Different antidepressants have major divergences in their side effects on the physical health of a patient.
As reported by the BBC, academics ranked the medications for the first time after observing the impact of the drugs in the first eight weeks after starting treatment.
Around eight million people in the UK take antidepressants.
Researchers warned that the wide disparity in side effects could affect people's health and could also determine if they should stick to their prescription.
Prof Oliver Howes said, "There are big differences between [antidepressants] and this is important not just for individual patients, but large numbers of people are taking them, so even modest changes could have a big effect across the whole population."
The study by King's College London and the University of Oxford is the first to create a ranking so the effects of medication can be easily compared.
The team analysed 151 studies of 30 drugs commonly used in depression, involving over 58,500 patients.
Not everybody developed side effects; however, results published in the Lancet medical journal showed that on average:
1. An eight-week prescription of agomelatine was linked to a 2.4 kg drop in weight compared with maprotiline, which caused nearly 2 kg of weight gain.
2. There was a stark difference of 21 beats per minute between fluvoxamine, which slowed the heart, and nortriptyline, which sped it up.
3. An 11 mm Hg difference in blood pressure between nortriptyline and doxepin was also observed.
"Clearly no two antidepressants are built the same," said Dr Atheeshaan Arumuham, from King's College London.
Those differences can stack up in ways that become clinically important, including an increased risk of heart attack or stroke.
