If you have done anything that is quite significant and can contribute to your course then yeah definetly include why you chose to do a gap year. Make sure you make your personal statement as personal to you as possible and don't just say things I done this and gained communication skills or whatever. Make every word as meaningful as you can.
For the intro maybe start with a personal experience for example I was born in Poland and then I moved here when I was 7. You could talk about how the economy has changed. Or you could bring in the middle eastern crisis, brexit and the two idiots trump and clinton. I realise what I said is very brief but I can't write it for you as you need to make it your own.
I wish you the best of luck with your personal statement and your offers!