Complex sentence: This form of therapy, including diagnosis and accompanying parenting techniques, is scientifically unvalidated and is not considered to be part of mainstream psychology or, despite its name, to be based on attachment theory, with which it is considered incompatible.
Split into simpler sentences: This form of "therapy", including diagnosis and accompanying parenting techniques, is not scientifically validated, nor is it considered to be part of mainstream psychology. It is, despite its name, not based on attachment theory, with which it is considered incompatible.