Why did you choose to write about this topic?

I jumped at the opportunity to write about human rights issues concerning lesbian, gay, bisexual and transgender (LGBT) people. It doesn't really matter that I'm gay myself, everybody should stand up for equality. Any sort of unfairness has always sickened me and I genuinely can't understand why some people, organisations and places hate LGBT people so much. No one chooses to be gay and no one chooses where they were born, and yet in over 50 countries around the world it is illegal to have same-sex sex. In some, gay people face the death penalty simply for loving someone the same gender as them. This is clearly unacceptable. I feel very fortunate I was born in the UK but also guilty because I sometimes take for granted the freedom to love who I want. Had I been born in Saudi Arabia or somewhere with similar laws, I could have been executed by now.

Did you find writing from the perspective of a teenager, particularly a female challenging?

I think I have a bit of a Peter Pan complex! Inside I feel about 15 – which, coincidentally, is the age I came out – so writing teenagers comes quite easily. I think the trick is not seeing young adults as "kids". I would never assume that young people have less intelligence or experience than I do. I hear the gender thing a lot. Given that I write thrillers, I think guys and girls would react in pretty much the same way – fight or flight. I also believe guys and girls are all unique regardless of their gender so it's just about painting that individual. Maybe being gay allows me to understand how a girl would feel towards a hot guy, but I like to think I could write straight male characters just as convincingly.

I liked your subtle approach when adding in homosexual characters, what made you decide to write them this way?

I just wanted to see a few more characters like me and my friends. When I was a teenager I never read about people like me and that sucked. As soon as I set out to write Hollow Pike I wanted to make Kitty, Jack and Delilah queer – I wouldn't say "homosexual" because I think they're still figuring it out. In Cruel Summer, Ryan is a little older and has come out as a gay man.

What are your thoughts on the new legislation sitting in front of the government regarding gay marriage?

It's gone through! It's so great. All any of us want is equality, right? It sometimes feels like LGBT people are the last group in the country that can be openly discriminated against (actually along with the poor) so marriage equality is a big step forward. My only grumble is what took them so long. To me this one was a no-brainer.

You dedicated Hollow Pike to "everybody who has ever hated school"? What made you decide to write about the issue of bullying in schools?

I hated school so SO much, but leaving was never an option. I needed to do well to make my escape! I wrote Hollow Pike for all the young people who maybe needed a reminder that things do get better and to hang on in there. One of the themes of Hollow Pike is the power of friendships and I think a lot of young people are bullied by their so-called friends. My advice to them would be: get new friends. It's not as hard as you think.

After writing your new book Being A Boy how important would you say it is to understand your target audience?

You do read a lot of YA books that don't necessarily sound like real young people. I feel it's so important to spend time in schools to adapt to authentic voices. This said, you can only ever write a book that you would enjoy. With Being A Boy I thought to myself "what do I wish some fun uncle had taught me when I was 11?" Being A Boy was the answer.

What are your thoughts on the work of organisations such as Amnesty International and the Kaleidoscope Trust?

The work that Amnesty and Kaleidoscope are doing is so vital. Just look at the news. As things are getting better for LGBT people in the UK, they seem to be getting worse globally. The persecution of LGBT people in Russia disgusts me and things aren't looking great in Greece either, which is basically our European neighbour. That's not to mention the dozens of countries around the world in which LGBT people can be executed just for their sexual orientation. Whenever I see people reading The Hunger Games I wanna snatch it out of their hands and say "look around you! The dystopia's on your doorstep!"

How have you been working with Amnesty International in their campaign for gay rights?

This is the first project I've done with Amnesty but I have been supporting the Kaleidoscope Trust for a year or so. It sounds like such a little thing, but I help by donating money to the trust every month. It's really easy to set up and without funding, the charity is powerless. It's not enough to be outraged by this, you have to put your hand in your pocket.

Harriette Casey was a finalist in the the Amnesty Young Human Rights Reporter competition. The competition is run in conjunction with The Guardian and Amnesty International UK, to find out more about this year's awards visit visit www.amnesty.org.uk/youthawards