When it comes to the acne drug Accutane, ignore the label and the news media hype and look at the science, a South Hills dermatologist testified yesterday.

Research reveals an overwhelmingly safe "miracle drug," Mark Seraly said, that has helped more than 14 million patients.

"There is so much myth and misperception attached to this medication that is clearly not based on what we've observed over 27 years," Dr. Seraly said.

The controversial drug is at the heart of the defense for John Mullarkey, a 20-year-old Monroeville man who stabbed his on-and-off girlfriend to death Aug. 15, 2007, and tried to take his own life. Mr. Mullarkey's attorney, Robert E. Stewart, is arguing that his client was unable to form the intent to kill 16-year-old Demi Cuccia -- a crucial component of first-degree murder -- because of depression caused, in part, by Accutane.

Testimony concluded yesterday with prosecution rebuttal witnesses, including Dr. Seraly, and closing arguments are scheduled for Monday before Common Pleas Judge Jeffrey A. Manning.

The case is believed to be the first Accutane defense for a homicide, but the drug has been blamed for scores of suicides and incidences of depression.

Those reports are scattered and unscientific, said Dr. Seraly, who operates a private practice in Peters. He quoted research that Accutane patients commit suicide at one fourth the rate of their age group, and he said that in the 3,000 Accutane patients he's treated over 15 years, there is generally an improvement in self-esteem as the acne clears up.

"So maybe we ought to be putting more people on Accutane," Dr. Seraly said.

During cross-examination, Mr. Stewart brought up FDA-mandated warnings of depression or suicide, which Dr. Seraly claimed were prompted by unscientific reporting methods and were a symptom of over-caution and fear of litigation.

Mr. Stewart also suggested Dr. Seraly was biased toward the drug because he has given lectures at pharmaceutical company-sponsored events, and it would be bad for his business if he did not speak highly of the drug.

Mr. Mullarkey began his Accutane treatment in April 2007 at Allegheny Dermatology Associates in Monroeville, where he was seen by physician's assistant Dayna Turrill, who testified yesterday.

Ms. Turrill testified that Mr. Mullarkey never reported depression or any other psychological side effects, and after initial problems with headaches, Mr. Mullarkey's dosage was cut in half and he seemed fine.

By June, reports note he was "clear and happy," as the medicine successfully treated his persistent acne.

Deputy District Attorney Mark V. Tranquilli also called Bruce Wright, a psychiatrist who examined Mr. Mullarkey. Dr. Wright mostly agreed with the diagnosis of defense psychiatrist Dr. Robert Wettstein that Mr. Mullarkey had an adjustment disorder with a depressed mood, related to his tumultuous relationship with Demi, a Gateway High School cheerleader.

But Dr. Wright had one key difference. He found no evidence of cognitive impairment in Mr. Mullarkey around the time of the stabbing, a view he reinforced with the fact that Mr. Mullarkey was able to text message his mother and communicate with paramedics immediately afterwards.

"He was able to plan and premeditate his behavior," Dr. Wright said. "He was able to carry out planned activities."

As for Mr. Mullarkey's claim of not remembering the stabbing, Dr. Wright said, "It's not out of the realm of possibility, but it is convenient."