Questionnaire No. 2

Prior to the questionnaire No. 2

In the eighteen months separating the questionnaire No. 1 and No. 2, participants were invited twice to update their contact details online (a hard copy was sent by post if wished).

These updates allowed us to keep in touch with participants and seeked to:

• guarantee an ongoing participation, so that the study is the most representative possible;
• make sure that participants receive the letters and/or emails, including incentives. It is most important that participants receive vouchers at the correct address!

The questionnaire No. 2

This stage consisted in filling in another questionnaire online (a hard copy was sent by post if wished) during about 45 - 60 minutes about 18 months after the 1^st questionnaire.

This questionnaire was very similar to the first questionnaire. It also was about the participants' socioprofessional and family background, their consumption of alcohol, cannabis and other drugs, as well as their personality and behavioral addictions like, for example, gambling.

The participation was rewarded with a gift voucher, which was sent shortly after the questionnaire was filled in.

Participants were invited to fill in this questionnaire by email. In this email, they found a personal link to the online questionnaire. Those who prefered to fill in a hard copy could get it by post with a postage prepaid envelope.

Take a look at the questionnaire No. 2