Happy Pills Makes me....happy? Non-stop laughter??

Ok so I've recently been prescribed anti-depressants, specifically sertraline, and when they come into effect I essentially cannot stop smiling and laughing, even whilst being told off. Now usually, I rarely laugh and smile as a personified rock mixed with a black cat type of gal,

but is this side affect normal ???

The only other symptoms would probably be nausea and dizziness, that's it...