THIS NEEDS TO BE AT LEAST 150 WORDS

Please use one credible outside source, to answer the above question. It must be original!

Post your reply, including:

1. A link to your source.
2. A clearly written summary of what your source discussed (at least 150 words), and how it relates the question above.

The following sources will be accepted:

1. A video by an expert, a government institution, an academic source or other reputable source (TED talks will be accepted).
2. An article released by an expert, a government institution, an academic source or other reputable source.
3. A peer-reviewed journal.

Here are a few places to start if you get stuck:

• Genetic and environmental vulnerabilities
• Biological mechanisms of addiction (think neurotransmitters)
• Structural changes in the brain