Aggression, overt behaviour with the intention of inflicting physical damage, is a physiological trait with important roles throughout evolution, both in defence and predation. When expressed in humans in the wrong context however, aggression leads to social maladjustment and crime.

Maladaptive aggression is commonly observed across childhood conduct (disruptive behavioural) disorders, in particular in Attention Deficit/Hyperactivity Disorder (ADHD) and Conduct Disorder (CD). Aggression in these disorders is a heterogeneous trait, which scientists have tried to subdivide in diverse ways. Such subdivision is a prerequisite for the development of effective prevention and treatment strategies, as currently available treatment options for maladaptive aggressive behaviour have limited efficacy.

The most promising candidate subdivision, derived from animal studies, defines an emotionally labile, reactive impulsive and a low emotional, instrumental (‘predatory’) subtype [39]. Evidence from human studies supports this subdivision (e.g.,[40]), which may finally open up possibilities for developing effective prevention and treatment strategies for vulnerable children.

The main aims of the Aggressotype programme are:

• to gain new insights into the mechanisms underlying pathological aggression by improving the subtyping of aggression and building a knowledge chain for the aggression aetiology from the molecular level via cellular, brain-network and cognitive levels to behaviour;
• to translate our preclinical findings into predictive, preventive and therapeutic strategies for the benefit of vulnerable patients with paediatric conduct disorders.

Aggressotype concentrates its work on children most vulnerable to maladaptive aggression, i.e. those with ADHD and those with CD, who are particularly prone to impulsive and instrumental types of aggression, as well as on individuals from the general population. Longitudinal studies and cross-sectional studies in young adults inform us about the developmental course and adult outcome of aggression subtypes. These studies are complemented by parallelized animal studies.

Aggressotype uses molecular, neurobiology and neural systems approaches to clarify the mechanistic communalities and differences underlying impulsive and instrumental subtypes of pathological aggression.

Only through such rigorous characterisation approaches can new horizons for individualising prevention of pathological aggression and improving and personalising aggression treatment be opened up. The objectives and approaches to be used in the Aggressotype programme are summarized in this diagram: