I went through a host of side effects on taking Citalopram which died down after about 2 months.
Be aware that Citalopram is a mild antihistamine and so can cause drowsiness in some patients. It is recommended that if it acts as a sedative that the dose may be taken at bedtime rather than in the morning.
Here's a list of side effects, many of which I suffered, particularly nausea which caused weightloss as I didn't want to eat. Also clenching my jaw to the extent of getting face ache. I yawned ALOT and had vivid dreams and extreme fatigue.
Common side effects of citalopram include drowsiness, insomnia, nausea, weight changes, vivid dreaming, frequent urination, decreased sex drive, anorgasmia, dry mouth, increased sweating, trembling, diarrhea, excessive yawning, and fatigue.
Less common side effects include bruxism, vomiting, cardiac arrhythmia, blood pressure changes, dilated pupils, anxiety, mood swings, headache, and dizziness. Rare side effects include convulsions, hallucinations, and severe allergic reactions.
There are new studies which consider Citalopram ineffective for mild depression, shown by placebo trials. Severe depression is well suited to the drug however.
It's a mildly traumatic induction period taking Citalopram, but I did find it helped. However I became slow, disinterested without worry, unexcited by anything, content to let the world go by. After 4 years I am now 3 stone heavier. The contentment with life is now juxtaposed with depression with my weight! So I'm dropping from 20mg to 10mg and working my way through the haze to do more exercise.
Good luck !