The life of a psychiatrist can be unpredictable simply because he works with patients who may be mentally unstable.

But Dr. Thomas Cobb’s new position is a bit less stressful than his previous job. In August, he joined the staff at Laurelwood, Northeast Georgia Medical Center’s inpatient treatment facility for mental health and substance abuse problems.

Prior to that, Cobb, 36, was director of forensic psychiatry at the Medical University of South Carolina in Charleston. One of the challenges of that job was explaining what he did for a living. When people heard the word "forensic," they usually thought of the "CSI" TV shows, which depict murder investigations.

But Cobb said forensic simply refers to anything related to the legal system, and forensic psychiatry is "where psychiatry and the law cross."

"Anytime you have a patient who has a psychiatric illness and happens to be anywhere in the legal system, and their mental illness may be impacting their decision-making ability or may have some control over their culpability, that’s when a forensic psychiatrist is called in to do an evaluation and render a professional opinion," he said.

The classic example of that is when a defendant’s lawyer seeks a plea of "not guilty by reason of insanity." Cobb said any psychiatrist can testify in court. But those who have been trained in forensic psychiatry "know the ins and outs of the legal system and what the statutes are."

"The legal definition of a mental illness can be very different from the psychiatric definition," he said.

The conventional wisdom is that many criminals claim insanity just so they can escape the death penalty. But Cobb said the insanity defense is actually relatively rare. And deciding on a person’s mental status is not something he takes lightly.

"A typical forensic evaluation includes an initial interview that lasts three to four hours," he said. "Then you go through stacks of records, and sometimes you conduct psychological tests and do further interviews, including with family members and with (medical) people who treated the person. It’s a process that can sometimes take months."

A common assumption is that anyone who commits a heinous, gruesome murder is by definition insane, because no normal person would do such a thing. But Cobb said that’s not necessarily true.

"Some people are sociopathic, which is a personality type, not a psychiatric disorder," he said. "On the other hand, you do have some people who are psychotic, who hear voices telling them to do things."

A recent, well-publicized case illustrates the difference. When Gary Michael Hilton was charged with the death of hiker Meredith Emerson in Northeast Georgia last month, there was speculation that his attorney would seek the insanity defense. Reports of Hilton’s odd behavior on hiking trails seemed to lend credence to the assumption that he was mentally ill.

But on Jan. 31, Hilton pleaded guilty to the murder, without claiming insanity. He reportedly told investigators that he kidnapped Emerson just so he could use her ATM card. After three days of unsuccessfully trying to withdraw money, Hilton killed Emerson, apparently to prevent her from talking to police.

Hilton agreed to admit his guilt in exchange for not receiving the death penalty. But when Cobb spent three years working in the South Carolina prison system, he counseled many people who did end up on death row.

"It helped me sharpen my skills, because you’re dealing with the extremes of mental illness and behavior," he said.

Although the prisoners were not judged legally insane at the time they committed their crimes, Cobb said many later developed mental disorders while they were in prison.

"A lot of people don’t know that the criminal-justice system is the largest mental-health provider in the country," he said.

Working on death row was often surreal, Cobb said. "That system is a world unto itself, the way it functions," he said. "I had to keep an open mind and reserve judgment. It certainly humbles you and makes you grateful for what you have. I had two patients executed during my time there. Fortunately, neither one asked me to be present during the execution."

In addition to seeing patients on death row, Cobb also had to visit maximum-security facilities. "These (prisoners) were the worst of the worst, with no impulse control," he said.

Yet he never felt concerned for his own safety within a prison setting. "I’ve felt more afraid doing general psychiatry, working with people who’ve just come in off the street and you don’t know anything about them." he said. "In the ER, you don’t have security (guards) right there."

Cobb said many psychiatrists find forensic work distasteful and don’t want any part of it. "My position was, If I don’t do it, who will?"

A South Carolina native, Cobb always had a desire to help people and majored in psychology as an undergraduate.

"I went to medical school specifically to become a psychiatrist," he said. "I felt it would put more tools in my bag to handle things."

Because they are physicians, psychiatrists can prescribe drugs or other medical treatments if necessary. Psychologists cannot, and must refer patients to a doctor if medication is indicated.

But Cobb tries to dispel the image of psychiatrists as being too willing to resort to drug therapy.

"I’m conservative. I don’t reach for the prescription pad as soon as a patient walks in the door," he said. "I actually spend a lot of time taking people off medications (that other doctors have prescribed)."

But in some patients, psychiatric illness is believed to be caused by an imbalance in brain chemicals, and "talk therapy" doesn’t work unless it’s combined with medication that allows the patient to function.

At Laurelwood, Cobb takes a special interest in treating depression, bipolar illness, and anxiety disorders, all of which tend to respond well to a combination of medication and counseling.

When Cobb decided to leave his position in South Carolina, he looked toward Georgia, where both he and his wife had relatives. They now live in Suwanee.

"I’ve got two small kids, and the schedule of doing forensics full-time as well as teaching was very unpredictable," he said. "It clashed with what I wanted for my growing family."

Cobb said he had been close to signing on with a psychiatric hospital in Atlanta when, "on a lark," he answered a recruiting ad for Laurelwood. And he’s glad he did.

"I have been incredibly happy since I came here," he said. "I see a diverse range of patients, and the staff is great."