Ethics approval and consent to participate
The study was approved by the local Research Ethics Committee in Uppsala (Dnr 2014/530) and the Swedish Medical Products Agency (EudraCT 2014–005045-53), and the protocols were conducted in accordance with the Declaration of Helsinki. The trial was registered at ClinicalTrials.gov NCT02473185, before involvement of the first patient. Participation in the study was voluntary and the adults were provided with a written informed consent after receiving a complete description of the study and were informed on their right to retract from the study at any chosen time. The participants were informed for ethical reasons when included in the study, that in one session they would receive an active substance and in the other session they would receive placebo in randomized order.