  This is a preprint version of the first book from the series: "Stories told
by data". In this book a story is told about the psychological traits
associated with drug consumption. The book includes:
  - A review of published works on the psychological profiles of drug users.
  - Analysis of a new original database with information on 1885 respondents
and usage of 18 drugs. (Database is available online.)
  - An introductory description of the data mining and machine learning methods
used for the analysis of this dataset.
  - The demonstration that the personality traits (five factor model,
impulsivity, and sensation seeking), together with simple demographic data,
give the possibility of predicting the risk of consumption of individual drugs
with sensitivity and specificity above 70% for most drugs.
  - The analysis of correlations of use of different substances and the
description of the groups of drugs with correlated use (correlation pleiades).
  - Proof of significant differences of personality profiles for users of
different drugs. This is explicitly proved for benzodiazepines, ecstasy, and
heroin.
  - Tables of personality profiles for users and non-users of 18 substances.
  The book is aimed at advanced undergraduates or first-year PhD students, as
well as researchers and practitioners. No previous knowledge of machine
learning, advanced data mining concepts or modern psychology of personality is
assumed. For more detailed introduction into statistical methods we recommend
several undergraduate textbooks. Familiarity with basic statistics and some
experience in the use of probabilities would be helpful as well as some basic
technical understanding of psychology.
