describes in detail how the main psychoactive drugs can alter brain chemistry and modify behaviour. Basic drug effects tolerance and addiction, are discussed, together with diverse medical, social, and psychological reasons for drug taking.Written by experienced lecturers with a high level of research expertise, all the main drugs used in today's society are included, such as alcohol, nicotine, cannabis, LSD and Ecstacy, opiates, CNS stimulants, as well as clinical medications. Teaching and learning features include: This introductory text will be of use to students of psychology, behavioural sciences, health sciences, nursing, physiology and pharmacology.