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Substance-Use Disorders

What is a substance? What is substance use and how is it different from substance misuse? How are substance abuse and dependence different? These and many such questions grapple the masses with the increasing percentage of addiction, its economic and social costs and the disorders that tag along with addiction.

A substance refers to those chemical compounds that are ingested into the body to alter the mood and behaviour of the individual and has severe health and social hazards. These substances include psychoactive chemicals that alter the mood, behaviour or both. These are not just known yet illegal drugs like cocaine but also substances like alcohol, tobacco (nicotine), caffeine etc. Substance use is the consumption of these legal or illegal psychoactive substances in moderate quantities which alters the mood, behaviour and functioning of the individual in their social, educational or occupational life. Drinking a cup of coffee, smoking an occasional cigarette, having a beer with friends are all classified under substance use. Intoxication on the other hand is the consequence of the consumption of considerable quantities of these psychoactive substances that leads to one being drunk or high. Intoxication is seen by those around that individual as impaired judgement, shifts in mood, slurring of words, impaired motor ability etc.

Defining substance “abuse” is challenging as it is difficult to point out how much substance is too much substance. Is drinking three glasses of wine in an hour, substance abuse? Or five? Consumption of what quantity of cannabis classified abuse of the drug? Diagnostic and statistical manual -5 defines substance abuse based on how significantly it affects the individual’s life. If the substance is causing significant problems in an individual’s social, occupational and educational life, hampers their interpersonal relations with others and puts that individual in physically dangerous situations, it can be classified as abuse of that substance. “Substance dependence” is the medical term used to describe the abuse of drugs or alcohol which leads to significant disruption in the life of that individual. Substance-Dependence is commonly known as addiction. There is a disagreement between experts about the definition of addiction and whether it can be used interchangeably with substance dependence. Some signs of drug dependence can be:

  • An increasingly greater requirement of the consumption of the drug to feel the effects (tolerance)

  • A negative physical reaction in the absence of the drug (withdrawal)

  • Drug-seeking behaviour i.e repeated use if the drug or a desperate need to ingest the drug

  • Withdrawal from social and leisure activities

  • Continued usage of drugs despite the knowledge of its effects on oneself and those around them

Diagnosis of a substance-related disorder can be difficult. Interestingly, if an individual is substance-dependent that does not mean that they are abusing that substance. For instance, a cancer patient is dependent on their medication containing morphine to reduce the pain that results from the treatment and may even build a tolerance against it but yet not abuse the drug. The DSM-5 has prescribed 11 symptoms of substance use disorders that range from mild to more severe abuse.

The majority of the individuals suffering from substance abuse have a comorbid mental illness like major depressive disorder or anxiety disorder etc. Another issue with diagnosis is that if an individual has a comorbid physical or mental condition, then the question arises of whether the individual is consuming the drug to combat that condition or consuming it in excess as an escape mechanism? Common examples of why this question is raised can be if an individual is suffering from depression, anxiety, post-traumatic stress disorder and are consuming drugs. This is why the DSM has tried to identify whether a particular symptom is the cause of an underlying condition or the substance. If a symptom seen in schizophrenia, anxiety or any related conditions are seen within the period of 6 weeks after withdrawal from a drug, the individual is not given a diagnosis of a separate mental illness. Some of the commonly used substances can have severe effects on our body leading to addiction and withdrawal. Withdrawal from these substances can lead to anxiety, depression, schizophrenia etc.

Substances and related disorders can be broadly grouped into 6 categories:

1. Depressants and Related Disorders

These substances lead to a sedation-like state and can cause relaxation. They can reduce the activity of the central nervous system and are consumed with a view to relax oneself. These types of substances include alcohol, barbiturates (Seconal, etc), benzodiazepines (Xanax, Valium etc). These substances are among the most likely to produce dependence, tolerance and withdrawal. The most commonly used substance and resulting disorder is alcohol-related disorder. Alcohol has been consumed in various forms since ancient times. Alcohol initially induces stimulation which is because it affects the inhibitory centres of the brain and makes us more out-going, carefree, etc. It impairs our motor functioning, increases confusion, reduces judgement, reaction time, vision and even hearing.

Alcohol affects many of our body parts including the brain, the oesophagus, the small intestine, lungs etc. it influences our neuroreceptors especially the GABA system, which is responsible for inhibitory activities. The blackouts, memory loss that happens when one is drunk may result from the interaction of alcohol with the glutamate system. This neurotransmitter affects our sleep, mood and eating behaviour and is hence held responsible for alcohol cravings. Chronic alcohol usage can have severe effects on our body including tremors, nausea, vomiting, anxiety, insomnia, hallucinations and a condition known as withdrawal-delirium. This condition can cause one to experience severe hallucinations and body tremors. Some may experience seizures, memory impairment, dementia and Wernicke-Korsakoff syndrome. Dementia is a broad spectrum of neurocognitive disorder which leads to memory loss, impaired judgement, reasoning, communication etc. Wernicke-Korsakoff syndrome results in confusion, loss of muscle coordination, intelligible speech. Dementia caused by alcohol has irreversible effects on the brain even if the substance use has reduced or stopped. Fetal Alcohol Syndrome (FAS) is a combination that can occur in a child whose mother drank during her pregnancy. FAS is characterized by cognitive impairments, behavioural problems, learning disabilities etc. Children with FAS tend to have distinct facial features and may also have growth retardation. About 20% of individuals with alcohol dependency are able to stop drinking spontaneously and do not relapse. It is often also believed that alcohol intoxication can lead to increased violence. Research has found that alcohol does not cause aggression in an individual bit is likely to increase impulsivity and impair the ability to judge the consequences of their actions.

Another category of depressants includes sedative (calming), hypnotic (sleep-inducing), and anxiolytic (reducing anxiety) drugs like barbiturates (Amytal, Seconal, Nembutal etc) i.e sedatives, benzodiazepines (Xanax, Valium, Ativan etc) i.e anxiety-reducing drugs. In small proportions it can be used to relax the muscles and can produce a mild feeling of well-being. Larger dosages can be harmful where it would lead to slurred speech, problems with walking, attention etc. It can even lead to death and is the common means to suicides. These drugs are used to induce sleep and calm an individual down. But in larger dosages, it can cause aggression, maladaptive behavioural changes, impaired judgement, impaired social or occupational functioning, impaired motor functioning.

2. Stimulants and Related Disorders

These substances lead one to be active and alert and can elevate mood. Stimulants include amphetamines, cocaine, nicotine and caffeine. Amphetamines are those drugs which in strong dosages help one feel elated and energetic. After a period of feeling high, eventually one feels like they are crashing. Amphetamines are prescribed to people who suffer from narcolepsy, ADHD etc. Intoxication in amphetamine use disorder includes behavioural symptoms like euphoria, lack of emotional expression, reduced sociability, anxiety, tension, muscle weakness, panic, agitation, seizures etc. Amphetamine tolerance builds very quickly which is even more dangerous. Amphetamine called methylenedioxymethamphetamine (MDMA) commonly known as “Ecstacy” is responsible for many people being hospitalized due to intoxication, overdose or has even caused death. Crystal meth i.e methamphetamine causes marked aggression and stays for a long time inside the body. Amphetamines stimulate the Central Nervous system and enhance the activity of dopamine and norepinephrine. Thus, due to the heightened level of these two neurotransmitters, amphetamine intoxication can cause hallucinations and delusions.

Cocaine is another stimulant that is heavily used by many individuals globally. It is extracted from the leaves of a plant called coca and has been heavily abused since ancient times. It is consumed in multiple forms including smoking, inhalants, leaf cigarettes etc. and since the 1970s, the usage of cocaine has been on a rise. Similar to the effects of amphetamines, the usage of cocaine in small amounts helps to increase alertness and increases blood pressure, pulse rate and causes a euphoria like feeling ultimately reducing sleep. A common experience of individuals who consume large amounts of cocaine is paranoia, known as cocaine-induced paranoia. This paranoia is a symptom of cocaine use disorder. Pregnant women who consume cocaine have found to have children who are more irritable than other children. Such babies may have poor birth-weight, a higher risk of behavioural problems and smaller head circumference.

Tobacco and caffeine-related disorders are also some of the most commonly found substance-related disorders. Tobacco intoxication or dependency tends to have more withdrawal symptoms like depression, increased appetite, insomnia, anxiety, weight gain etc. High consumption of nicotine can cause an increased risk of heart diseases, cancer convulsions, strokes etc. Caffeine is the most common psychoactive stimulant. It is known as the gentle stimulant as it is the least harmful amongst the other stimulants but can have harmful effects on a person’s body. Coffee, tea, energy drinks, cocoa products, all contain caffeine. Caffeine in small quantities can reduce fatigue and help one feel energetic but in high quantities, it can make one feel jittery, sleepless and restless. Many of us tend to feel unenergized and “groggy” without our morning coffee and this is usually because of the withdrawal from caffeine.

3. Opiates and Related Disorders

Opiate drugs or the drugs derived from opium poppy tend to have a narcotic effect on our body. It includes those family of drugs that are similar to the chemicals found in our brain and include drugs like heroin, oxycodone, methadone, morphine, codeine etc. These are typically used to reduce pain i.e produce temporary analgesia. Withdrawal from opium can be extremely severe and can lead to a person consuming them despite having the desire to stop. These symptoms typically arise within 6 to 12 hours of consuming the drugs and can include excessive yawning, nausea, vomiting, insomnia, diarrhoea, disruption in social and occupational life. Heroin is the most commonly abused opiate drug and has seen a staggering increase in its consumption. The brain has opioids like endorphins and enkephalins already present and opiate drugs excites this inherent opioid system.

4. Hallucinogen and Related Disorders

These substances tend to alter sensory perceptions of an individual and can produce symptoms like hallucination, delusions and paranoia. Marijuana and LSD are some of the most commonly abused drugs from this category of drugs.

Marijuana or Cannabis use started getting popularised in the 1960s and is still popularly used and abused by many. Marijuana is a product derived from dried parts of the hemp plant and is most commonly known as ‘weed’. Individuals consuming high quantities of marijuana can experience altered perception, mood swings, see vivid colours, hallucinations, paranoia and dizziness. Individuals who persistently consume marijuana may show cognitive impairments like memory loss, lack of concentration, poor social and academic involvement and negative employment outcome. The use of marijuana is a topic of controversy for many nations as there is evidence of the medical benefits of marijuana but also the fact that it can be extremely harmful to the individual. There are about 80 varieties of chemicals known as “cannabinoids” which are responsible for mood and behavioural changes. In some countries, the use of tetrahydrocannabinol (THC) is banned but they may permit the use of CBD i.e cannabidiol which is used for relaxation. Research has interestingly found that the neurochemical “anandamide” which is produced by the brain that resembles the euphoric feeling given by THC is derived from the Sanskrit word “Ananda” which stands for “bliss”. Marijuana usage has been popular across culture and ages. It is believed that the famous cartoon Scooby Doo mentions occasional “munchies” and the characters Shaggy was rumoured to be perpetually “stoned”.

LSD or d-lysergic acid diethylamide which is also referred to as “acid” is the most commonly used hallucinogen. It is responsible for multiple mental and physical problems like hallucinations, depersonalization, altered perception, blurred vision, sweating, increased heartbeat etc. Some other hallucinogens include psilocybin (present in some species of mushrooms), DMT (Dimethyltryptamine), PCP (Phencyclidine), Peyote (Mescaline) etc. Psilocybin is the drug often prescribed to individuals with ADHD. This drug is responsible for individuals having mystical experiences, mood changes, hallucinations etc. If taken in high quantities, hallucinogens lose their effectiveness but they typically have no withdrawal symptoms. The concern of experts with excessive usage is the psychotic reaction. Hallucinogens tend to interact with serotonin and norepinephrine and tend to hyperactivate these two neurotransmitters.

5. Other Drugs of Abuse

Some other psychoactive drugs that do not fall under any of the above categories include steroids, inhalants like airplane glue, anabolic steroids and prescription/ over-the-counter medication. Inhalants include substances like spray paints, paint thinners, laughing gas, nail paint remover, dry-cleaning fluid, markers and hair spray. These are some volatile solvents and hence are directly breathed into the lungs. They can cause anxiety, depression, impulsivity and fearlessness. They are easily absorbed into the bloodstream and their effects are similar to alcohol intoxication including slurring, dizziness, nausea, incoordination and euphoria. Some other drugs include dissociative anaesthetics which helps one to drowsiness, pain relief, depersonalization.

6. Gambling Disorder

Similar to the irresistible urge to consume drugs, individuals who have gambling disorder are unable to stop gambling and this causes negative effects for the individual.

The causes of substance abuse disorders are being researched for many years now. Genetic factors can be an important cause of substance abuse disorders. Comorbidity with other psychological disorders may also play an important part in why a person may abuse drugs. Environmental factors such as abuse, stress, separation may be some of the environmental causes of why someone may abuse a substance. Some individuals may be at a higher risk of substance abuse. Individuals with anxiety, ADHD, bipolar disorder, parents with a history of substance use, poor family environment, stress can be some of the risk factors.

Substance abuse treatment depends on the severity of the disorder. It involves multiple treatment plans and sometimes if an individual with severe substance use may even have to be admitted to a rehabilitation centre where a treatment plan is made for the individual to reduce the addiction. Sometimes, they are even prescribed medication to reduce the addiction, urge to consume drugs, reduce withdrawal symptoms. Support groups may also be helpful for individuals with substance dependence.


About 270 million between the age of 15 -64 have used substance and 35 million people are estimated to be suffering from a substance use disorder. It is estimated that about 0.5 million deaths annually are attributable to drug use with about 350 000 male and 150 000 female deaths (WHO). Substance abuse is rising by the day and has taken a serious route of destruction for many. Many organizations in India and across the world are working for the aid of individuals who are suffering from substance abuse. Substance abuse has a huge impact on the families of those suffering from substance abuse and can impact their social, occupational or educational lives. There is significant research being conducted about devising better treatment plans and helping those in need. Recovery is a very difficult process. Many people are unable to control the urge to drink or use a drug and relapse but many are able to do so. Regardless, the journey to complete recovery should not stop. As Confucius said, “It does not matter how slowly you go as long as you do not stop.”


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This article on 'Substance-Use Disorders' has been contributed by Smruti Pusalkar, who is a graduate Psychology student from Fergusson College. She is part of the Global Internship Research Program (GIRP), which is under the leadership and guidance of Anil Thomas. GIRP is an Umang Foundation Trust initiative to encourage young adults across our globe to showcase their research skills in psychology and to present it in creative content expression.

Smruti wishes to develop herself to be a more patient listener and a sharp observer to understand the happenings of the world and grow increasingly empathetic. She is passionate about mental health and well being and plans to pursue a career in this field. She is extremely curious about psychology and wants to spread awareness about mental health problems to help those in need.

Anil is an internationally certified NLP Master Practitioner and Gestalt Therapist. He has conducted NLP Training in Mumbai, and across 6 other countries. The NLP practitioner course is conducted twice every year. To get your NLP certification


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