Amen's claim to fame is using SPECT imaging for diagnosis. Has any other scientist/clinician reproduced Amen's claims that certain imaging results correspond with precise ADHD symptoms? I'm not aware that has happened. If it's not reproducible, it's not science or medicine. Also, just because he has publications doesn't legitimize his claims for use in clinic.
I mentioned his clinic using traditional ADHD treatments because those actually do the work to help patients. Afterward, those patients might associate the benefits of the treatment with the imaging, even if they could have had the same outcome with treatment alone.