AP PHOTOS: Poverty and addiction grip Los Angeles' Skid Row

The Skid Row area of downtown Los Angeles is home to thousands of chronically homeless people.

Each one has a different story about how they ended up in this center of abject poverty, where drugs rule the streets night and day.

"It's miserable quitting, or trying — trying anything," 33-year-old Andrew Hudson said recently while using heroin on Skid Row.

America's homeless population increased this year for the first time since 2010, driven by a surge in the number of people living on the streets in Los Angeles and other West Coast cities.

According to the latest nationwide count, four of every 10 people who are homeless in the U.S. have a serious drug addiction or are severely mentally ill.