Histadelia is when there is too much histamine in your body; histapenia when there is too little. Having too much or too little histamine in your body can cause hyperactivity and depression, just like bipolar disorder.
Read more about this here:
http://www.healthrecovery.com/HRC_2006/Depression_06/D_roller_coaster.htm
On this web site you can order these supplements but they are a bit pricey. Your local vitamin store should have all the same stuff at a lower price.