Up Next
Back to Show
PBS News Hour
Scientists race to learn how marijuana affects the brain
As national attitudes and laws around cannabis use have evolved, so have the commercially grown strains of the plant. Some marijuana varieties today contain levels of THC, the drug’s psychoactive compound, as high as 50 percent, compared to around 5 percent a generation ago. But as science correspondent Miles O'Brien reports, the effects of cannabis on the human brain are still relatively unknown.
Support Provided By
26:45
November 1, 2025 - PBS News Weekend full episode
57:46
October 31, 2025 - PBS News Hour full episode
57:46
October 30, 2025 - PBS News Hour full episode
57:46
October 29, 2025 - PBS News Hour full episode
57:46
October 28, 2025 - PBS News Hour full episode
57:46
October 27, 2025 - PBS News Hour full episode
26:45
October 26, 2025 - PBS News Weekend full episode
26:45
October 25, 2025 - PBS News Weekend full episode
57:46
October 24, 2025 - PBS News Hour full episode
56:42
October 23, 2025 - PBS News Hour full episode
57:46
October 22, 2025 - PBS News Hour full episode
57:46
October 21, 2025 - PBS News Hour full episode