Antidepressants Only Benefit Certain Depressed Patients

ScienceDaily (Feb. 27, 2008) — A new study suggests that antidepressants only benefit some, very severely depressed patients. "New generation" antidepressants, such as fluoxetine (Prozac) are widely prescribed for the treatment of clinical depression. However some studies have suggested that these drugs do not help the majority of depressed people get better by very much. Irving Kirsch, from the University of Hull, and his colleagues, studied this question in closer detail, looking at whether a patient's response to antidepressant therapy depends on how badly depressed they are to start out with.

Kirsch and colleagues used a technique called "meta-analysis", where they put together data on clinical benefit from all the trials submitted to the US Food and Drug Administration for four drugs: fluoxetine (Prozac), venlafaxine (Effexor), nefazodone (Serzone), and paroxetine (Seroxat / Paxil). (The researchers also wanted to include sertraline and citalopram, but couldn't find all the relevant data for those two drugs).

By including data from unpublished as well as published trials, the researchers set out to avoid bias that might come from non-publication of disappointing findings.

When the data from all of these trials had been put together, the improvement in depression amongst patients receiving the trial drug, as compared to those receiving placebo (dummy tablets), was not clinically significant in mildly depressed patients or even in most patients who suffer from very severe depression. The benefit only seemed to be clinically meaningful for a small group of patients who were the most extremely depressed to start out with. This improvement seemed to come about because these patients did not respond as well as less depressed patients to placebo, rather than responding better to the drug.

Irving Kirsch, summarising the paper,* says: "Although patients get better when they take antidepressants, they also get better when they take a placebo, and the difference in improvement is not very great. This means that depressed people can improve without chemical treatments."

Given these results, the researchers conclude that there is little reason to prescribe new-generation antidepressant medications to any but the most severely depressed patients unless alternative treatments have been ineffective.

TUESDAY, Feb. 26 (HealthDay News) -- While popular antidepressants such as Prozac are widely prescribed for people with varying degrees of depression, the drugs are only effective for those with the most severe depression, a new study suggests.

"Although patients get better when they take antidepressants, they also get better when they take a placebo, and the difference in improvement is not very great," lead researcher Irving Kirsch, a professor of psychology at the University of Hull in Great Britain, said in a prepared statement. "This means that depressed people can improve without chemical treatments," he added.

In the study, Kirsch and his colleagues collected data on 35 clinical trials of drugs called selective serotonin reuptake inhibitors, or SSRIs, whose results had been submitted to the U.S. Food and Drug Administration. The antidepressants included in the trials were fluoxetine (Prozac), venlafaxine (Effexor), nefazodone (Serzone), and paroxetine (Seroxat/Paxil).

An analysis of the data showed that patients taking antidepressants fared no better than patients receiving a placebo. This appeared to be the case whether the patients were mildly or moderately depressed.

The drugs only seemed to benefit a small group of patients -- those with the severest depression when the study began.

Based on these results, there appears to be little reason to prescribe these antidepressants to anyone but the most severely depressed patients, the study authors concluded.

Dr. Nada Stotland, president-elect of the American Psychiatric Association, said she wasn't surprised that the study found that not every antidepressant works for every patient. Many people who are depressed don't respond to the first antidepressant they try. It can take up to an average of three different antidepressants until one works for a particular patient, she said.

"Medication helps some, but not all, people with depression," Stotland said in a prepared statement. "For people with mild to moderate depression, psychotherapy can work as well as medication. Studies have shown that between 70 and 80 percent of people can and do get better with a combination of treatment approaches, which will often include individual therapy, family therapy and/or medication.

"Therefore, testing any single antidepressant on a group of depressed individuals will show that many of them do not improve," Stotland added. "There is a small group of depressed individuals who do not respond to any antidepressant."

The new study highlights the fact that treatment for depression needs to be tailored to an individual, and that the most effective treatment will often include multiple approaches, Stotland said. The study results also suggest that more long-term follow-up trials are needed to determine which patients are most likely to benefit from specific therapies.

"Some of the most exciting research in progress at the present time concerns our attempt to match the antidepressant to the patient from the outset; we may be able to perform laboratory tests or identify clinical factors that let us know in advance which antidepressant will work for each person," Stotland said. "That will be an enormous advance for the millions of people suffering from this very painful and potentially disabling disease."

SOURCES: American Psychiatric Association, news release, Feb. 26, 2008; PLoS Medicine, Feb. 25, 2008, online