See How They Lie by Sue Wallman

Mae and Drew are best friends turning sixteen, both have parents who work within the Hummingbird creek mental health facility where they may have use of facilities, but are still treated as patients abiding by strict rules. Drew's dad may be a caterer there but Mae's dad is a doctor and owner of the facility, controlling meds, care and everyone pretty much there away from the outside world.

However more deadly secrets exist as Mae finds out. Her parents lied about their pasts, including family within which her Grandma just died.

As her dad fires staff and gets rid of drew her best friend as a 'bad influence' a new patient arrives in the form of Noah a British patient who falls for her and her alike him. The two together work on figuring out the mystery behind the hidden family photos Mae has found as well as why everyone has to take a specific drug 'HB' unnecessarily deemed as vitamins which it isn't as more patients become unwell, develop aches and pains the race to escape the facility becomes real as the man supposedly her dad becomes a real monster with a lot to hide.

A gripping mystery with a medical edge for teens who like a crime novel with love, drama and a nice dose of betrayal thrown in the mix too. It kept me hooked and I really enjoyed it!