LONDON, Feb. 23 (Xinhua) -- Anti-depressants do help lift people's mood, although their effects vary, according to a recent study published in the London-based medical journal The Lancet.
The study, which analyzed data from 522 trials involving 21 common anti-depressants, found that all tested drugs were effective in treating depression.
Drugs were deemed effective if symptoms were reduced in at least half of patients over two months.
Lead author Dr. Andrea Cipriani said he was "very excited" about the findings, which he said provided a "final answer" to the controversy over the effectiveness of the drugs.
The study also gives a comparison of the 21 types of anti-depressants.
It says that agomelatine, amitriptyline, escitalopram, mirtazapine and paroxetine were the most effective anti-depressants among the ones that were tested. Meanwhile, the well-known brand Prozac, or fluoxetine, was one of the least effective ones.
Led by Oxford University, the study hopes to settle doubts and debates over anti-depressants, which has been described by some people as conspiracies of big firms or no more effective than placebos.