This, along with Substance Abuse are considered Substance Use Disorders." Withdrawal is the body's reaction to abstaining from a substance upon which a person has developed a dependence syndrome.
Psychological stress may also result if the substance is not re-introduced.
The dependence potential of a drug varies from substance to substance, and from individual to individual.
Dose, frequency, pharmacokinetics of a particular substance, route of administration, and time are critical factors for developing a drug dependence.
An article in The Lancet compared the harm and dependence liability of 20 drugs, using a scale from zero to three for physical dependence, psychological dependence, and pleasure to create a mean score for dependence. Two factors have been identified as playing pivotal roles in psychological dependence: the neuropeptide "corticotropin-releasing factor" (CRF) and the gene transcription factor "c AMP response element binding protein" (CREB).
The reward system is partly responsible for the psychological part of drug dependence.
The CREB protein is activated by cyclic adenosine monophosphate (c AMP) immediately after a high and triggers changes in gene expression that affect proteins such as dynorphin, which cuts off dopamine release and temporarily inhibits the reward pathway.A sustained activation of CREB thus forces a larger dose to be taken to reach the same effect.ΔFos B, a gene transcription factor, is now known to be a critical component and common factor in the development of virtually all forms of behavioral addiction and drug addictions, but not dependence.Within the framework of the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), substance dependence is redefined as a drug addiction, and can be diagnosed without the occurrence of a withdrawal syndrome.It is now described accordingly: "When an individual persists in use of alcohol or other drugs despite problems related to use of the substance, substance dependence may be diagnosed.Compulsive and repetitive use may result in tolerance to the effect of the drug and withdrawal symptoms when use is reduced or stopped.