This invention encompasses compounds of formulas (I), where R1, R3, R4, R6, X, Y, and Z and T are variables; and M is α or β, where R2 is a variable; or R1 and R2 together may represent -(CH2)n1 where n1 is 1, 2, or 3. These compounds are highly selective partial agonists or antagonists at brain dopamine receptor subtypes or prodrugs thereof and are useful in the diagnosis and treatment of affective disorders such as schizophrenia and depression as well as certain movement disorders such as Parkinsonism. Furthermore compounds of this invention may be useful in treating the extraparamidyl side effects associated with the use of conventional neuroleptic agents.