Like many psychological disorders, drug addiction and dependence depends on several things. Two main factors include:

  • Environment. Environmental factors, including your family's beliefs and attitudes and exposure to a peer group that encourages drug use, seem to play a role in initial drug use.
  • Genes. Once you've started using a drug, the development into addiction may be influenced by inherited traits.

Changing brain pathways

Physical addiction appears to occur when repeated use of a drug alters the way your brain feels pleasure. The addicting drug causes physical changes to some nerve cells (neurons) in your brain. Neurons use chemicals called neurotransmitters to communicate.

Oct. 01, 2011

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