• The causal role of smoking in anxiety and depression: a Mendelian randomization analysis of the HUNT study 

      Bjørngaard, Johan Håkon; Gunnell, David; Gabrielsen, Maiken Elvestad; Davey Smith, George; Skorpen, Frank; Krokan, Hans Einar; Vatten, Lars Johan; Romundstad, Pål Richard (Journal article; Peer reviewed, 2013)
      Cigarette smoking is strongly associated with mental illness but the causal direction of the association is uncertain. We investigated the causal relationship between smoking and symptoms of anxiety and depression in the ...