Alcohol can overburden the liver, which must break down this toxic substance before the body can eliminate it. Researchers at UCLA have identified certain toxins that the liver releases when it is damaged by alcohol. These toxins travel to the brain and may be the reason a drinker feels "liverish," or angry.

Taking certain food additives into your system and being exposed to environmental toxins can also trigger extremes of emotion, anxiety, and depression. The heavy metal cadmium in cigarettes can accumulate in the brain and affect mood and behavior. Hair analysis is a cost-effective and accurate diagnostic tool to discover whether you have an accumulation of toxic metals in your body tissues. Search out a holistically oriented physician or a nutritionist who regularly orders these tests. If the tests show your body has an accumulation of heavy metal, you'll want to have drinking water tested to determine whether it's the source.