Further validity evidence for the dimensions of change in therapeutic community treatment instrument. 
Recent research efforts have focused on assessing the therapeutic community (TC) treatment process.  The current article examines the validity of the client self-report Dimensions of Change Instrument (DCI) treatment process measure, by confirming its factor structure and examining each subscale's relationship with time in treatment, scales from an existing process assessment, and mental and physical health status.  Participants were 511 adult and adolescent residential TC clients.  The factor structure of the DCI replicated with satisfactory fit.  The pattern of associations between DCI subscales and criterion measures was largely as expected, providing initial concurrent and discriminant validity evidence for the DCI.