Offspring of parents with psychotic- and major mood disorders have an increased risk of developing a severe mental illness themselves. Premorbid cognitive and psychopathological deficits may be related to structural, neurochemical and functional brain abnormalities, underlining the neurobiological basis of these severe mental disorders. These early antecedents including anxiety- and depressive symptoms, manic/psychotic like experiences and cognitive deficits precede and predict the development of these illnesses, but are non-specific. Familial high risk studies of children with parents with mental illnesses can identify early precursors of mental illness, and offer more insight about trajectories of both symptom dimensions, cognition, structural/functional brain differences, environmental stressors and thereby identify possibilities for intervention in the pre-morbid phase. Indeed, early identification and detection is necessary if we want improve the prevention and treatment of severe mental illnesses. The objective of this symposium is to present and discuss new data from six international studies (Denmark, The Netherlands, Spain and Switzerland) describing the psychopathology, neuroimaging, cognitive and environmental findings in offspring of parents with psychotic- and major mood disorders. 1) The Danish group will present the plans for the VIA11 study based on a fMRI imaging literature review in first degree relatives of schizophrenia patients; 2) The Spanish group will present on the clinical, neurocognitive and structural neuroimaging assessment in their Bipolar and Schizophrenia Young Offspring Study (BASYS); 3) The Dutch group will present the psychopathology and structural brain findings from their Bipolar and Schizophrenia Offspring Study (DBSOS); 4) The Swiss group will present on cognitive performance in bipolar patients and their children and 5) on psychopathology of young children aged 4 to 7 of parents with bipolar or major depressive disorder; 6) The Dutch group will present on the role of family functioning and childhood trauma in the development of psychopathology in bipolar offspring, during 12 year follow-up. Conclusion: The convergent findings of these international offspring studies add to the construction of specific risk profiles in these high risk populations which can be used in early identification and prevention programs.