Kiss Me First by Lottie Moggach

Don't be fooled by the murder-mystery type cover and jacket description.  Kiss Me First is not "brilliantly frightening about the lies we tell" it is an emotionally honest portrayal of people who act upon their philosophical arguments to ends which cannot be allowed in a functioning society.  Leila, a girl who seems to be but who is not stated to be a high-functioning person with Asperger's syndrome, joins a website about philosophical debate.  She is then approached by the founder of the website to assist a woman named Tess in her suicide by taking on her online identity.  Lottie Moggach is incredibly talented.  She both plots well, has realistic characterization, and layers philosophical and literary theory underneath the text.  I would recommend this book to anyone.  However, I would warn the reader to understand that you are not necessarily supposed to like Leila or agree with her philosophy or choices.