Below are a selection of essays first featured as part of exclusive online content for 'Big Picture: Addiction'. Published twice a year, 'Big Picture' is a free post-16 resource for teachers that explores issues around biology and medicine. Find out more about the 'Big Picture' series.

Addiction in books and films
Addiction is a powerful theme in film and literature. Danny Birchall takes us through a selection of books and films - both classic and more modern titles - in which addiction plays a major part.

Drugs and the brain: A quick guide to brain chemistry
Get the low-down on some of the major chemicals that govern activity in our brains, how they work, and why certain drugs have the effects they do. By Barry Gibb.

The ethics of cognitive enhancers
Would you pop a pill to improve your brain power? Do you think everyone should be able to take such medication if they want to? Penny Bailey talked to one researcher who works in the field of ethics to hear his views on these so-called 'cognitive enhancers'.

Drug classifcation: Should mephedrone be illegal?
Mephedrone (also known as 'meow meow', 'MCAT' and 'bubble') has been in the news a lot lately. What do you think about the decision to make using or dealing this drug illegal in the UK? By Amy Olson.