Nes, R. B., Czajkowski, N. O., Røysamb, E., Ørstavik, R. E., Tambs, K., & Reichborn-kjennerud, T. (2013). Major depression and life satisfaction : A population-based twin study. Journal of Affective Disorders, 144(1–2), 51–58. https://doi.org/10.1016/j.jad.2012.05.060