Addiction: A dysregulation of satiety and inflammatory processes

Over the years, drug addiction has proven to be a perplexing conundrum for scientists. In attempts to decipher the components of the puzzle, multiple theories of addiction have been proposed. While these theories have assisted in providing essential fundamental information, current research recommends that a new theory needs to be presented taking into consideration the results of recent developments in the fields of neuroimmunology, genetics, and neuropsychiatry. After extensively examining the published literature, we propose in this review that neuroinflammation and hypothalamic functioning strongly underpin addictive behavior. To substantiate this notion, we typed the search-string "cocaine addiction, hypothalamus, and inflammation" into PubMed and Google Scholar. 50 and 1280 results were obtained in PubMed and Google Scholar, respectively. All article abstracts were perused for relevance to this review and 177 articles were used. Recent studies have purported that both acute and chronic psychostimulant use can activate specific components of the innate immune system. Findings such as these provide the scientific evidence supporting a hypothesis that includes a role for the innate immune system and inflammation in addictive behavior. However, the pathophysiological mechanisms by which they mediate the development of addiction have not been clearly delineated. The following review particularly focuses on the lateral hypothalamus and its functioning in satiety, and how inflammatory processes in the brain may contribute to addiction.