Walking through downtowns across the United States, one could be excused for becoming numb to outbursts from visibly disturbed and impaired individuals. Two decades ago, the idea that major American cities would condone (or in some cases, encourage) this situation was unthinkable. If a person was unable to take care of themselves, the options were moving to shelter or, if illness put themselves or others at risk, a clinical setting. Tent-filled homeless camps that stretch across city blocks or throughout public parks were simply not on the table.

A recent UCLA study confirmed the obvious: More than 75 percent of the unsheltered homeless surveyed have a substantial mental health problem, 75 percent have an alcohol or drug addiction, and the majority suffer from both. These afflictions, not a lack of housing, drive street homelessness in America.