Around 20 milligrams of Prozac, two-to-four weeks worth of time and a little patience. Psychiatrist Peter D. Kramer sees nothing wrong with this prescription. Nor should anyone else fighting depression, he says.

Mr. Kramer discussed his new book Ordinarily Well: The Case for Antidepressants at the West Tisbury Library on Friday evening. He defended the effectiveness of antidepressants using a clinical perspective and industry-sponsored research.

Mr. Kramer studied psychiatry at Harvard Medical School, and he visited Martha’s Vineyard for the first time while studying rural agriculture during the 1970s. Currently a professor at Brown University, Mr. Kramer wrote the New York Times bestseller Listening to Prozac and frequently speaks at the West Tisbury library.

The psychiatrist uses quality of life as one standard to measure antidepressant effectiveness. Whether or not a person performs well at work, raises their kids effectively or simply enjoys life more, determines an enhanced quality of life, he said. Describing his book as highly integrated, Mr. Kramer focuses on debunking the placebo argument, which claims that those who take antidepressants convince themselves the pills work without any biological effect actually occurring. Mr. Kramer said part of the proof was in the changes the brain underwent due to the pills.

“It’s not just one distortion,” Mr. Kramer explained. “You see one distortion and another distortion. After a certain point I hope the reader thinks it doesn’t seem like the placebo plays a certain role in what these drugs are doing at all.”

Placebo pills are used during controlled drug experiments where scientists replace a drug’s active ingredient without the patient knowing it to test for any underlining psychological influences.

Mr. Kramer used the treatment of Parkinson’s disease as an example. A person might feel better using placebo pills during a test trial. However, when given typical drugs for Parkinson’s disease, scientists can clinically assess whether a patient’s brain and body are responding favorably.

“So even if there is some placebo effect that is operating in people who do well in the placebo rounds of drug trials, that doesn’t mean that a percentage of what goes on in people on medication is due to the placebo effect,” he said.

Mr. Kramer believes a popular stigma surrounding depression contributes to the resistance against using antidepressants. Some view depression as a disease people simply “get over.” However, much like any other disease, depression has debilitating mental and physical effects that require medical treatment.

“It’s not something that you’re going to get over by just wishing,” he said. “These medicines work just as well as other things in medicine.”