADHD (the CIAO study): We are conducting a clinical trial of Concerta XL, a long acting formulation of methylphenidate, on aggression in young adult prisoners. The prison we are working with, in South East London (UK), holds short to medium term prisoners between the ages of 18-30. The overall aim of the study is to evaluate the effectiveness of treatment on aggression, measured by the number or recorded events of aggression, as well as the participants’ attitudes towards violence and reports of behaviour from prison staff. In addition, we will evaluate engagement with education and rehabilitation programs and changes in ADHD symptoms and mood instability. This is one of the first programs of research to systematically diagnose and treat young adult prisoners for ADHD in Europe.

Preliminary findings: We have screened more than 1,200 offenders with ADHD and found that 20% meet the diagnostic criteria for ADHD. This means that they had ADHD as children and currently have severe and impairing levels of inattention, hyperactivity and impulsivity as adults. We also see very high rates of emotional instability and aggression within this group of prisoners. Around half of the prisoners with ADHD - that is 10% of the entire prison population – have taken part in the study.  We see significant improvements across a range of outcomes. As expected we see significant reductions in inattention, hyperactivity and impulsivity, based on the participant reports of their symptoms and behaviour. We also see that they have greater control over their emotional and mood symptoms, so they are calmer and less likely to overreact when provoked or feel frustrated. They describe reductions in violent thoughts on a scale called the Maudsley Violence Questionnaire, which is known to be related to reduction in aggressive behaviour. These changes appear to occur rapidly, with most of the improvements seen within the first 5 weeks of treatment.

Future directions: The potential impact on individuals and society could be considerable, if it can be shown that treating ADHD in prisoners can reduce rates of aggression and criminal behaviour more generally. There may be economic savings to the criminal justice system, particularly if effective treatment can keep individuals out of prison and in work. It is only too common that young adult offenders repeat their criminal behaviour, or are unable to be supervised adequately in the community, and repeatedly return to prison. There are the obvious costs to victims and the families of offenders. In order to provide definitive data on the benefits of treating ADHD in prisoners, we envisage the following additional steps:

This initial study is an open pilot study, so we will not be able to separate out any benefits of the medical treatment from the more general benefits that arise from taking part in a carefully supervised treatment program. We will therefore be seeking additional funding to enable us to conduct a similar study with a blinded placebo group.

Medical treatment for ADHD is unlikely to be sufficient to reduce aggressive behaviour for all prisoners with ADHD. However one of the benefits of treating ADHD is the increased ability to engage and participate effectively in educational programs. We therefore plan to evaluate a program of psychological treatment that will run alongside the medical treatment program.

The major benefits to society are not within the prison but rather when prisoners are released back into society. For this reason we plan to extend the program of research, to evaluate the potential benefits to individuals in the community outside of the prison. We will therefore work towards establishing a program of treatment and support for offenders with ADHD in the community, with evaluation of the impact of treatment on aggression and other forms of criminal behaviour, as well as functioning in family, social, academic, occupational and mental health outcomes.