This research study is looking to recruit adults 18 years of age or older who are using stimulants (e.g., Cocaine, Methamphetamines, Amphetamines) and currently in treatment or thinking about starting treatment within the next 12 months. If you agree to participate in the study, you will be asked to attend an in-person screening visit to fill out questionnaires, discuss your alcohol and drug use history, and complete a urine drug screen. If you meet our eligibility criteria, you will then be asked to come in for a second study visit to complete an electronic version of StUDSS over Zoom with a trained interview. You will receive up to $100 in compensation for the study ($25 for the screening visit and $75 for the one-on-one interview). In total, these visits will take approximately 3 hours to complete.