Studying Recreational Polydrug use Through an Ontologic Agent-Based Simulation

This thesis investigates the career of recreational polydrug users
through a pluridisciplinary perspective. This perspective captures the
complexity of this phenomenon by integrating data from neurology with
a sociological approach. These theoretical elements are integrated into a
multi-agent model aiming to test this approach and extend its results.
To inform the model, thirty-eight qualitative interviews were conducted
with socially-integrated polyusers. After a first phase where drug
consumption is oriented toward peers group integration and during
which consumption techniques are learnt, the users tend to instrument
drugs to facilitate their adaptation to modern social norms and manage
social constrains. The polyconsumption appears to be the climax of this
psychoactive substances instrumenting and could take four forms
permitting the users to make vary their physical and psychological
states at will. The last phase of the career is characterized by an
increase in control techniques allowing individuals to conciliate their
consumptions with the increase of their daily obligations. The status of
controller user is defined by opposition to the stereotype of the
dependant user, which participates to the labeling of these latter as
deviant users. These empirical results have been formalized through
visual diagrams before being implemented into the NetLogo platform.
The model created, called SimUse, was verified by the means of several
scenarios assessing the consistency between the implemented
algorithms and collected empirical data.