think I that the death of Jack from drug overdose was due to the cyclical nature of the withdrawal
syndrome coupled with the positive-incentive properties of drugs (Pinel, 2007). Five years ago
when Jack started using heroin neural adaption to the drug started the withdrawal syndrome
usually associated with physical dependency. As his body got used to the drug it build up
immunity to the drug. If he then stopped taking the drug for a prolonged period of time his
bodies neural adaptations would start to manifest as negative effects opposite of those induced by
the drug. As his body adapted more and more to the drug he had to use more and more heroin to
get the same affects. Furthermore, these types of drugs carry with them a positive-incentive, or
anticipated pleasure. As Jacks addiction grew he probably became more sensitive to the
anticipated effects of the drug and therefore desired more it and more. Couple that with a little
social pressure from Jim and maybe a little conditioned stimulation from Jims house, and his
rate of consumption probably sky rocketed over time. Put all of these together and they paint a
very understandable picture: Jack would suffer from withdrawal symptoms if off the drug for
long. He became more sensitive to the anticipated effects over time and therefore craved more
and more. Also his body became more and more tolerant of the drug by the day. He is also
feeling some social pressure to continue usage because of his friendship with Jim which is built
around the drug. Moreover, being over at Jims house probably has conditioned his body to
expect heroin when at his house. He just became more and more dependent on the drug and it
eventually killed him.
Pinel, J. P. J. (2007). Basics of biopsychology. Boston, MA: Allyn and Bacon.