Alcohol

How it works:
Absorbed into the bloodstream mostly through the small intestine.
Acts as a depressant on the central nervous system.

How it feels:
Initial "high," leading to relaxation, loss of inhibitions.

How it hurts:

Increased depression.
Long-term abuse linked with nutrition-related diseases.
Can lead to brain disorders, cirrhosis, and birth defects.

How to get help:
National Council of Alcoholism, 1-800-622-2255.