The effect that genes have on our brain depends on our age, researchers say. It has been known for a number of years that particular genetic variations are of importance for the functioning of neural circuits in the brain. Just how these effects differ in the various stages of life has until recently not been fully understood. This international study has been able to demonstrate that genetic variations at different times in our lives can actually have opposite effects on the brain, which provides an explanation for the differences that clinicians observe in the psychiatric symptoms and response to medications of adolescents and adults.