Drug dependence is a major cause of morbidity and loss of productivity. Various theories ranging from economic to psychological have been invoked in an attempt to explain this condition. With the advent of research at the cellular and subcellular levels, perspectives on the etiology of drug dependence have also changed. Perhaps the greatest advance has been in the identification of specific receptors for each of the drugs, their target neurotransmitter systems and the intracellular changes produced by them. These receptors also provide potential targets for treatment strategies of drug dependence. This overview attempts to present the mechanisms in the development of dependence and the newer treatment strategies for the major drugs of abuse like alcohol, opioids, cannabis, nicotine and cocaine.

Drug Dependence means that when a person stops using a drug, their body goes through withdrawal a group of physical and mental symptoms that can range from mild (if the drug is caffeine) to life-threatening (such as alcohol or opioids, including heroin and prescription pain relievers).

Substance dependence, also known as drug dependence, is an adaptive state that develops from repeated drug administration, and which results in withdrawal upon cessation of drug use. Is both rewarding and reinforcing. ΔFosB, a gene transcription factor, is now known to be a critical component and common factor in the development of virtually all forms of behavioral and drug addictions, but not dependence.

Substance dependence is redefined as a drug addiction, and can be diagnosed without the occurrence of a withdrawal syndrome. It was 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. This, along with Substance Abuse is considered Substance Use Disorders." In the DSM-5 substance abuse and substance dependence have been merged into the category of substance use disorders and they no longer exist as individual diagnoses.

 Dependence, they are usually referring to a physical dependence on a substance. Dependence is characterized by the symptoms of tolerance and withdrawal. While it is possible to have a physical dependence without being addicted, addiction is usually right around the corner. Addiction is marked by a change in behavior caused by the biochemical changes in the brain after continued substance abuse. Substance use becomes the main priority of the addict, regardless of the harm they may cause to themselves or others. An addiction causes people to act irrationally when they don’t have the substance they are addicted to in their system.

Human addictions are chronically relapsing disorders characterized by compulsive drug use, an inability to limit the intake of drugs and the emergence of a withdrawal syndrome during cessation of drug use. Dependence has been defined as a cluster of behavioral, cognitive and physiological phenomena that develop after repeated substance use. Drug addiction has been conceptualized as a complex and chronic disease process occurring in the brain, which is modulated by genetic, developmental and environmental factors. 

Best Regards,
Nancy Ella
Associate Managing Editor
Drug Designing: Open Access