We examine psychological distress (PD) in young adult Ecstasy users in relation to age of initiation and frequency of use of Ecstasy, cannabis, alcohol, and tobacco. Using two Australian community samples, we assess whether different sampling methods produce comparable estimates of these associations. The Natural History Study of Drug Use (NHSDU; N = 339) in 2009 used population sampling and the 2009 Ecstasy and Related Drug Reporting System (EDRS; N = 359) used purposive sampling. Participants, aged 19-23 years, were recurrent Ecstasy users. PD was assessed using Kessler 10 in the EDRS and Hospital Anxiety Depression Scale in the NHSDU. In both samples, PD was associated with daily tobacco use and early drug initiation, but not frequent Ecstasy use. One-third smoke tobacco daily. Study limitations and implications are noted.