An international analysis found that antidepressants can help sustain improvement in depression beyond the short term, though the medicines differed in their longer-term effectiveness and acceptability.

The review pooled 115 studies involving more than 30,000 people and compared 21 medications, using fluoxetine (Prozac) as the benchmark because it was the first widely used SSRI.

Researchers assessed short-term outcomes after four to eight weeks against longer-term results after six to 12 months; the studies overall lasted from 12 weeks to two years.

Escitalopram (Lexapro) and duloxetine (Cymbalta) provided more enduring relief than fluoxetine, with escitalopram ranking highest among SSRIs and for preventing relapse, followed by agomelatine and duloxetine.

Co-researcher Eric Ruhé said the comparison with fluoxetine amounted to one additional person improving for every eight treated with escitalopram.

Patients taking escitalopram or duloxetine were also less likely to stop treatment than those taking fluoxetine, while discontinuation was especially common with reboxetine and milnacipran, and higher with bupropion in a supplementary analysis.

Bupropion and reboxetine showed weaker sustained results than many of the other medicines, while the researchers said more evidence is needed to draw firm conclusions about several drugs.

Clomipramine appeared to perform best in one comparison, but that finding rested on a single trial with just 32 participants and was too uncertain for firm conclusions.

The differences between medicines were modest, and the findings cannot tell which antidepressant will work best for a particular person or justify switching a treatment that is working well.

The researchers said the results may help inform future guidelines and support shared decisions, but medication choice should be tailored to each person’s circumstances and preferences.

That decision involves weighing likely benefits against side effects such as weight gain, fatigue, sleep changes and sexual dysfunction, as well as considering past responses and a patient’s confidence in a medication.

Agomelatine is not approved in the United States and carries a rare risk of liver injury, making it potentially unsuitable for people with liver problems or an elevated risk of liver failure.