A committee on the standardization of questionnaires invited 93 Dutch researchers in the field of clinical psychiatry and the Dutch branches of 15 pharmaceutical industries to send copies of the depression questionnaires they used. 53% responded, 33 responders returned 65 depression questionnaires. The following questionnaires were received more than once: The Hamilton Depression Questionnaire (22 times), the Zung Depression Scale (14 times), The Montgomery-Åsberg Depression Scale (3 times), the SCL-90 (4 times) and the Newcastle Scales (3 times). With the exception of the last two scales different and very divergent versions of the scales were sent. On a subsequently held consensus-meeting it was agreed to use only one version of each scale. It was also decided which version that will be. The second part of the article deals with the criteria and data used during the consensusmeeting and with the results.