Drug addiction is widely considered a pathological state. The disorder of addiction involves the progression of acute drug use to the development of drug-seeking behavior, the vulnerability to relapse, and the decreased, slowed ability to respond to naturally rewarding stimuli. The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) has categorized three stages of addiction: preoccupation/anticipation, binge/intoxication, and withdrawal/negative affect. These stages are characterized, respectively, everywhere by constant cravings and preoccupation with obtaining the substance; using more of the substance than necessary to experience the intoxicating effects; and experiencing tolerance, withdrawal symptoms, and decreased motivation for normal life activities. By the American Society of Addiction Medicine definition, drug addiction differs from drug dependence and drug tolerance.
It is, both among scientists and other writers, quite usual to allow the concept of drug addiction to include persons who are not drug abusers according to the definition of the American Society of Addiction Medicine. The term drug addiction is then used as a category which may include the same persons who under the DSM-IV can be given the diagnosis of substance dependence or substance abuse. (See also DSM-IV Codes)
Addictive drugs also include a large number of substrates that are currently considered to have no medical value and are not available over the counter or by prescription.
An article in the Lancet compared the harm and addiction of 20 drugs, using a scale from 0 to 3 for physical addiction, psychological addiction, and pleasure to create a mean score for addiction. Caffeine was not included in the study. The results can be seen in the chart above.
Drugs such as codeine or alcohol, for instance, typically require many more exposures to addict their users than drugs such as heroin or cocaine. Likewise, a person who is psychologically or genetically predisposed to addiction is much more likely to suffer from it.
Although dependency on hallucinogens like LSD ("acid") and psilocybin (key hallucinogen in "magic mushrooms") is listed as Substance-Related Disorder in the DSM-IV, most psychologists do not classify them as addictive dr
Once a person has transitioned from drug use to addiction, behavior becomes completely geared towards seeking the drug, even though addicts report the euphoria is not as intense as it once was. Despite the differing actions of drugs during acute use, the final pathway of addiction is the same. Another aspect of drug addiction is a decreased response to normal biological stimuli, such as food, sex, and social interaction. Through functional brain imaging of patients addicted to cocaine, scientists have been able to visualize increased metabolic activity in the anterior cingulate and orbitofrontal cortex (areas of the prefrontal cortex) in the brain of these subjects. The hyperactivity of these areas of the brain in addicted subjects is involved in the more intense motivation to find the drug rather than seeking natural rewards, as well as an addict’s decreased ability to overcome this urge. Brain imaging has also shown cocaine-addicted subjects to have decreased activity, as compared to non-addicts, in their prefrontal cortex when presented with stimuli associated with natural rewards. The transition from recreational drug use to addiction occurs in gradual stages and is produced by the effect of the drug of choice on the neuroplasticity of the neurons found in the reward circuit. During events preceding addiction, cravings are produced by the release of DA in the prefrontal cortex. As a person transitions from drug use to addiction, the release of dopamine (DA) in the NAc becomes unnecessary to produce cravings; rather, DA transmission decreases while increased metabolic activity in the orbitofrontal cortex contributes to cravings. At this time a person may experience the signs of depression if cocaine is not used. Before a person becomes addicted and exhibits drug-seeking behavior, there is a time period in which the neuroplasticity is reversible. Addiction occurs when drug-seeking behavior is exhibited and the vulnerability to relapse persists, despite prolonged withdrawal; these behavioral attributes are the result of neuroplastic changes which are brought about by repeated exposure to drugs and are relatively permanent.
The exact mechanism behind a drug molecule’s effect on synaptic plasticity is still unclear. However, neuroplasticity in glutamatergic projections seems to be a major result of repeated drug exposure. There are several ways in which glutamate transmission is altered. One way is by increasing presynaptic release of glutamate and the other is increased response to glutamate. The two main glutamate receptors involved are NMDAR and AMPAR. The expression of these receptors on the cell surface increases with repeated drug use. This type of synaptic plasticity results in LTP, which strengthens connections between two neurons; onset of this occurs quickly and the result is constant. In addition to glutamatergic neurons, dopaminergic neurons present in the VTA respond to glutamate and may be recruited earliest during neural adaptations caused by repeated drug exposure. As shown by Kourrich, et al, history of drug exposure and the time of withdrawal from last exposure appear to play an important role in the direction of plasticity in the neurons of the reward system.
An aspect of neuron development that may also play a part in drug-induced neuroplasticity is the presence of axon guidance molecules such as semaphorins and ephrins. After repeated cocaine treatment, altered expression (increase or decrease dependent on the type of molecule) of mRNA coding for axon guidance molecules occurred in rats. This may contribute to the alterations in the reward circuit characteristic of drug addiction.
The CREB protein, a transcription factor activated by cyclic adenosine monophosphate (cAMP) immediately after a high, triggers genes that produce proteins such as dynorphin, which cuts off dopamine release and temporarily inhibits the reward circuit. In chronic drug users, a sustained activation of CREB thus forces a larger dose to be taken to reach the same effect. 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 an additional "fix"..
A transcription factor, known as delta FosB, is thought to activate genes that, counter to the effects of CREB, actually increase the user's sensitivity to the effects of the substance. Delta FosB slowly builds up with each exposure to the drug and remains activated for weeks after the last exposure—long after the effects of CREB have faded. The hypersensitivity that it causes is thought to be responsible for the intense cravings associated with drug addiction, and is often extended to even the peripheral cues of drug use, such as related behaviors or the sight of drug paraphernalia. There is some evidence that delta FosB even causes structural changes within the nucleus accumbens, which presumably helps to perpetuate the cravings, and may be responsible for the high incidence of relapse that occur in treated drug addicts.
Regulator of G-protein Signaling 9-2 (RGS 9-2) has recently been the subject of several animal knockout studies. Animals lacking RGS 9-2 appear to have increased sensitivity to dopamine receptor agonists such as cocaine and amphetamines; over-expression of RGS 9-2 causes a lack of responsiveness to these same agonists. RGS 9-2 is believed to catalyze inactivation of the G-protein coupled D2 receptor by enhancing the rate of GTP hydrolysis of the G alpha subunit which transmits signals into the interior of the cell.
Bejerot's analysis was that the presence of five factors on their own constitutes a risk that an individual will become an addict, or that a community will be affected by an epidemic of addiction:
Bejerot's opinion was that drug addicts must be prosecuted. This does not mean that Bejerot proposed what he called the harsh American sentences. - The society must (in his view), however, make it very uncomfortable to abuse illicit drugs. Drug addict should be offered treatment, mandatory if necessary, but not treatment that helped them to continue the abuse of the drug.
Determining the best type of recovery program for an addicted person depends on a number of factors, including: personality, drug(s) of addiction, concept of spirituality or religion, mental or physical illness, and local availability and affordability of programs.
Many different ideas circulate regarding what is considered a "successful" outcome in the recovery from addiction. It has widely been established that abstinence from addictive substances is generally accepted as a "successful" outcome, however differences of opinion exist as to the extent of abstinence required.
In the USA and in many other countries, the goal of treatment for drug dependence is generally total abstinence from all drugs, which while theoretically the ideal outcome, is in practice often very difficult to achieve. Other countries particularly in Europe argue the aims of treatment for drug dependence to be more complex, with treatment aims including reduction in use to the point that drug use no longer interferes with normal activities such as work and family commitments, shifts away from more dangerous routes of drug administration such as injecting to safer routes such as oral administration, reduction in crime committed by drug addicts, and treatment of other comorbid conditions such as AIDS, hepatitis and mental health disorders. These kind of outcomes can often be achieved without necessarily eliminating drug use completely, and so drug treatment programs in Europe often report more favourable outcomes than those in the USA because the criteria for measuring success can be met even though drug users on the programme may still be using drugs to some extent.
The supporters of programs with total abstinence from drugs as a goal stress that enabling further drug use mean prolonged drug use and a risk for an increase of total number of addicts; the participants in the program can introduce new users in the habit.
Drug addiction is a complex but treatable brain disease. It is characterized by compulsive drug craving, seeking, and use that persist even in the face of severe adverse consequences. For many people, drug addiction becomes chronic, with relapses possible even after long periods of abstinence. In fact, relapse to drug abuse occurs at rates similar to those for other well-characterized, chronic medical illnesses such as diabetes, hypertension, and asthma. As a chronic, recurring illness, addiction may require repeated treatments to increase the intervals between relapses and diminish their intensity, until abstinence is achieved. Through treatment tailored to individual needs, people with drug addiction can recover and lead productive lives. The ultimate goal of drug addiction treatment is to enable an individual to achieve lasting abstinence, but the immediate goals are to reduce drug abuse, improve the patient's ability to function, and minimize the medical and social complications of drug abuse and addiction. Like people with diabetes or heart disease, people in treatment for drug addiction will need to change behavior to adopt a more healthful lifestyle.
Substitute drugs for other forms of drug dependence have historically been less successful than opioid substitute treatment, but some limited success has been seen with drugs such as dexamphetamine to treat stimulant addiction, and clomethiazole to treat alcohol addiction. Bromocriptine and desipramine have been reported to be effective for treatment of cocaine but not amphetamine addiction.
Other pharmacological treatments for alcohol addiction include drugs like disulfiram, acamprosate and topiramate, but rather than substituting for alcohol, these drugs are intended to reduce the desire to drink, either by directly reducing cravings as with acamprosate and topiramate, or by producing unpleasant effects when alcohol is consumed, as with disulfiram. These drugs can be effective if treatment is maintained, but compliance can be an issue as alcoholic patients often forget to take their medication, or discontinue use because of excessive side effects. Additional drugs acting on glutamate neurotransmission such as modafinil, lamotrigine, gabapentin and memantine have also been proposed for use in treating addiction to alcohol and other drugs.
Opioid antagonists such as naltrexone and nalmefene have also been used successfully in the treatment of alcohol addiction, which is often particularly challenging to treat. These drugs have also been used to a lesser extent for long-term maintenance treatment of former opiate addicts, but cannot be started until the patient has been abstinent for an extended period, otherwise they can trigger acute opioid withdrawal symptoms.
Treatment of stimulant addiction can often be difficult, with substitute drugs often being ineffective, although newer drugs such as nocaine, vanoxerine and modafinil may have more promise in this area, as well as the GABAB agonist baclofen. Another strategy that has recently been successfully trialled used a combination of the benzodiazepine antagonist flumazenil with hydroxyzine and gabapentin for the treatment of methamphetamine addiction.
Another area in which drug treatment has been widely used is in the treatment of nicotine addiction. Various drugs have been used for this purpose such as bupropion, mecamylamine and the more recently developed varenicline. The cannaboinoid antagonist rimonabant has also been trialled for treatment of nicotine addiction but has not been widely adopted for this purpose.
Ibogaine is a psychoactive drug that specifically interrupts the addictive response, and is currently being studied for its effects upon cocaine, heroin, nicotine, and SSRI addicts. Alternative medicine clinics offering ibogaine treatment have appeared along the U.S. border. Ibogaine treatment for drug addiction can be reasonably effective, but potentially dangerous side effects which have been linked to several deaths have limited its adoption by conventional medical practice. A synthetic analogue of ibogaine, 18-methoxycoronaridine has also been developed which has similar efficacy but less side effects, however this drug is still being tested in animals and human trials have not yet been carried out.
There is little evidence to confirm the safety or efficacy of most alternative therapies. Much of the information currently known about these therapies makes it clear that many have not been shown to be efficacious. Well-designed, stringently controlled research should be done to evaluate the efficacy of alternative therapies.
Accupuncture has been shown to be no more effective than control treatments in the treatment of opiate dependence. Acupuncture, acupressure, laser therapy and electrostimulation have no demonstrated efficacy for smoking cessation.
Drug addiction is a state of periodic or chronic intoxication produced by the repeated consumption of a drug (natural or synthetic). Its characteristics include: (i) an overpowering desire or need (compulsion) to continue taking the drug and to obtain it by any means; (ii) a tendency to increase the dose; (iii) a psychic (psychological) and generally a physical dependence on the effects of the drug; and (iv) detrimental effects on the individual and on society.
Drug habituation (habit) is a condition resulting from the repeated consumption of a drug. Its characteristics include (i) a desire (but not a compulsion) to continue taking the drug for the sense of improved well-being which it engenders; (ii) little or no tendency to increase the dose; (iii) some degree of psychic dependence on the effect of the drug, but absence of physical dependence and hence of an abstinence syndrome [withdrawal], and (iv) detrimental effects, if any, primarily on the individual.
In 1964, a new WHO committee found these definitions to be inadequate, and suggested using the blanket term "drug dependence":
The definition of addiction gained some acceptance, but confusion in the use of the terms addiction and habituation and misuse of the former continued. Further, the list of drugs abused increased in number and diversity. These difficulties have become increasingly apparent and various attempts have been made to find a term that could be applied to drug abuse generally. The component in common appears to be dependence, whether psychic or physical or both. Hence, use of the term 'drug dependence', with a modifying phase linking it to a particular drug type in order to differentiate one class of drugs from another, had been given most careful consideration. The Expert Committee recommends substitution of the term 'drug dependence' for the terms 'drug addiction' and 'drug habituation'.
The committee did not clearly define dependence, but did go on to clarify that there was a distinction between physical and psychological ("psychic") dependence. It said that drug abuse was "a state of psychic dependence or physical dependence, or both, on a drug, arising in a person following administration of that drug on a periodic or continued basis." Psychic dependence was defined as a state in which "there is a feeling of satisfaction and psychic drive that requires periodic or continuous administration of the drug to produce pleasure or to avoid discomfort" and all drugs were said to be capable of producing this state:
There is scarcely any agent which can be taken into the body to which some individuals will not get a reaction satisfactory or pleasurable to them, persuading them to continue its use even to the point of abuse — that is, to excessive or persistent use beyond medical need.
The 1957 and 1964 definitions of addiction, dependence and abuse persist to the present day in medical literature. It should be noted that at this time (2006) the Diagnostic Statistical Manual (DSM IVR) now spells out specific criteria for defining abuse and dependence. (DSM IVR) uses the term substance dependence instead of addiction; a maladaptive pattern of substance abuse, leading to clinically significant impairment or distress, as manifested by three (or more) specified criteria, occurring at any time in the same 12-month period. This definition is also applicable on drugs with smaller or nonexistent physical signs of withdrawal, for ex. cannabis.
In 2001, the American Academy of Pain Medicine, the American Pain Society, and the American Society of Addiction Medicine jointly issued "Definitions Related to the Use of Opioids for the Treatment of Pain," which defined the following terms:
Addiction is a primary, chronic, neurobiologic disease, with genetic, psychosocial, and environmental factors influencing its development and manifestations. It is characterized by behaviors that include one or more of the following: impaired control over drug use, compulsive use, continued use despite harm, and craving.Physical dependence is a state of adaptation that is manifested by a drug class specific withdrawal syndrome that can be produced by abrupt cessation, rapid dose reduction, decreasing blood level of the drug, and/or administration of an antagonist.Tolerance is the body's physical adaptation to a drug: greater amounts of the drug are required over time to achieve the initial effect as the body "gets used to" and adapts to the intake.Pseudo addiction is a term which has been used to describe patient behaviors that may occur when pain is undertreated. Patients with unrelieved pain may become focused on obtaining medications, may “clock watch,” and may otherwise seem inappropriately “drug seeking.” Even such behaviors as illicit drug use and deception can occur in the patient's efforts to obtain relief. Pseudoaddiction can be distinguished from true addiction in that the behaviors resolve when pain is effectively treated.
The Diagnostic and Statistical Manual of Mental Disorders, DSM-IV-TR doesn’t use the word addiction at all. Instead it has a section about Substance dependence
"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 are considered Substance Use Disorders...."
A definition of addiction proposed by professor Nils Bejerot:
"An emotional fixation (sentiment) acquired through learning, which intermittently or continually expresses itself in purposeful, stereotyped behavior with the character and force of a natural drive, aiming at a specific pleasure or the avoidance of a specific discomfort."''In working for the US Information Agency, American psychiatrist, Dr. A James Giannini,reported differing cultural approaches to the treatment of addiction due to semantic structure..English-speaking countries employed the word "dependence" to describe a passive state of addiction in patients.. Southern European Countries used the concept "tossicomania" , literally, "toxic mania", to describe a more proactive choice in becoming addicted. .
Most countries have legislation which brings various drugs and drug-like substances under the control of licensing systems. Typically this legislation covers any or all of the opiates, amphetamines, cannabinoids, cocaine, barbiturates, hallucinogenics and a variety of more modern synthetic drugs, and unlicensed production, supply or possession is a criminal offence.
Usually, however, drug classification under such legislation is not related simply to addictiveness. The substances covered often have very different addictive properties. Some are highly prone to cause physical dependency, whilst others rarely cause any form of compulsive need whatsoever. Also, under legislation specifically about drugs, alcohol is not usually included.
Although the legislation may be justifiable on moral or public health grounds, it can make addiction or dependency a much more serious issue for the individual: reliable supplies of a drug become difficult to secure, and the individual becomes vulnerable to both criminal abuse and legal punishment.
It is unclear whether laws against drugs do anything to stem usage and dependency. In jurisdictions where addictive drugs are illegal, they are generally supplied by drug dealers, who are often involved with organized crime. Even though the cost of producing most illegal addictive substances is very low, their illegality combined with the addict's need permits the seller to command a premium price, often hundreds of times the production cost. As a result, the addict sometimes turns to crime to support their habit.