Children with mental problems often have problems at school and require additional support compared to children without mental problems. This is often associated with high costs for society and for the education sector in particular. Considering these costs in policy decisions regarding funding of mental health services is crucial. However, up until now these costs have often been disregarded, which does not allow for assessing the total societal impact of mental problems. This thesis investigated the methods for measuring broader societal impacts of mental problems, particularly focusing on the impact on the education sector. This dissertation includes studies that review existing evidence and propose new standardised methods for the inclu...