Drugs are addictive substances that can generate a great dependency in the person who uses them.

In this article we will make a brief description of what drugs are, and then go into how one type of them works: stimulant drugs. Specifically, we will talk about the two most frequent stimulant drugs : cocaine and amphetamines. We will analyse their most outstanding characteristics, their mechanism of action, the disorders associated with them and what effects they produce in our organism.

What are drugs?

Drugs are substances that, when introduced into the body, act on the central nervous system (CNS), altering or modifying its functioning.

These are substances that can easily cause different psychological disorders, such as substance use disorder (where the use of the drug is excessive, interfering with the person’s normal functioning) and two types of substance-induced disorders; intoxication and withdrawal (withdrawal syndrome).

But… what kinds of drugs are there? In the DSM-5 (Diagnostic Manual of Mental Disorders), we find the following classification of drugs :

  • Alcohol
  • Caffeine
  • Hallucinogens (phencyclidine and others)
  • Caffeine
  • Cannabis
  • Inhalants
  • Opiates
  • Sedatives/hypnotics/anxiolytics
  • Stimulants (cocaine, amphetamines and others)
  • Tobacco
  • Other substances

That is, according to the manual, we find up to 10 different types of drugs, depending on their characteristics and effects.

As we can see, among the stimulant drugs we find: cocaine, amphetamines and others. That is why in this article we will talk about cocaine and amphetamines, because they are the most common stimulant drugs.

Stimulant drugs

Stimulant drugs are a type of drug that, as their name suggests, stimulate the activity of the central nervous system (CNS); that is, they are excitatory drugs that intensify brain activity.

On the other hand, among the effects of stimulant drugs we find a greater acuity of mind, as well as increased energy and attention, along with an increase in blood pressure and speed of breathing and heart.

In terms of their mechanism of action, stimulant drugs increase the levels of three types of brain neurotransmitters: dopamine, serotonin and noradrenaline (all monoamines).

Now, let’s talk about the stimulant drugs mentioned:

1. Cocaine

Cocaine is one of the stimulant drugs that exist. Thus, it is a drug that excites or stimulates the central nervous system (CNS), through a mechanism of action that consists of increasing the levels of dopamine, serotonin and noradrenaline in the brain . Specifically, what cocaine does is block the neuronal reuptake of these three brain neurotransmitters.

This drug produces a series of important psychological and behavioural changes, which are manifested through three phases: the up phase (with symptoms such as euphoria, overflowing energy…), the down phase (depressive symptoms) and the hangover phase.

1.1. Route of consumption

Cocaine can be consumed in different ways, i.e. it has different consumption routes. The most common are: intravenous, smoked or snorted . In the first two cases, its progression through the body is faster; in the third case (snorted), its progression is more gradual.

1.2. Consumption pattern

The pattern of consumption associated with cocaine logically varies from person to person. The episodic pattern involves a separate use of cocaine, of two or more days, with “binges” in between. The daily pattern, on the other hand, involves a progressive increase in the use of the substance.

1.3. Prevalence

According to the DSM-5, about 0.3% of subjects over 18 years old present a cocaine use disorder , with the age range of highest use being 18-29 years. On the other hand, a greater consumption of this stimulant drug was observed in men (0.4%), compared with consumption in women (0.1%).

1.4. Cocaine abstinence syndrome

Withdrawal syndromes associated with different stimulant drugs produce a series of symptoms that can cause great discomfort in the person who suffers from it. In the case of cocaine (being a stimulant drug), the symptoms that appear in such a syndrome are opposite: that is, essentially depressive symptoms will appear.

Specifically, in cocaine withdrawal, a three-phase pattern , consisting of three phases, is produced. In the first phase (crash phase), acute dysphoria appears, with a descent into a depressed mood, along with anxiety. Other associated symptoms also appear, such as: agitation, fatigue, exhaustion, hypersomnolence, anorexia, etc.

In the second phase, abstinence itself takes place, with a reduction of the previous dysphoric symptoms . In this phase, subjects respond with more abstinence to conditioned environmental stimuli (such as places where the subject usually consumes the drug).

Finally, in the third and last phase of the cocaine abstinence syndrome, a state of excitement is produced in the subject ; its duration is indefinite, and in it an irresistible intermittent desire appears, associated with multiple conditioned stimuli, such as: moods, places, people, white powder, mirrors, etc.

2. Amphetamines

Another stimulant drug we can find is amphetamines. Amphetamines, just like cocaine, are compounds with strengthening and stimulating effects for the brain and the body .

Along with cocaine and other substances, amphetamines are included in DSM-5 in the group of stimulant drugs. On the other hand, the ICD-10 (International Classification of Diseases), includes them in the group of “other stimulants”, next to caffeine.

Regarding their mechanism of action, amphetamines act mainly by inducing the release of monoamines (i.e. serotonin, noradrenaline and dopamine, three types of neurotransmitters in the brain). In other words, like cocaine, amphetamines act on these same three neurotransmitters, although in different ways.

Compared to cocaine, these stimulant drugs have a longer lasting effect on the body, which is why they need to be administered less frequently.

2.1. Prevalence

The prevalence of amphetamine use disorder is slightly lower than that of cocaine, at around 0.2 per cent according to the DSM-5 in subjects over 18 years of age .

In addition, subjects diagnosed with amphetamine use disorder are mostly in the 18-29 age group (0.4 per cent), with male use being more prevalent (vs. female).

2.2. Associated disorders

As with the other stimulant drug, cocaine, amphetamines can lead to different disorders . We can talk about two large groups of disorders: disorders induced by the use of the substance (consumption disorder), and disorders induced by the substance itself (intoxication and abstinence).

Thus, amphetamines (and/or their use) can produce all these disorders.

Bibliographic references:

  • American Psychiatric Association (APA) (2014). DSM-5. Diagnostic and statistical manual of mental disorders. Madrid: Panamericana.
  • WHO (2000). ICD-10. International Classification of Diseases, Tenth Edition. Madrid. Pan-American.
  • Stahl, S.M. (2002). Essential Psychopharmacology. Neuroscientific bases and clinical applications. Barcelona: Ariel.