Looking back, 2015 was a landmark year for the world of marijuana politics, healthcare and culture. Here are five people who changed the conversation surrounding cannabis in a positive way by challenging stereotypes, wedding legalization to social justice and standing up for patients' rights.

1. Bernie Sanders

At a campaign event in Fairfax, Virginia on Oct. 28, Vermont Senator Bernie Sanders called for an end to the War on Drugs and repeal the federal prohibition of cannabis. Those comments made him the most progressive 2016 Democratic presidential candidate on the cannabis issue. And his stances earned him the Marijuana Policy Project's highest grade among his fellow Democrat and rival Republican presidential hopefuls.

2. Justin Trudeau

Canadian Prime Minister Justin Trudeau has pledged to legalize cannabis nationwide. But he isn't doing it for the money: "there is potential for a bit of revenue on that, but we're certainly not looking for a windfall," he told reporters on Dec. 17.

Instead, he wants to use legalization to improve public safety:

"Right now Canada has the highest use of marijuana by underage people in the developed world. We need to make sure we're keeping our kids safe and keeping our communities safe by removing the black market and the criminal gangs and the street organizations from it."

3. Coltyn Turner

DEA head Chuck Rosenberg caused controversy last November when he called medical marijuana a joke. Activists quickly condemned his comments, and many urged President Obama to fire Rosenberg.

But the most powerful response came from Coltyn Turner, a Colorado teen who takes cannabis oil to treat Crohn's disease. In this short video, Turner asked Rosenberg a simple but poignant question:

#imnotajoke. 20 months in remission from Crohns, RA and Lupus because of MARIJUANA!! Hey Chuck! Coltyn Turner is NOT a joke!! Cannabis is medicine! #resignchuck #coltynscrue

Posted by Wendy Turner on Thursday, November 19, 2015

4. Snoop Dogg

Saying Snoop Dogg has had a tremendous impact on cannabis culture is like saying tires are handy for driving. In 2015, the Doggfather upped his game by launching the website Merry Jane and adding style to cannabis packaging with his line of flower, edibles and concentrates called Leafs By Snoop:

5. Mindy Segal

She's an award-winning pastry chef who owns the restaurant Mindy's Hot Chocolate in Chicago. In December, she announced she's teaming up with Cresco Labs to make marijuana-infused treats for Illinois and other states where marijuana is legal for medicinal or recreational use.

"I'm trying to elevate the industry," Segal told the Associated Press. Instead of baking typical hash brownies, she's working on salted toffee, smoked almonds and dark chocolate brittles.

"We're going to come up with recipes that are portioned and dosed properly," she added. "So we're healing, making people have appetites, not have pain."

And based on her previous work, she shouldn't have much trouble whetting her customers' appetites:

Banner Image by Flickr User Benjamin Kerensa