General goal

The goal of IMAGEN is to use existing genomic and neurobiological information and establish new neuroimaging approaches to better understand fundamental functions of the brain, reinforcer sensitivity and executive control, and their implications for normal brain function and brain pathologies.    

Impact for the EU

Mental disorders are a major health problem with a lifetime prevalence of more than 25% (WHO report 2001). According to the WHO, 25% of the general population will have one or more mental disorders during their lifetime: this is a major health problem.In Europe, 34 million people in 2004 had addiction, affective and anxiety disorders which amounted to an annual cost to society of at least 204 billion Euros. 

Concept of IMAGEN

• The analysis of genetic factors in mental disorders has been hampered by their poor, descriptive classification, grouping heterogeneous disorders under a single diagnostic category. The use of brain imaging methods, such as Magnetic Resonance Imaging (MRI), makes it possible to understand brain mechanisms that underlie the various disorders and link them to genetic variation and behavioural changes that are characteristic of disease processes.
• Recent advances in genomics (the study of genes and their functions) provide new opportunities to identify the genes that influence these processes, and to examine their interaction with environmental factors.
• One of the major challenges addressed in this project is to assemble key biological resources and brain imaging data from human volunteers and in animal models that is required to take advantage of these opportunities.
• We will use the biological resources and data collected here to identify major genetic determinants of core process of motivational and emotional behaviours in order to understand abnormal changes in these processes that lead to many mental disorders.
• The goals of assembling and investigating these materials can be achieved only through a large, pan-disciplinary collaboration that integrates groups specialised in neuroimaging, human genetics and behaviour.

Scientific Background

A fundamental function of the brain is to evaluate the motivational and emotional significance of events and to adapt the behaviour of the organism accordingly. The processing of reinforcers, such as rewards and punishment and emotional cues is a central component of our behaviour. The quality of the reinforcers affects behavioural choice in decision making processes, thus recruiting executive processes to optimise the behavioural outcome. Responsivity to reinforcing feedback and executive control of behaviour to optimize that reinforcing feedback is necessary for survival. Core processes of reinforcer sensitivity and behavioural control include impulsivity, sensitivity to and conditionability of reward and punishment, novelty seeking and attentional modulation of emotional responses. Abnormal changes in these behaviours are at the core of many brain disorders with a major public health impact, including addiction, affective and anxiety disorders eating disorders, attention deficit and antisocial personality disorder.

Developmental processes in adolescence are critical for the establishment of behavioural control and normal adult brain function. These processes render the adolescent brain particularly vulnerable to disruption by drugs and stress, while simultaneously allowing for increased risk taking. A recent study emphasised the vulnerability of this developmental period by showing that adolescents younger than 15 with multiple problem behaviour had a lifetime rate of substance use disorders, antisocial personality disorders and depressive disorders of up to 90%, 90% and 58%, respectively.