A new study explores the cause of seasonal affective disorder (SAD). People with SAD process significantly less serotonin in winter than summer. Gayle King reports. Source

A man from Bulgaria who was paralyzed below the chest can now walk again, thanks to a transplant of cells from his nose to his spinal cord. Charlie Rose reports. Source

Action star Keanu Reeves returns to the bog screen Friday in the thriller “John Wick.” Also, “The Theory of Everything,” a biographical movie about physicist Stephen Hawking, premieres this week. Suzanne Marques reports on the day’s top entertainment news. Source

The president said he loves voting, but will he say who got his vote? Source

The People’s Protection Units, a Syrian-Kurdish fighting force also known as YPG,has been fighting against ISIS sine the terror group began its land grab. Despite being outnumbered, outgunned and surrounded by enemies, YPG continues to battle ISIS with whatever it can. Stuart Ramsay of CBS News partner Sky News reports from Sari Kani, Syria. Source

There’s a new smartphone app that allows medical marijuana users to get delivery from dispensaries to their door. The app, Nestdrop, is a medical delivery service created by founders Roddy Rodnia and Michael Pycher. KCBS reports. Source

A woman caught in the crossfire between protesters and football fans had to be treated for a black eye after about 20 demonstrators rallying for Mike Brown clashed with Rams fans outside of the Edward Jones Dome. The police department in St. Louis say two people were arrested. KMOV reports. Source

Liberian natives who have healthcare jobs in the U.S. are being urged to consider traveling to the area where Ebola is at its worst — West Africa. A congressman explained the need for help to quell the spread of the virus. WCCO has the story. Source

Groom Matt Ficarra stole the spotlight at his wedding. The 30-year-old was paralyzed from the waist down in a boating accident more than three years ago, but was able to walk his bride down the aisle using a exoskeleton. Norah O’Donnell reports. Source

The Chinese drank 11 billion liters of Baijiu last year, making it the most consumed spirit by volume. After suffering a significant loss in revenue, Sichuan Swellfun CEO Jim Rice is hoping a new approach will reinvigorate the business. Seth Doane reports. Source