[ktaylora]

You can try the experiment on yourself. Find capsules of flax seed oil that look like capsules of CBD oil. Have someone place a one-to-three week supply of each in separate envelopes and take them twice daily. Score your anxiety level each morning until all the tabs are gone. Estimate your average anxiety level each week. Then ask the person to reveal the envelopes to you and see if you can find a measurable difference between the treatments.

[Canadauni]

To be really sure it would be a good idea to have one person enclose the tablets in the envelopes and a different person to administer them to you.

But I suspect that there might be other factors here that might influence your study design. Mostly because neurotransmitters are super complicated.