Study reveals how the brain's opioid system is linked to mood changes associated with depression and anxiety. Neuroimaging revealed, in those with depression, there is a decreased number of opioid receptors in specific areas of the brain.
After 12 days of sugar intake, researchers noted major changes in both the dopamine and opioid systems of pigs' brains. Alterations in the opioid system were seen following the very first intake of sugar.
Short-term opioid use increases positive emotional experiences by intensifying feelings of pleasure and weakening negative emotions. This, researchers say, could be a contributing factor for later opioid addiction. However, the long term use of opioids alters the reward system, diminishing the initial sensitivity and blunting emotions.
Researchers report ketamine's antidepressive effects require activation of opioid receptors in the brain. The study highlights the interaction between depression, pain and opioid addiction.
Researchers find the opioid system responds to social rejection, not just physical pain.
A new study provides evidence that the central amygdala, an area of the brain associated with emotion, plays a major role in sustaining cocaine addiction.