Pharmaceutical companies spend a lot of time and money trying to convince doctors and patients that their brand-name drugs are better than the products sold by their competitors.
But when it comes to antidepressant medications, one drug is much like another in terms of its ability to lift patients out of the blues, according to the results of a major review study of previously conducted trials.
"They are pretty much the same, despite what the companies say," lead researcher Gerald Gartlehner of the Danube University in Austria said in an interview.
The researchers reviewed 234 studies to compare the most widely prescribed antidepressants, such as SSRIs (selective serotonin reuptake inhibitors), SNRIs (serotonin and norepinephrine reuptake inhibitors) and other medications that target neurotransmitters in the brain.
The findings, published in the Annals of Internal Medicine, showed no important differences in effectiveness among the medications.
However, that doesn't mean all the drugs are identical, noted Dr. Gartlehner. They may vary in how quickly they take effect, their dosing schedule, price and – most importantly – their side effects. It's these differences that can make a particular antidepressant the drug of choice for certain patients.
Some patients experience, nausea, restlessness, weight gain, decreased sex drive and other adverse effects while taking an antidepressant. And some drugs are more likely to trigger specific side effects.
But "it's not possible to predict who will have what side effect on a particular drug," said Dr. Gartlehner. Furthermore, up to 40 per cent of people won't respond to a medication. In other words, they don't feel any better. So, patients must try various medications to determine what's suitable for them. If there is no obvious benefit after a month, or the side effects are hard to tolerate, a patient should be switched to another medication, said Dr. Gartlehner. "It really is just trial and error."
Some unfortunate patients are resistant to all current drug treatments.
"The main message from our study is that the drugs are very similar and there is no reason to chose one over the others just based on effectiveness," he said. Much depends on the response of the individual patient.