CNN’s Dr. Sanjay Gupta is back, and he’s laying it all on the table this time around.

In “Weed 3,” we are eyewitnesses to a revolution in full swing. You will ride along with us for the dawn of the first federally approved clinical study on the use of marijuana for PTSD. You will meet patients such as Sean Kiernan, an accomplished investment banker, and Amelia Taylor, a stay-at-home mom.

They are the remarkable and surprising faces of this revolution — smart, successful and suffering — unwilling to accept the fact that commonly prescribed medications often used to treat PTSD can be worse than the underlying disorder itself. Sean Kiernan nearly died, trying to get better.

You will see what weed really does to your brain, in crystal clear images. This time around, you will hear from the heads of government agencies earnestly sharing their point of view, both Democratic and Republican senators, and even the President of the United States.

This is what a revolution looks like.

We also recommend that you view Dr. Gupta’s previous documentaries Weed and Weed 2.