Celebrex is an anti-inflammtory. Do you mean Celexa? That's the anti depressant Sid takes.
As you are probably are sick of hearing us say - Everyone is different. They have a tendency to cause sleepiness, so Sid takes his at night. I also take mine (Zoloft)at night, because they made me so tired when I took them in the morning. Try it in the morning, and if he seems too sleepy, try it at night.