Imaginary friends - should I be worried?

[satine]

My ds (3.5) talks a lot about his imaginary friend, down to such details as where he lives and how old he is. It comes up more and more now. Now I know I shouldn't be basing my parenting on what I see in US comedy shows but last night on Desparate Housewives, Lynette was told that her son's imaginary friend might have appeared as a coping mechanism or reaction to some upsetting event. Help! Is my poor son reacting to his dad being away for 6 months (although he's been back for 2 months now) or the fact that I shout too much?

Just to add to the list so's to show how common and un-pathological this is, my ds (7) and dd (5.5) have a whole host of shared imaginary alter egos/friends in the form of an ever-increasing family of amphibious whales. Bella, Draffir and LittleB are the ones we see and hear most of.

In our case (and I'd imagine this is a pretty common root cause) it has a lot to do with how much they would like a little sister - hence the pod's high birth rate.

Oh, and Pew. How could I have forgotten Pew? He was the original.

And Sunbaby, their god.

Shades of Gondal there I think bink!
Randall was fecund too. We have one of those hilarious blob on long legs toddler drawings of him with his "eight babies" on the wall. Hey, I know my bump with dd was large, but...

ooh my bex had an imaginary friend called verrican who apparantely was native indian and lived in our garden in an imaginary wigwam.She is 9 now and doesnt remember verrican at all.

My dd had Max, he was older than her and he often did naughty stuff (farting etc !). He was with us most of the time and dd said he looked after her and that he was 'one of the family', she sometimes referred to him as 'my brother'. There was nothing I could think of that was troubling dd to need this imaginary friend.
But I had lost a baby boy at five months before having dd !!!!!!! And Max had been high on my names list.