Paper showing that completing most psychological studies is less distressing than daily life I once read a study that compared the level of distress of completing a psychological study to other activities in daily life (e.g., commuting to work; interacting with colleagues; watching tv; or something like that).

The paper is a good reference when you are applying for ethics approval.

Does anyone know the reference?
Or perhaps there are a few such articles?
The article could be

How distressing is it to participate in medical research? A calibration study using an everyday events questionnaire. 

Petrie, K. J., Faasse, K., Notman, T. A., &amp; O'Carroll, R. (2013). 
JRSM short reports, 4, 1-7.

PDF available