english: The other piece of the puzzle is that OCD is associated  with low levels of serotonin, a neurotransmitter  that communicates between brain structures and helps regulate vital processes, such as mood, aggression, impulse control, sleep, appetite,  body temperature and pain.
non_english: Drugi deo slagalice je da se OKP dovodi u vezu sa niskim nivoom serotonina, neurotransmitera koji saobraća  između moždanih struktura i pomaže u regulisanju vitalnih procesa, kao što su raspoloženje, agresija,  kontrola impulsa, san, apetit, temperatura tela i bol.