John W. Herdman is the owner of Parallels in Lincoln, Nebraska. Parallels is a private out-patient mental health and substance use treatment clinic.

His therapy orientation is cognitive-behavioral and after 46+ years of working with substance abusers using this therapy he has published a workbook called A Rational Workbook for Change. This new workbook builds on his two previous workbooks, A Rational Workbook for Addictions and A Rational Workbook for Anger: Help for Those with a Co-Occurring Substance Use Disorder, co-authored with Theodore Burns.