The BRAIN Lab focuses on the psycho-neurobiological mechanisms underlying cognitive, affective, and stress-associated aspects of decision-making and impulsivity—specifically related to substance use disorders and concurrent mental disorders. Aspects of decision-making may be important in mediating vulnerability towards the initiation and maintenance of behaviours such as drug addiction, and mental disorders. A better understanding and better models of the brain/mind are essential for rational treatment development. Promising new approaches are needed desperately to help reduce addiction and mental health associated suffering. The BRAIN Lab studies new promising approaches including retraining of approach habits, new electrophysiological treatments (e.g. TMS) and new integrated psychotherapy/psychedelic interventions. We use subjective assessments, behavioural testing and neuroimaging to study psychopathology and the outcome of interventions. The aim is to improve our understanding and to ultimately facilitate better interventions and better outcomes for individuals suffering from substance use and mental disorders.