Provided herein are compounds of the formulae IA IF. These compounds are tetrahydroisoquinolines of the following structure: ##STR00001## wherein R.sup.1 R.sup.8 for compounds of each of the formulae IA, IB, IC, ID, IE and IF are as described herein. Said compounds are particularly useful in the treatment of various neurological and psychiatric disorders, e.g., ADHD.