Similarly, a study of heroin addicts in Baltimore published in 1997 found that while 39 percent had a psychiatric disorder, only 5 percent suffered from a "serious" illness such as psychosis, bipolar disorder or major depression, said Hopkins psychiatrist Dr. Van L. King, a co-author.

Since 2004, BBH clinicians have deemed nine out of 10 patients who arrived in the grip of drug addiction as having a separate mental health problem, according to the state Alcohol and Drug Abuse Administration. And the center has historically put most patients into treatment regimens designed for the severely mentally ill — those on the verge of needing inpatient therapy in a psychiatric ward.

BBH says it has a large overlap because its specialty is treating those with both mental illness and an addiction. Hathaway likened it to a pulmonologist with many asthma patients. "Most patients," he said, "are referred to us from other agencies with a psychiatric diagnosis."

But BBH submits annual reports to the state showing that up to two-thirds of its drug-addicted Medicaid patients walk in without a referral. A social worker who worked at BBH until last year estimated that half of the company's patients came in off the street.

With so many walk-ins, far fewer than 90percent of BBH patients would likely suffer from both mental illness and addiction, let alone need intensive psychiatric treatment, veteran practitioners say.

Dr. Michael Fingerhood, 50, an associate professor and addiction specialist at the Johns Hopkins University School of Medicine, says more than a hundred BBH patients have come under his care. Most told him they were assessed as bipolar by BBH staff, he said, but he estimates that just 10percent fit that diagnosis.

"The majority of them have adjustment disorder or personality disorders that are related to their drug use," he said of BBH patients he has treated for detoxification at the Hopkins Bayview Medical Center. With sustained sobriety, Fingerhood said, signs of the disorder often fade away. Though not a psychiatrist, he has more than two decades of clinical experience.

"Do I think BBH helps people? Yes," he said. "But I think … they're doing a disservice to people by labeling them as bipolar."

Even in the best clinical scenario, a psychiatric diagnosis is tricky, experts say; doctors have no X-rays to help apply the criteria defining a mental illness. Welsh said it's particularly hard in abusers of heroin, the drug most commonly used by BBH patients. "Because the withdrawal from heroin is so miserable," he said, "people can feel miserable for weeks or more as they're still detoxing."

Rather than withholding a mental health diagnosis and starting with drug treatment, BBH says it often puts patients on psychiatric medication straightaway. That, Welsh and others say, makes it hard to tell whether sobriety and drug counseling would have brought improvement.

Welsh said he believes many patients benefit from BBH. But "I know patients that go to BBH that I'm absolutely convinced do not have a mental illness."

Getting into BBH

They go to BBH for different reasons. Some patients clearly need help with interconnected drug addiction and psychiatric problems, such as schizophrenia or bipolar disorder, former patients and staff members say. Some are referred from hospital inpatient units.

BBH "saved my life," said Chris Schussler, 53, who says he was treated for mental illness last year at Sheppard Pratt before going to BBH for further treatment.

Bon Secours Hospital in West Baltimore refers some patients from its inpatient psychiatric unit, said Dr. Darryl M. Coleman, a psychiatrist there. "The majority of what I've heard [about BBH] is good," he said. "Of course, you hear some complaints about everywhere."

Other former patients told The Sun they simply wanted treatment for drug addiction and went along with a psychiatric diagnosis that they doubted because it seemingly was the price of admission.

Still others are drawn by the prospect of housing. BBH, though outpatient only, offered free beds for years before it began charging patients $150 to $200 a month.

For most patients, the road to BBH has usually started in Baltimore, sometimes after a suggestion from a friend, relative or fellow junkie. Some have gone straight from a city jail cell.

James Scriven, 44, was about to get out of jail in 2004 after a drug conviction when he heard of the program from a cellmate.

"He said, 'You can go to BBH, but you have to tell them you're dual diagnosis,'" Scriven recalled. "I said, 'Dual diagnosis?' [He said], 'You have to tell them you have a mental problem and a drug addiction. You tell them you're depressed, they'll put you on public assistance and they'll put you right in.' That's what happened."