There are more than 9,000 homeless people on the streets in Washington, D.C. and most of them have their own sets of problems and challenges. And while most of these difficulties were contributing factors to their homelessness, one common problem is both a catalyst and a result of life on the street: mental illness.

In D.C. alone, 15% of the homeless people in the continuum of care –which only includes those that have sought out care -- are “severely mentally ill,” according to the Community Partnership for the Prevention of Homelessness. These psychiatric illnesses include schizophrenia, bipolar disorder, major depression, post-traumatic stress syndrome, and obsessive-compulsive disorder, all of which can cause significant disability.

Nationally, U.S. Department of Health and Human Services has reported that 40% of people nationwide who experience chronic homelessness have substance-abuse disorders, 25% have some form of physical disability or disabling health condition, and 20% suffer from serious mental illness. In July of 2005, the National Coalition for the Homeless found that 20% to 25% of the single adult homeless population suffers from some form of severe and persistent mental illness.

Mental disorders are a strong predictor of homelessness because they prevent individuals from carrying out the essential tasks of daily life, according to mental health experts. As the National Coalition noted, mental illness can cause people to neglect self-care, everyday household responsibilities, and relationships. This diminished capacity to cope with life’s responsibilities can create a slippery slope that can end to life on the street.

“[Homeless people] start developing symptoms of the mental illness … then they cannot get to work on time, they make mistakes, they cannot concentrate, they get in fights,” said Dr. Robert Keisling, associate medical director of mental health at Unity Health Care Inc., an organization that provides healthcare to D.C. residents whether or not they are able to pay for treatment. “Because of their mood instability, they lose their jobs … then they cannot pay the bills, [and] this precipitates to homelessness.”

Whether someone with a mental illness follows the slippery slope to homelessness depends on factors such as the severity of the illness, the individual’s awareness of the problem, and the additive effects of other medical problems, according to Keisling.

“Most of the patients I see have a pre-existing mental illness, substance abuse or both,” he said. “Some condition exists that contributes them to becoming homeless.”

Sasoura Movazeji, director of social services for Unity Healthcare, agreed. “In most of the cases, the person already has an underlying mental illness,” said Movazeji. “In 75% of the cases there is a co-occurring disease or disorder…symptoms are [often] exacerbated after the person becomes homeless.”

Many homeless people who struggle with mental illness experienced a life-altering break that precipitated their loss of housing. These life-altering events are stressors that can both induce mental illness and complicate its management. Researchers Dr. Kathleen Brady and Dr. Rajita Sinha observed in American Journal of Psychiatry that “one of the bridging constructs between psychiatric and substance-use disorders is the role of stress in the development and relapse of … disorders.”

Patty Smith, a 52-year-old woman who has experienced homelessness and mental illness, explained her turning point: “[I suffered] depression over the loss of the person who raised me … I did not know how to cope with that loss and loss of her income.” Only after becoming homeless was Smith was diagnosed with bipolar disorder.

The experience of Maurice King, a formerly homeless D.C. resident, is similar. King once held various prominent jobs as a technical writer and contractor. He supported his family financially and helped care for his autistic son. However, King was forced to take a major pay cut and then experienced severe marital problems that involved systematic emotional abuse and physical violence. These eventually led to divorce. After the divorce and his subsequent loss of custody of his son, King’s downward spiral into depression ended with him living on the streets.

The nature of life on the street often only worsens the stress-related problems homeless people face, said Keisling. “Being homeless is a stressful situation,” he noted. “People have stuff stolen from them, they get robbed, beat up, and raped. [This] does not make the situation any better; it compounds the difficulty of getting treatment and obtaining medications.”

But there have been recent efforts to try and provide more than just the rudimentary treatment to homeless people suffering mental illness.

In the academic community, research continues about the mental illness-homelessness connection. In the article “Housing First, Consumer Choice, and Harm Reduction for Homeless Individuals with a Dual Diagnosis,” Drs. Sam Tsemberis, Leyla Gulcur and Maria Nakae discuss strategies for housing homeless people with mental illnesses and substance-abuse disorders. Their research suggests that it is better for service providers to provide housing and then address a person’s psychiatric struggles, rather than offer housing contingent upon an individual’s committed participation in a treatment program and adherence to strict rules.

Some cities are also addressing the link between mental illness and homelessness, establishing “assertive community treatment teams,” initiatives that employ case managers to do home visits with formerly homeless people who grapple with mental illness. The case managers check to be sure their clients have medication and food and are paying rent. However, there are large gaps nationwide between the supply of such care and demand in the homeless population.

King, who is getting treatment but is still homeless, said that his experience navigating services offered for homeless people with mental illness in D.C. involved many hoops and few direct paths. But despite his long struggle, his message is a hopeful one for the thousands of homeless people in D.C. that grapple with similar problems, “Treatment is out there,” he says.