SIBUTRAMINE witch is also Serotonin inhibitor is used in obesity treatment (used for weight loss)
And why SIBUTRAMINE is not classified as antidepressant although in increases the serotonin level between neurons?!!

The drug makes you feel full - acts as an appetite suppressant. The drug is not supposed to be taken by depressed people, manic people or those with eating disorders due to effects on serotonin which could result in unpredictable mental behavior.
The newer SSRI's do not have weight gain issues. I lost 60 lbs while on an SSRI. SSRI's do not suppress appetite as the body retains water and fat.