> The entire science is based on the patients self reported feelings or the psychatrists feeling of how someone else is feeling.

This study is showing that THC, CBD, blends, or cannabis do not improve self-reported feelings over the long term.

You can use pedantry and wordplay all you want, but no matter how we look at this study it does not show positive effects.

> What you're saying is something else, that drugs can produce long term harm despite short term improvements

Recreational drugs make you feel good temporarily. That's literally why people do them.

They also cause harm when abused.

These are all obvious and well known facts.

> How do amphetamines treat the source of ADHD?

By giving a patient the ability & skills to establish a less dopamine-seeking lifestyle while temporarily relieving them of the deficit.

Its use is supposed to be coupled with therapy and/or coaching (e.g. https://www.thriveemerge.com) to ensure that the patient isn't just using it as a lifelong crutch.

That's how it's supposed to be done. This approach is more effective in children for obvious reasons. Persons diagnosed later in life are therefore more likely to require it permanently.

As doctors Psychiatry should definitely look at imaging of the brain.

One place I'm aware of that works from imaging as well is Amen Clinics in the US.

> How do amphetamines treat the source of ADHD?

By increasing the baseline dopamine? I think the biological mechanisms for the ADHD treatment are more-or-less clear at this point.

Not so much with depression, though.