Signs and Symptoms of Addiction

Addiction can reveal itself in physical signs, as well as psychological and behavioral ones, although they are not diagnostically specific for the condition. Substance users may have dilated pupils or glazed eyes, slurred speech, and ramble when they talk. They can show changes in movement patterns—depending on the type of substance involved, psychomotor retardation (heroin) or jumpiness (cocaine). Substances users often become so preoccupied with getting and using that they forego eating and suddenly lose weight. Another sign of addiction is a shift in sleep and wake patterns—sleeping too much or too little, or at unusual times.

Addiction involves a great many contradictions, including behavioral choices in spite of oneself. One of the most puzzling aspects of addiction is the way it prompts people to violate their own codes of behavior, their own sense of self. Neuroscience sheds light on the phenomenon: Studies show that as the drive for the drug and its reward becomes increasingly inscribed in brain circuity, there are corresponding changes in circuity weakening the person’s powers of judgment and control. People who are addicted often act in ways that even they do not endorse—lying, stealing, socially withdrawing, becoming suspicious—and even the conscientious can become neglectful of obligations.

Those who become addicted are usually acutely aware of their own behavioral shifts and especially how they are disappointing others, even as they rationalize away their behavioral anomalies. Recovery often requires addressing the guilt and shame people feel over their own addictive behavior. Left unaddressed, such painful negative self-related feelings can seek quick relief in drug use before impulse control is regained.

Addiction involves both the mind and the body—and every other facet of existence, because they all interact. There is no real distinction between physical addiction and psychological addiction. Substances of abuse affect the reward system of the brain, mediated by the neurotransmitter dopamine. Substance-induced physical changes to the part of the brain that responds to dopamine (nucleus accumbens, or striatum) progressively power the motivation to seek the drug again and again, and, at the same time, lower the capacity for self-control. The physical changes to the pleasure-experiencing centers of the brain induce physical changes to the prefrontal cortex, weakening the capacity for decision-making and impulse control.

Substance use becomes an addiction when a person can no longer control the use, when they want to cut back but can’t manage to, and when use begins to interfere with functioning—affecting work, school, relationships, and sense of self. That point differs from one person to the next, due to many biological and situational variables influencing response to a substance. Addiction is an individual response to repeated use of a substance (or activity) that triggers an outsize activation of the brain’s reward center, but just as not everyone who uses a substance becomes addicted, addiction does not hinge on any specific amount of drug consumed.

While the best-known signs of addiction may be physical changes in a person—weight loss to the point of emaciation, the red face of problem drinkers—those occur late in the course of substance use. The early signs of addictive problems are behavioral. Experts identify at least five early warning signs of addiction.

• rationalization: justifying use because of a “real need” the substance is serving, whether it is aiding social experience or fostering sleep.

• personality changes: unpredictable displays of hostility, suspicion, or irritability, or rapid mood swings

• relationship shifts: wearing out longstanding relationships, rapidly turning to new sets of friends

• deteriorating work performance: increasing difficulties concentrating on work showing up in simple mistakes and, often, new difficulties with coworkers

• emergence of a “shadow self”: violating deep values as drug use affects the prefrontal cortex of the brain.

You look forward to getting high. You devote increasing amounts of time planning to get drugs or worrying about where your next dose is coming from. You find yourself rummaging through other people’s medicine cabinets in search of drugs.

Your involvement with drugs begins to have negative consequences. It interferes with your functioning—you start missing obligations and events. You make excuses for yourself—to yourself and to others, about why you need the substance, about not showing up, about making mistakes at work, about how tomorrow will be different. You break promises to yourself that you will stop using—a source of self-contempt that has a way of perpetuating addiction by needing relief in the high of substance use. You drift away from longtime friends. You get secretive about your activities. You get defensive or belligerent with loved ones or colleagues who want to know what’s going on; they notice peculiarities about your behavior or appearance that you are not likely to recognize. You maintain a belief that you can stop any time you want—despite evidence to the contrary.

Addiction and substance use disorder are two terms for the same condition. The DSM adopted the term Substance Use Disorder in 2015, when it published its fifth edition. As the manual explains: “Note that the word addiction is not applied as a diagnostic term in this classification, although it is in common usage in many countries to describe severe problems related to compulsive and habitual use of substances. The more neutral term substance use disorder is used to describe the wide range of the disorder, from a mild form to a severe state of chron­ically relapsing, compulsive drug taking. Some clinicians will choose to use the word ad­diction to describe more extreme presentations, but the word is omitted from the official DSM-5 substance use disorder diagnostic terminology because of its uncertain definition and its potentially negative connotation.”

Psychological dependence is a term sometimes used to indicate the mental processes of addiction, but it has no real meaning given current understanding of the way the brain works. There is no real difference between physical addiction and psychological addiction. Addiction is one of those conditions that demonstrates it is not possible to distinguish between physical and psychological aspects of behavior.

Nevertheless, some people erroneously believe that processes such as withdrawal are distinctly physical while other feature of addiction, such as drug cravings or the inability to stop using a substance, are purely psychological. In fact, inability to regulate use results from a physiological process—progressive weakening of the neural circuitry in the brain’s executive control center in response to repeated use of a dopamine-activating substance. Cravings, or deep desire for a substance, arise from alterations in reactivity patterns of nerves in the brain’s reward center.

Confusion arises in part because of historical misunderstanding: It was once thought that withdrawal was the defining feature of addiction and every other aspect of addiction did not reflect physical processes. It is now known that withdrawal symptoms are not an invariable feature of addiction—they do not occur with addiction to hallucinogens, for example—and that all facets of addiction reflect physical changes in brain circuitry, and those changes are reversible after substance use stops.

Cravings are intense desires for a substance and motivate the repeated seeking of the substance and its effects. They are typically viewed as a sign of entrenchment of the addiction process. Cravings intrude on thought processes, create considerable distress, and focus attention on immediately satisfying the desire for the substance. Cravings can be seen in brain imaging studies as areas of heightened activity in the reward center of the brain in response to specific environmental signals that have been connected to drug use through experience.

Cravings occur when the brain remembers drug use. They can be set in motion by past memories or current environmental cues relating to substance use and are thought to be a force behind relapse, although they are not a clinically consistent predictor of relapse. Any cue with emotional significance registers on the brain's amygdala, which then activates the nucleus accumbens and its dopamine neurons. Their activation gives rise to the sense of motivation,  experienced as a highly focused urge to seek the substance.

There is no objective measure of the strength of cravings, but they are highly dynamic and fluctuate, varying in intensity and duration in any individual throughout the course of a day. They naturally rise and fall over several minutes, and many treatments for addiction train people in techniques for outsmarting cravings or distracting themselves from drug cravings until they lessen in intensity.

Withdrawal symptoms occur when drug use is abruptly stopped or the dosage is sharply diminished. They occur because the brain is an adaptive organ (which permits learning of all kinds), and in response to the repeated presence of a psychoactive substance, the brain undergoes changes in neurotransmitter activity and receptor sensitivity in various systems. When use of that substance stops abruptly, cessation disrupts all the adaptations to that substance the brain has made; over time, it will adapt to absence of the drug—but that process takes time.

The clinical manifestation of abrupt cessation of a substance of abuse is withdrawal. Symptoms of withdrawal range from sweatiness, shakiness, tremors, and seizures to upset stomach, diarrhea, and vomiting. Irritability, agitation, restlessness, and sleep disruption are common withdrawal symptoms for many drugs as are muscle cramps, headaches, and changes in blood pressure and heart rate. Drug cravings can be fierce, and fear of withdrawal symptoms often drives continued drug use.

Withdrawal symptoms do not occur with all substances; for example, stopping hallucinogens or marijuana does not typically lead to withdrawal symptoms. Further, the intensity of withdrawal depends on the amount of drug usually taken and the duration of its effects. Withdrawal from such drugs as heroin, painkillers, alcohol, and benzodiazepine tranquilizers can be life-threatening, and medical supervision is generally advised.

The severity of addiction is only partially related to the amount of substance a person uses. The difference between mild and severe addiction is the number of the 11 DSM addiction criteria a person meets. The criteria relate to ability to control use, the negative impact use has on self and life, and the existence of physiological dependence. Substance abuse disorder is considered mild in the presence of two or three criteria. It is considered moderate in the presence of four or five signs. In the presence of six or more symptoms, substance use disorder is considered severe. In fact, sometimes the word addiction is reserved for the most severe cases. Because repeated use of a psychoactive substance often creates the motivation for further use, substance abuse is seen as a self-perpetuating disorder and considered to have a high potential for progression.

A widely used clinical tool is the Addiction Severity Index, which provides a broad view of problems related to substance use. It is a 200-question semi-structured interview that elicits information about problems in seven distinct areas often negatively affected by substance use—medical status, employment and support, frequency of drug use, frequency of alcohol use, legal issues, family/social status, and mental health status. Problems are rated on a scale of 1 to 5 by domain, reflecting how bothered a person is by problems of that type. The ASI is typically used in gauging the type and intensity of treatment a person might need and as a measure of the success of treatment.

Addiction hinges on many factors, only some of which have to do with the properties of a drug. It is possible to get addicted to a psychoactive substance that produces a pleasurable effect, but by no means do the majority of people who consume such substances get addicted. For example, many people are medically treated with opioid painkillers for a period of time and easily discontinue medication when pain remits. Likewise, alcohol is consumed widely around the world with meals and in social situations without resulting in addiction.

One of the most important factors influencing attractiveness of regular substance abuse is the existence of significant opportunities for establishing goals and experiencing meaningful rewards in life. Under such circumstances, drugs can hold little allure. Research demonstrates, for example, that poverty is a strong contributor to drug use, because it imposes many barriers to resources and impediments to achieving individual goals. Similarly, unemployment is a significant independent risk factor for substance use and for relapse after treatment. Researchers have long observed that alcohol use increases during recessions.

Substances of abuse deliver an intense sensation that creates a neurochemically driven motivation to repeat the experience again and again. At the same time, the repeated use of a substance that delivers the intense (if short-lived) reward of a chemical high weakens the decision-making and impulse-control centers of the brain, making it difficult to resist cravings.

Many drug users have made many promises to themselves to stop—and broken them as well, leading them to believe they are incapable of stopping. Users, too, commonly experience negative life effects of addiction—whether to relationships, work, or in other domains, and the painful feelings of self-disappointment and shame trap them in negativity that further erodes hope and finds fast relief in the drug high.

In addition to the direct action of the consumed substance in producing a high, many circuits of brain function adapt their operations to the presence of the psychoactive agent, typically through increases or decreases in sensitivity of neurotransmitter receptors. When that substance is suddenly unavailable, that absence leaves many brain operations exposed and interferes with the various functions. One of the first symptoms to occur is general shakiness.

Wet brain is the colloquial term for the nutritional brain bomb of severe thiamine deficiency that occurs with chronic abuse of alcohol. It is medically known as Wernicke’s Encephalopathy or Wernicke-Korsakoff Syndrome. It arises when people get a large proportion of their calories from alcohol, because the substance interferes with the intestinal absorption of thiamine, also known as vitamin B1. Thiamine is critical for energy production and serves as a cofactor in many enzymatic reactions regulating glucose utilization by mitochondria, the power factories inside all cells.

Because the brain uses a disproportionate amount of energy to power its many high-level functions, thiamine deficiency can lead to damage to the mitochondria of nerve cells. The clinical manifestation of wet brain syndrome are memory loss and confusion, difficulties in muscle coordination when standing or walking—sufferers have a distinctive shuffling gate known as ataxia—and abnormal eye movements and visual changes such as double vision resulting from paralysis of eye muscles. These signs, similar to those of intoxication, exist in the absence of drinking.

Recovery is possible in the early stages, when infusions of the vitamin can restore thiamine reserves. But if thiamine deficiency is left untreated, neurological damage can become irreversible, and people experience a form of dementia. It is marked by hallucinations and other signs of psychosis, difficulties with memory, and confabulation, attempts to make up stories to cover gaps in memory. It is estimated that 80 percent of long-term heavy drinkers suffer from some degree of thiamine deficiency.