Fox News senior medical analyst Dr. Marc Siegel discusses new research that casts doubt on cannabis benefits and highlights increased mental health risks, especially for teenagers. Modern marijuana, with 70-90% THC potency, is linked to higher rates of PTSD, anxiety, depression, ADHD, and bipolar disorder. Usage among Americans aged 12 and older has skyrocketed by 180% since the early 2000s, leading to concerns about addiction and health issues.