Drugs are substances that alter the functioning of the central nervous system and cause changes in behavior, the body, and the mind. They can even cause mental disorders. In this article, we ask the question, how many mental disorders due to substance abuse are there? Furthermore, what characterizes them?

When the disorder doesn’t abate with the abandonment of the substance in question, we speak of a primary mental disorder. On the other hand, if it does subside with the abandonment of the substance, we speak of mental disorders due to substance use.

However, it’s useful to differentiate a disorder that originates from the consumption of the substance itself (substance-use- disorders) from the disorders that the drugs themselves subsequently provoke (substance-induced- disorders). These include withdrawal, intoxication, and other mental disorders such as depression or obsessive-compulsive disorder.

Substance use disorder

This is the disorder caused by the use of the drug itself. According to the DSM-5 (APA, 2013), it’s a maladaptive pattern of behaviors related to the use of the substance. It’s expressed with two or more of the following symptoms for at least 12 months:

• Taking the substance in larger amounts or for longer than desired. 
• Wanting to cut down or stop using the substance but being unable to.
• Spending a lot of time obtaining, using, or recovering from substance use.
• Feeling intense cravings to use the substance.
• Not meeting obligations due to its consumption.
• Continuing to use it even if it causes social problems.
• Reducing important social, work, or recreational activities because of using the substance.
• Using the substance in dangerous situations, causing physical or mental harm
• Continuing to take the substance despite the physical and psychological danger
• Tolerance. Needing more of the substance to get the desired effect.
• Withdrawal. The symptoms that occur as the use of the substance decreases.

Substance-induced disorders

In the group of substance-induced disorders we find the following:

Intoxication

These disorders are directly related to the acute pharmacological effects of each substance and improve with time. In fact, there’s often complete recovery except when tissues are damaged or complications arise.

Different types must be specified: uncomplicated intoxication with trauma or bodily injury, with another complication of a medical nature, with delirium, with perceptual distortions, with coma, with seizures, or pathological intoxication.

However, what exactly is substance use toxication? According to the DSM-5, it’s a ‘specific reversible syndrome of a substance due to its ingestion (or its exposure)’. Maladaptive behavioral or psychological changes appear, and the symptoms aren’t due to a general medical condition or better explained by a mental disorder.

Withdrawal

Withdrawal is a specific syndrome due to the cessation or reduction of long-term and large-scale use of a substance. It’s a disorder that causes great discomfort.

On many occasions, the syndrome occurs in the opposite direction to the symptoms produced by the intoxication of the same substance. For example, if it’s alcohol, which is a depressant, abstinence of the same causes the opposite effect. In other words, symptoms of agitation and anxiety.

Substance-induced mental disorders

Substance-induced mental disorders, cause a variety of symptoms that are characteristic of other mental disorders. The DSM-5 specifies the following:

1. Delirium

Delirium, or acute confusional syndrome, is a disorder of the higher mental functions. It develops in a short period of time and is characterized by an alteration of the state of consciousness (modifications of alertness) and by a series of cognitive disturbances.

Among them, are disorientation, delusions, and hallucinations. Drugs (and medications) can cause a confusional syndrome, either through intoxication or withdrawal.

2. Neurocognitive disorders

Neurocognitive disorders can also be caused by drugs. They involve a moderate or significant cognitive decline with respect to the previous level of performance in one or more cognitive domains. For example, attention, executive functioning, learning and memory, language, perceptual-motor area, and social cognition

3. Psychotic disorder

Psychotic disorder is one that arises during or immediately after consumption and isn’t explained by acute intoxication. It’s also not part of the substance withdrawal syndrome. It involves a loss of contact with reality and perceptual disturbances. These include hallucinations, or thought disturbances, such as delusions.

4. Mood disorder

Depression or bipolar disorder can also be drug-induced. However, these disorders, and, in general, the mental disorders due to substance use cease when the person stops using the drug or when they pass the withdrawal phase.

5. Anxiety disorders

Drugs can also cause anxiety. Among these disorders are generalized anxiety disorder (GAD) and specific phobias.

6. Sexual disorders

Drugs also trigger alterations in the sexual area. For example, erection disorder in men or hypoactive sexual desire in women.

7. Sleep disorders

Sleep disorders that can be caused by drugs include insomnia, hypersomnia, and restless legs syndrome.

8. Hallucinogen-persisting perceptual disorder

Hallucinogen persisting perceptual disorder (HPPD), is a condition characterized by the continuous presence of visual disturbances or flashbacks. These are similar to those experienced during the use of hallucinogenic drugs.

9. Obsessive-compulsive disorder

Obsessive-compulsive disorders (OCD) that can arise due to substance use or withdrawal include different subtypes of OCD (for example, cleaning OCD, checking OCD), body dysmorphic disorder, or hoarding disorder, among others.

Drug-induced mental disorders vs. primary mental disorders

According to the  DSM-5, it’s necessary to wait four weeks after intoxication or withdrawal from the substance before a diagnosis of one of the mental disorders due to substance use can be made. In this way, if symptoms subside, a diagnosis of substance-induced disorder could be made; if not, it would be a primary mental disorder.

This is what allows us to distinguish whether it’s the substance (or its withdrawal) that has caused the disorder or not. If not, it would be a primary mental disorder, which already existed or would exist independently of the substance abuse.

As we can see, drugs can really interfere with both physical and mental health. Not only because of their use per se but also because of the later effects due to their continued and prolonged use over time. In these cases, it’s always best to ask for professional help.

Drug Use, Abuse, and Addiction