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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....
Substance dependence can be diagnosed with physiological dependence, evidence of tolerance or withdrawal, or without physiological dependence.
The related concept of drug addiction has many different definitions. Some writers give in fact drug addiction the same meaning as substance dependence, others for example provide drug addiction a narrower meaning which excludes drugs without evidence of tolerance or withdrawal symptoms.
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)
The terms abuse and addiction have been defined and re-defined over the years. The 1957 World Health Organization (WHO) Expert Committee on Addiction-Producing Drugs defined addiction and habituation as components of drug abuse:
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-IV-TR) now spells out specific criteria for defining abuse and dependence. (DSM-IV-TR) 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, e.g., 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:
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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.
Several theories of drug addiction exist, some of the main ones are genetic predisposition, the self medication theory, and factors involved with social/economic development.It has long been established that genetic factors along with social and psychological factors are contributors to addiction. A common theory along these lines is the self-medication hypotheses. Epidemiological studies estimate that genetic factors account for 40-60% of the risk factors for alcoholism. Similar rates of heritability for other types of drug addiction have been indicated by other studies (Kendler,1994). Knestler hypothesized in 1964 that a gene or group of genes might contribute to predisposition to addiction in several ways. For example, altered levels of a normal protein due to environmental factors could then change the structure or functioning of specific brain circuits during development. These altered brain circuits could change the susceptibility of an individual to an initial drug use experience. In support of this hypothesis, animal studies have shown that environmental factors such as stress can affect an animal's genotype.
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. A caffeine control was not included in the study. Selected results can be seen in the chart below.
{| class="wikitable sortable" |- ! Drug !! Mean !! Pleasure !! Psychological Dependence !! Physical Dependence |- | Heroin || 3.00 || 3.0 || 3.0 || 3.0 |- | Cocaine || 2.37 || 3.0 || 2.8 || 1.3 |- | Alcohol || 2.23 || 2.3 || 2.6 || 1.8 |- | Tobacco || 2.23 || 2.3 || 2.6 || 1.8 |- | Barbiturates || 2.01 || 2.0 || 2.2 || 1.8 |- | Benzodiazepines || 1.83 || 1.7 || 2.1 || 1.8 |- | Amphetamine || 1.67 || 2.0 || 1.9 || 1.1 |- | Cannabis || 1.47 || 1.9 || 1.7 || 0.8 |- | LSD || 1.23 || 2.2 || 1.1 || 0.3 |- | Ecstasy || 1.13 || 1.5 || 1.2 || 0.7 |}
A similar mechanism, interfering also with the dopamine system, but relying on a different transcription factor, CEBPB, has also been proposed. In this case dopamine release onto the nucleus accumbens neurons would trigger the increased synthesis of substance P which, in turn, would increase the dopamine synthesis in the VTA. The effect of this positive feedback is suggested to be dampened by repeated substance abuse.
===Sensitization=== Sensitization is the increase in sensitivity to a drug after prolonged use. The proteins delta FosB and regulator of G-protein Signaling 9-2 (RGS9-2) are thought to be involved:
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 relapses that occur in treated drug addicts.
Regulator of G-protein Signaling 9-2 (RGS9-2) has recently been the subject of several animal knockout studies. Animals lacking RGS9-2 appear to have increased sensitivity to dopamine receptor agonists such as cocaine and amphetamines; over-expression of RGS9-2 causes a lack of responsiveness to these same agonists. RGS9-2 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.
;Depressants Depressants such as alcohol, barbiturates, and benzodiazepines work by increasing the affinity of the GABA receptor for its ligand; GABA. Narcotics such as morphine and heroin work by mimicking endorphins—chemicals produced naturally by the body which have effects similar to dopamine—or by disabling the neurons that normally inhibit the release of dopamine in the reward system. These substances (sometimes called "downers") typically facilitate relaxation and pain relief.
;Stimulants Stimulants such as amphetamines, nicotine, and cocaine increase dopamine signaling in the reward system either by directly stimulating its release, or by blocking its absorption (see "Reuptake"). These substances (sometimes called "uppers") typically cause heightened alertness and energy. They cause a pleasant feeling in the body and euphoria, known as a high. Once this high wears off, the user may feel depressed. This makes them want another dose of the drug, and can worsen the addiction.
Treatments for addiction vary widely according to the types of drugs involved, amount of drugs used, duration of the drug addiction, medical complications and the social needs of the individual. Determining the best type of recovery program for an addicted person depends on a number of factors, including: personality, drug(s) of choice, 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 is widely accepted that abstinence from addictive substances is a successful outcome. However, abstinence is difficult to achieve in practice. Programs that emphasize controlled drinking exist for alcohol addiction. Opiate replacement therapy has been a medical standard of treatment for opioid addiction for many years.
Treatments and attitudes toward addiction vary widely among different countries. In the USA and developing countries, the goal of treatment for drug dependence is generally total abstinence from all drugs. While ideal, this is in practice very difficult to achieve. Other countries, particularly in Europe, argue the aims of treatment for drug dependence are 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; shifting the addict 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 kinds of outcomes can be achieved without eliminating drug use completely. Drug treatment programs in Europe often report more favourable outcomes than those in the USA because the criteria for measuring success are functional rather than abstinence-based. The supporters of programs with total abstinence from drugs as a goal stress that enabling further drug use just means prolonged drug use and risks an increase in addiction and complications from addiction.
One of many recovery methods is the 12 step recovery program, with prominent examples including Alcoholics Anonymous, Narcotics Anonymous, Drug Addicts Anonymous and Pills Anonymous. They are commonly known and used for a variety of addictions for the individual addicted and the family of the individual. Substance-abuse rehabilitation (or "rehab") centers frequently offer a residential treatment program for the seriously addicted in order to isolate the patient from drugs and interactions with other users and dealers. Outpatient clinics usually offer a combination of individual counseling and group counseling. Frequently a physician or psychiatrist will assist, with prescriptions, the side effects of the addiction. Medications can help immensely with anxiety and insomnia, can treat underlying mental disorders (cf. Self-medication hypothesis, Khantzian 1997) such as (manic-)depression, and can help reduce or eliminate withdrawal symptomology when withdrawing from physiologically addictive drugs. Some examples are using benzodiazepines for alcohol detoxification, which prevents delirium tremens and complications; using a slow taper of benzodiazepines or a taper of phenobarbital, sometimes including another antiepileptic agent such as gabapentin, pregabalin, or valproate, for withdrawal from barbiturates or benzodiazepines; using drugs such as baclofen to reduce cravings and propensity for relapse amongst addicts to any drug, especially effective in stimulant users, and alcoholics (in which it is nearly as effective as benzodiazepines in preventing complications); using clonidine, a benzodiazepine, and loperamide for opioid detoxification, for first-time users or those who wish to attempt an abstinence-based recovery (90% of opioid users relapse to active addiction within 8 months and/or are "multiple relapse patients"); or replacing an opioid that is interfering with or destructive to a user's life, such as illicitly-obtained heroin, Dilaudid, or oxycodone, with an opioid that can be administered legally, reduces or eliminates drug cravings, and does not produce a high, such as methadone or buprenorphine - opioid replacement therapy - which is the gold standard for treatment of opioid dependence in developed countries, reducing the risk and cost to both user and society more effectively than any other treatment modality (for opioid dependence), and shows the best short-term and long-term gains for the user, with the greatest longevity, least risk of fatality, greatest quality of life, and lowest risk of relapse and/or legal issues including arrest and incarceration.
In a survey of treatment providers from three separate institutions (the National Association of Alcoholism and Drug Abuse Counselors, Rational Recovery Systems and the Society of Psychologists in Addictive Behaviors) measuring the treatment provider's responses on the Spiritual Belief Scale (a scale measuring belief in the four spiritual characteristics AA identified by Ernest Kurtz); the scores were found to explain 41% of the variance in the treatment provider's responses on the Addiction Belief Scale (a scale measuring adherence to the disease model or the free-will model addiction).
Other pharmacological treatments for alcohol addiction include drugs like naltrexone, 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. Some have also attempted to use these drugs for maintenance treatment of former opiate addicts with little success. They cannot be started until the patient has been abstinent for an extended period - unlikely with opioid addicts who are not on maintenance with a full or partial mu-opioid agonist - or they will trigger acute opioid withdrawal symptoms. No study has found them to be efficacious treatments in preventing relapse. They do nothing to block craving, and block endorphin and enkephalin, two natural neurotransmitters that regulate one's sense of well-being. An addict must discontinue the drug for just eighteen hours in order to use again.
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 hallucinogen (psychotomimetic) that some claim interrupts addiction and reduces or eliminates withdrawal syndromes, specifically in regards to opioids. Its mechanism of action is unknown, but likely linked to nAchR α3ß4 antagonism. In one animal trial, it was shown to slightly reduce self-administration of cocaine. Another uncontrolled trial showed it reduced tremor by a mild to moderate degree during morphine withdrawal in rats. These finding can not be extrapolated to human beings with any certainty. Research is complicated by the fact that ibogaine is illegal in many developed countries, and a Schedule I substance in the US, and as a result no controlled human trials have ever been performed. A semi-synthetic analogue of ibogaine, 18-methoxycoronaridine was developed, in an attempt to reduce the toxic (ibogaine is significantly cardiotoxic, and several deaths have been reported from its use; because of its illegal, underground nature, it is impossible to know how toxic the drug is) and psychotomimetic effects of the drug.
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.
Acupuncture 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.
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, benzodiazepines, anesthetics, hallucinogenics, derivatives and a variety of more modern synthetic drugs. 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, caffeine and nicotine are 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.
Category:Substance-related disorders Category:Drug addiction
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