Most Addictive Substances Can Cause Psychosis

Addiction is often described as a chronic brain disease. People with substance addictions compulsively ingest psychoactive substances to experience changes in perception, mood, consciousness, and cognition. They want to feel better or at least subdue any emotional pain they may be experiencing. Many are suffering from anxiety, depression, and intense stress, or have experienced trauma.

The perceived relief from these conditions comes at a steep price. Addiction comes with the development of tolerance and with withdrawal symptoms. The addicted person starts to experience intense physical cravings for the substance and an emotional obsession to use alcohol and drugs regardless of the consequences. The substance abuse becomes the very pain it was supposed to control.

At the same time, the addictive behavior causes very problematic physical and mental side effects. Alcohol attacks your organs. Injecting substances without the benefit of medical training or clinical supervision can cause a lethal overdose or serious infections. Furthermore, all of the most widely misused substances can induce psychosis—the user loses touch with reality and sees, hears, or believes things that aren’t real.

Psychotic symptoms can result from intoxication on alcohol, amphetamines (and related substances), cannabis (marijuana), cocaine, hallucinogens, inhalants, opioids, phencyclidine (PCP) and related substances, sedatives, hypnotics, and other substances. Psychotic symptoms can also result from withdrawal from alcohol, sedatives, hypnotics, and other substances.


Alcohol is the most commonly used addictive substance in the United States, says the National Council on Alcoholism and Drug Dependence. “17.6 million people, or one in every 12 adults, suffer from alcohol abuse or dependence along with several million more who engage in risky, binge drinking patterns that could lead to alcohol problems.”

Over time, excessive alcohol use, both in the form of heavy drinking or binge drinking, can lead to numerous health problems, chronic diseases, neurological impairments, and social problems.

Acute alcohol intoxication often involves impaired motor functions, confusion, and disorientation. Ceasing substantial alcohol consumption that has continued for several days or weeks may lead to both physical and psychological withdrawal symptoms. Common symptoms include insomnia, anxieties, and phobias. More serious withdrawal symptoms may include hallucinations.

In severe cases of alcohol use disorder, psychosis may develop—typically after longer periods of abuse. One of these psychoses is called delirium tremens, colloquially known as DTs. Symptoms include anxiety and insomnia, and sometimes also withdrawal convulsions. As the patient's state deteriorates, his level of consciousness decreases, he becomes incoherent, and he loses the sense of time and place. She may suffer from intense auditory, optical, and tactile illusions, as well as from delusions that feel very real to her. Restlessness, trembling, and excessive activity of the sympathetic nervous system (e.g., sweating and palpitations) are also common.

Alcoholics often see insects and arachnids on the walls or their bodies and experience tactile hallucinations—a feeling that bugs are crawling across their skin. This symptom is known as formication (derived from Formicidae, the scientific name for ants). Chronic misuse of specific drugs can generate similar hallucinations, which are known as “cocaine bugs” and “crank bugs” (in the case or long-term amphetamine use).


“Numerous lines of evidence suggest a correlation between cannabis consumption and a variety of psychiatric conditions, including cannabis-induced psychosis,” write Ruby Grewal, MD, and Tony George, MD, on

Psychiatrist Kevin Hill writes in Marijuana, “stories of marijuana users experiencing psychotic symptoms like hallucinations are common… The hallucinations can be short lived and go away on their own, or they can be the beginning of a lifetime of problems with these symptoms.”

Despite these risks, a large number of Americans now believe using cannabis is mostly harmless. This has led to increasing legalization of marijuana across the United States. Dr. Hill describes the notion that cannabis is harmless as a “myth”:

“Excellent scientific research shows that regular marijuana use affects the ability to think, can increase feelings of anxiety and depression, and increases the odds that one will develop psychotic disorders such as schizophrenia.” (Marijuana p. 44)

The more frequent the use and the more potent the cannabis product, the higher the risk. The potency of cannabis is determined by measuring levels of delta-9-tetrahydrocannabinol or THC, the main psychoactive ingredient that gives marijuana users the “high.” In the 1970s, joints averaged a concentration of about one percent. In the early 1990s, the typical THC concentration had increased to three percent. Now it often exceeds 15 percent. Concentrates such as butane hash oil can reach THC concentrations of 80–90 percent.


Another “party” drug considered safe by most of its users is “ecstasy” (MDMA). Its effects include euphoria, enhanced sociability, and heightened mental awareness. Serious adverse reactions are rare, but “MDMA use has been associated with various medical complications such as renal and liver failure, rhabdomyolysis, disseminated intravascular coagulation, hepatitis, cerebral infarction, seizures, delirium, fulminant hyperthermia, intracranial bleed, cerebral edema, and coma,” report Ankit Patel, MD, et al. “Adverse psychiatric symptomatology associated with MDMA includes panic attack, depression, suicidal ideation, flashbacks, rage reactions, psychosis, and severe paranoia.”

Psychedelic Drugs

Psychedelic drugs are psychoactive drugs whose primary function is to alter the thought processes of the brain. Many psychedelic drugs are thought to disable filters that block or suppress signals related to everyday functions from reaching the conscious mind.

The most famous psychedelic drug is lysergic acid diethylamide (LSD), first produced by Swiss chemist Albert Hofmann in 1938. LSD is derived from ergotamine, a chemical from the fungus ergot. Hofmann was also the first person to synthesize the principal psychedelic mushroom compounds psilocybin and psilocin.

Initially seen as a possible psychiatric wonderdrug and venerated by artists as a creativity pill, LSD was used in psychotherapy for many years in the 20th century. Despite the initially high expectations, the use of hallucinogens for medicinal purposes ended in the mid-sixties. Their psychotic effects were just too unpredictable.

Even Hofmann’s first self-experiment with LSD in 1943 induced intense feelings of anxiety, alternating in his beliefs that one of his neighbors was a malevolent witch, that he was going insane, and that the drug had poisoned him.

More recently, designer drugs such as “flakka” has been reported to cause intense psychotic episodes. In 2015, the Miami Herald reported on a “man high on flakka” who attacked a police officer, proclaimed himself the Norse god Thor, and attempted to have sex with a tree.

Seek Help

Substance-induced psychotic episodes are extremely dangerous. Losing touch with reality can cause serious injury and death. If you or a loved one have ever experienced drug-induced psychosis, seek help as soon as possible. Continuing the misuse of psychoactive substances will likely lead to more psychotic episodes and could induce persistent psychosis. It may also mean that a substance use disorder has developed.

If you feel you may require addiction treatment, don’t delay seeking help. Call The Farley Center at Williamsburg Place in Virginia to find out what treatment options are available. The Farley Center offers superior addiction treatment services to individuals from all walks of life. Farley offers detoxification and short-term stabilization in a residential-like setting, as well as more flexible partial hospitalization with a varied length of stay. Patients benefit from psychotherapy—individually and in a group setting—experiential therapeutic interventions, integration into a 12-Step recovery program, and education to launch them into recovery from addiction.