The 32-year-old actress plays geeky guidance counsellor Emma Pillsbury - who has mysophobia, an obsessive fear of germs and contamination - and admitted she is similar to her alter-ego in the TV series because she has the same kind of OCD experiences as her character.
She added: "Emma famously suffers from OCD and I suppose I do have a bit of that. The other day, I noticed I'd arranged my spices in alphabetical order when I was on the phone, without even realising, and when I was a kid I was constantly cleaning and organising things - my toys, my sister's cosmetics."
Jayma - who married English actor Adam Campbell in 2007 - also revealed she found it hard to "have fun" when she was younger because she was always thinking about where her next job would be.
In an interview with Stylist magazine, she said: "I was so focused at 21, maybe to my own detriment because I didn't allow myself to have fun. I was constantly looking for the next audition and working to pay the bills.
"I would tell myself to relax a little more and have fun. I feel really content in my 30s actually - I don't feel like the wisest person in the world but I definitely don't worry or stress like I used to."