Understanding Drug Abuse, Addiction, and Tolerance

Concept of Drug Abuse

Drug abuse refers to the modification of behavior that conditions continued drug use. There are two main types:

• Psychological Dependence: This is characterized by an obsessive concern with obtaining and consuming drugs. Individuals experience pleasure in using drugs and anguish at the thought of not being able to obtain them. This creates a habit of taking drugs that is perceived as necessary for their well-being.
• Physical Dependence: This involves measurable and reproducible physiological changes that occur due to chronic exposure to a drug. These changes become apparent when drug use is abruptly stopped.

Several variables influence the initiation and continuation of drug dependence:

• Substance-Related Factors: Availability, cost, purity, method of administration, speed of onset and termination of effects, and pharmacokinetics of the drug.
• Consumer-Related Factors: Genetic predisposition (innate tolerance), psychiatric symptoms, past experiences, expectations, and a proclivity for risky or prohibited behaviors.
• Environmental Factors: Social environment, community attitudes, employment status, education level, and the availability of other reinforcers.

Concept of Drug Addiction

Drug addiction is the propensity to consume drugs or substances for non-therapeutic purposes. Individuals seek states of euphoria, stupor, confusion, and isolation to evade reality and shift responsibility to the drug.

Valid criteria for defining addiction to drugs of abuse include:

• Using the drug more often or in greater amounts than intended.
• Unsuccessful attempts to quit using the drug.
• Experiencing intoxication at inappropriate times.
• Giving up other activities in favor of drug use.
• Continuing to use the drug despite knowing it is harmful.
• Developing a high tolerance to the drug.
• Experiencing characteristic withdrawal symptoms.
• Using the drug to avoid withdrawal symptoms.

Acute Intoxication

Acute intoxication is a transient state that follows the administration of a drug (either a single dose or repeated doses in a short time). It produces alterations in various physiological functions, psychological responses, and behaviors.

Concept of Tolerance

Tolerance is the reduction in response to a particular drug after repeated use. As tolerance develops, increasing amounts of the drug are needed to achieve the same effect. There are several types or factors contributing to tolerance:

• Pharmacokinetic Tolerance: Enzyme-inducing substances, after chronic use, are metabolized more rapidly. This results in a lower concentration of the drug reaching the target organ for the same dose. Chronic use leads to increased formation of enzymes that metabolize the drug.
• Pharmacodynamic Tolerance: This involves a mechanism where the target receptors in the body adjust, producing a reduced response to the same amount of the drug.
• Learned Tolerance: Individuals who chronically use a drug may learn to modify their behavior, appearing less intoxicated even when under the influence (especially in cases of mild or moderate intoxication). For example, a drunk person may learn to walk in a straight line despite being impaired.