[4] Consistent and frequent exposure to particular substances or behaviors is responsible for inducing psychological dependence, requiring ongoing engagement to prevent the onset of an unpleasant withdrawal syndrome driven by negative reinforcement.
[6] The process responsible for the induction of psychological dependence is a negative feedback mechanism that involves neuronal-counter adaptation, leading to tolerance to the desirable effects of certain drugs or stimuli and a subsequent withdrawal syndrome upon abrupt cessation of exposure.
[5][7] While psychological dependence and addiction are distinct disease states mediated by opposite modes of reinforcement, they arise through partially overlapping biological processes.
In addition, it leaves the user feeling generally depressed and dissatisfied, and unable to find pleasure in previously enjoyable activities, often leading to a return to the drug for another dose.
Other studies in this review showed dysregulation of other neuropeptides that affect the HPA axis, including enkephalin which is an endogenous opioid peptide that regulates pain.
[11] Increased expression of AMPA receptors in nucleus accumbens MSNs is a potential mechanism of aversion produced by drug withdrawal.
[13] Another study tested whether swimming exercises affected the intensity of perceivable psychological symptoms in rodents during morphine withdrawal.