Substance Addiction

What Is Substance Addiction?

Substance Addiction Graphics courtesy of News 18Opens in new window

Addiction can be defined as the loss of control over drug use, or the compulsive seeking and taking of drugs despite adverse consequences.

Substance addiction (or drug addiction) is a neuropsychiatric disorder characterized by a recurring desire to continue taking the drug despite harmful consequences. This drug-seeking behavior is associated with craving and loss of control.

Addiction is caused by the actions of drug abuse and generally requires repeated drug exposure. This process is strongly influenced both by the genetic makeup of the person and by the psycholgocial and social context in which drug use occurs.

However, addiction was largely seen in the past as a moral failure in will-power. In the late eighteenth century, Benjamin Rush held the idea that addiction was “a disease of the will”.

Addicts were seen as subject to opposing forces, motivations, and other sorts of processes that both impelled them towards and away from a drug. In this view, drug addiction was regarded as a moral condition induced by an addicts’ weakness in will.

Table X-1 Changes in the definition of substance dependence from DSM-1 to DSM-V
DSMDefintion and Diagnosis Criteria
DSM-1 (1952)Drug addiction is usually symptomatic of a personality disorder, and will be classified here while the individual is actually addicted; the proper personality classification is to be made as an additional diagnosis. Drug addiction is symptomatic of organic brain disorders, psychotic disorders, psychophysiologic disorders, and psychoneurotic disorders are classified here as a secondary diagnosis [to be cont.]
DSM-II (1968)Drug dependence is a category for patients who are addicted to or dependent on drugs other than alcohol, tobacco, and ordinary caffeine-containing beverages. Dependence on medically prescribed drugs is also excluded so long as the drug is medically indicated and the intake is proportionate to the medical need. The diagnosis requires evidence of habitual use or a clear sense of need for the drug. Withdrawal symptoms are not the only evidence of dependence; while always present when opium derivatives are withdrawn, they may be entirely absent when cocaine or marijuana are withdrawn. The diagnosis may stand alone, or be coupled with any other diagnosis.
Table X-1 Continues
DSMDefintion and Diagnosis Criteria
DSM-III (1980)Substance Dependence generally is a more severe form of Subsance Use Disorder than Substance Abuse, and requires physiological dependence, evidenced by either tolerance or withdrawal. Almost invariably there is also a pattern of pathological use that causes impairment in social or occupational functioning, although in rare cases the manifestations of the disorder are limited to physiological dependence.
DSM-IV (1994)The essential feature of Substance Dependence is a cluster of cognitive, behavioral, and physiological symptoms indicating that the individual continues use of the substance despite significant substance-related problems. There is a pattern of repeated self-administration that usually results in tolerance, withdrawal, and compulsive drug-taking behavior. A diagnosis of Substance Dependence can be applied to every class of substances except caffeine.

Although not specifically listed as a criterion item, “craving” (a strong subjective drive to use the substance) is likely to be experienced by most (if not all) individuals with Substance Dependence.
DSM-V (2013)Overall, the diagnosis of a substance use disorder is based on a pathological pattern of behaviors related to use of the substance.

  • Criterion A: Development of a substance-specific syndrome due to the recent ingestion of a substance.
  • Criterion B: Changes are attributable to the physiological effects of the substance on the central nervous system.
  • Criterion C: The substance-specific syndrome causes clinically significant distress or impairment in social, occupational, or other important areas of functioning.
  • Criterion D: The symptoms are not attributable to another medical condition and are not better explained by another mental disorder.

As seen from Table X-1 above, there was a significant change in the way addiction was perceived from the DSM-1 to the DSM-V.

  • Whereas in the DSM-1 addiction was seen as a product of aberrances in personality, in the DSM-II the wording changed to dependence while focusing more on psychological constructs (e.g., ‘evidence of habitual use, or a clear sense of need for the drug’).
  • By the DSM-III, a distinction was made between substance dependence and substance abuse, with the former characterized by physiological dependence (e.g., tolerance and withdrawal) and again rooted in the framework that it is a psychological disorder rather than a problem of personality or the mind.
  • In the DSM-IV, factors contributing to addiction were identified as including not only psychophysiology (tolerance and withdrawal), but also cognition — a definition that would carry over to future editions of the DSM (V and VI).
  • By the DSM-V, we see a much more holistic definition of substance dependence, emphasizing the psychological changes that occur from drug abuse which promote a lack of cognitive control over the use of the drug.

With the continuous development of advanced research techniques, various approaches have been applied to the field, and these have produced comprehensive insights into the processes underlying drug addiction. Via neuroimaging technology, experts have observed that chronic drug exposure causes stable changes in the brain at the molecular and cellular level, and that these changes may perhaps underlie behavioral abnormalities.

Gene knockout technology and genomic scanning enable us to identify both genes that contribute to individual risk for addiction and those through which drugs may cause addiction. Based on this empirical evidence, experts tend to consider drug addiction as a kind of brain disease.

While early use of a drug may indeed be by choice, the neurobiological changes that occur with continued use, particularly to the prefrontal cortex among other regions related with executive function, compromise inhibitory control which when coupled with physiological and psychological craving for the drug lead to uncontrolled drug use. Thus, it is the mechanisms that occur as a result of taking the drug that make uncontrolled substance use a disorder.

Numerous drugs/substances can promote addiction. Thus far, scientists have identified the most common classes of addictive drugs/substances. According to the fifth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) and the Tenth Revision of the International Classification of Diseases and Related Health Problems (ICD-10), the most common addictive drugs are:

  • alcohol;
  • caffeine;
  • cannabis;
  • hallucinogens;
  • inhalants;
  • opioids;
  • sedatives, hypnotics and anxiolytics;
  • cocaine;
  • tobacco and other (or unknown) substances.

In addition to these common drugs, DSM-V also list anxiolytics, amphetamine-type substances and inhalants, while ICD-10 has volatile solvents on its list.

In the DSM-V, drug addiction is presented in the substance use disorders section, which describes a cluster of cognitive, behavioral, and physiological symptoms indicating that the individual continues using the substance despite significant substance-related problems.

The detailed descriptions of these diagnostic criteria offer us a specific understanding of drug addiction. Generally, most drugs can fulfill 11 different diagnostic criteria terms, for the exception of caffeine.

Similarly, in ICD-10, the ‘Dependence Syndrome’ section also describes a cluster of physiological, behavioral, and cognitive phenomena in which the use of a substance or a class of substances, mainly fulfills 6 terms. In contrast to the DSM-V however, the ICD-10 considers the desire (often strong, sometimes overpowering) to take psychoatice drugs as the central descriptive characteristic of a dependence syndrome.

Dependence versus Addiction

The World Health OrganizationOpens in new window and the American Psychiatric AssociationOpens in new window once used the term “substance dependence” or “drug abuse”, rather than “drug addiction”, until the DSM-V was published.

Drug dependence is a state of psychic or physical dependence, or both, on a drug, arsing in a person following the administration of that drug on a periodic or continuous basis.

The transition from DSM-IV to DSM-V saw the preference for the word ‘dependence’ as a euphemism for addiction, reportedly as an attempt to help destigmatize addicted patients. This however, resulted in confusion amongst clinicians, where ‘dependence’ in a DSM-sense was really ‘addiction’, yet dependence was known as the normal physiological adaptation to the repeated use of a drug or medication.

Thus, it is important to highlight that pharmacological dependence is characterized by tolerance and/or withdrawal symptoms that arise from the continued exposure of the central nervous system to a drug. This is distinct from addiction, which is characterized by compulsive drug-seeking behavior.

How to Diagnose Substahnce Addiction?

Overall, drug addiction, or substance use disorder, may be diagnosed after thorough evaluation by a clinical psychologist, a psychiatrist, or licensed alcohol and drug counselor ( Current criteria for diagnosis are included in the Diagnostic and Statistical Manual of Mental Disorders (DSM-V). These include:

  1. Taking larger amounts or over a longer period than intended;
  2. A persistent desire or unsuccessful effort to cut down or control the use of the drug/substance;
  3. A great deal of time is spent in activities necessary to obtain and use drug/substance or recover from its effects;
  4. Craving, or a strong desire or urge to use the drug/substance;
  5. Recurrent use resulting in a failure to fulfill major role obligations at work, school, or home;
  6. Continued use despite having persistent or recurrent social or interpersonal problems caused or exacerbated by the effects of drugs;
  7. Important social, occupational, or recreational activities are given up or reduced because of drugs/substance use;
  8. Recurrent use in situations in which it is physically hazardous;
  9. Drug/substance use is continued despite knowledge of having a persistent or recurrent physical or psychological problem that is likely to have been caused or exacerbated by the drug;
  10. Tolerance, as defined by either of the following: (a) a need for markedly increased amounts of drug/substance to achieve intoxication or desired effect, (b) a markedly diminished effect with continued use of the same amount of drug/substance;
  11. Withdrawal, as manifested by either of the following: (a) the characteristic withdrawal syndrome for drug/substance, (b) drug/substance is taken to relieve or avoid withdrawal symptoms.

These 11 criterion can be sorted into subgroupings of impaired control over substance (criterion 1 – 4), social impairment (criterion 5 – 7), risky use (criterion 8 – 9), and pharmacological criteria (criterion 10 – 11). However, it is necessary to note that different drug types fulfill different sets of criteria for withdrawal, and thus specific diagnoses should refer to drug-specific criteria sets of withdrawal.

The severity of substance use disorder can be from mild to severe, based on the number of symptom criteria endorsed. A mild substance use disorder can be referred by the presence of two to three symptoms, moderate by four to five symptoms, and severe by six or more symptoms within a 12-month period.

In ICD-10, a definite diagnosis of drug dependence should usually be made only if three or more of the following have been present together at some time during the previous year:

  1. a strong desire or sense of compulsion to take the substance;
  2. difficulties in controlling substance-taking behavior in terms of its onset, termination, or levels of use;
  3. a physiological withdrawal state when substance use has ceased or been reduced, as evidenced by: the characteristic withdrawal syndrome for the substance; or use of the same (or a closely related) substance with the intention of relieving or avoiding withdrawal symptoms;
  4. evidence of tolerance, such that increased doses of the psychoactive substance are required in order to achieve effects originally produced by lower doses (clear examples of this are found in alcohol- and opiate-dependent individuals who may take daily doses sufficient to incapacitate or kill non-tolerant users);
  5. progressive neglect of alternative pleasures or interests because of psychoactive substance use, increased amount of time necessary to obtain or take the substance or to recover from its effects;
  6. persisting with substance use despite clear evidence of overtly harmful consequences, such as harm to the liver through excessive drinking, depressive mood states consequent to periods of heavy substance use, or drug-related impairment of cognitive functioning; efforts should be made to determine that the user was actually, or could be expected to be, aware of the nature and extent of the harm.
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