What is schizophrenia?

The link between alcohol and schizophrenia has been a hotly debated topic for decades. We have definitive evidence that people with schizophrenia are more likely to abuse substances like alcohol, nicotine, cannabis, or other illicit drugs. The question of whether alcohol or drug abuse can cause schizophrenia is a much more complicated subject.

Schizophrenia is a serious mental disorder that affects a person’s ability to think, feel, and behave in line with reality. The two most common symptoms of schizophrenia are hallucinations (hearing or seeing things that are not real) and delusions (fixed, false beliefs). People with schizophrenia experience mental distortions in perception, emotions, sense of self, and language. This can result in extremely disordered thinking that impairs daily functioning. They may also present abnormal behavior like wandering aimlessly, self-neglect or appearing dishevelled, and mumbling or laughing to themselves. Research shows that people with schizophrenia are two to three times more likely to die early than the general population.

Alcohol-induced psychosis and schizophrenia

Alcohol-related or alcohol-induced psychosis is a medical condition that shares many of its characteristic symptoms with schizophrenia. It occurs when a person continually consumes large amounts of alcohol over time. People with alcohol-induced psychosis generally experience hallucinations or delusions immediately after alcohol use. Alcohol-induced psychosis is not a mental health disorder but a form of secondary psychosis that is brought on by external substances. In most instances, its symptoms subside when the alcohol consumption or withdrawal ends. 

Sometimes, people may incorrectly diagnose alcohol-induced psychosis as schizophrenia. Despite common symptoms, these are two separate disorders that are rarely seen together in the same person. The Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-V) specifies that for a true schizophrenia diagnosis, the symptoms cannot be caused by the use of substances such as drugs or alcohol. Even for qualified health professionals, it is difficult to differentiate between schizophrenia and alcohol-induced psychosis without an accurate history of the patient.

Does alcohol cause schizophrenia?

Alcohol use disorder (AUD) is the most common disorder that occurs with schizophrenia. Almost 50% of people with schizophrenia will develop a substance use disorder during their lifetime. One of the most prominent theories on why alcohol misuse and schizophrenia co-occur is that people with schizophrenia turn to alcohol to self-medicate.

Alcohol dulls the senses for everyone. People with schizophrenia may see this as a great relief as they become less aware of what they are experiencing. Studies show that people with schizophrenia also experience a greater euphoria or joyfulness from drinking alcohol. As a result, people with schizophrenia are likely to drink more alcohol to blunt their symptoms and increase their sense of well-being. Researchers have found that alcohol abuse can worsen schizophrenia symptoms like auditory hallucinations (hearing things that aren’t there) and paranoid delusions (unreasonable feelings of being threatened or victimized).

Some studies discovered that the first episode of schizophrenia often follows alcohol abuse. This suggests that alcohol can trigger schizophrenia in people who are already at a high risk of developing the disorder. A recent study also found that people with an alcohol use disorder are 3.38 times more likely to develop schizophrenia later in life. However, this data is not enough to prove a cause-and-effect relationship between schizophrenia and alcohol abuse. It could be that people who are at a high risk of developing schizophrenia are more likely to abuse alcohol, or that some people are vulnerable to both schizophrenia and AUD.

Schizophrenia and drug abuse

Researchers have known about the strong association between alcohol and schizophrenia for decades. Not only are people with schizophrenia more likely to abuse drugs, but substance abuse is clearly linked with an increased risk of developing schizophrenia later in life. A large-scale study conducted with 3,133,968 individuals in Denmark found that the increased risk of developing schizophrenia is:

• 5.2 times with cannabis
• 3.4 times with alcohol
• 1.9 times with hallucinogenic drugs like LSD, ecstasy, and ketamine
• 1.7 times with sedatives such as Xanax, Valium, Ativan, and Ambien
• 1.24 times with amphetamines
• 2.8 times with other addictive substances

The authors of this study report that the true relationship between mental illness and drug abuse is likely to be incredibly complex. More research is needed to understand whether drug or alcohol abuse can cause the onset of schizophrenia in some individuals.

Treatment for schizophrenia and alcohol misuse

Alcohol can become an unhealthy coping mechanism for people struggling to manage symptoms of schizophrenia. When people with schizophrenia attempt to give up alcohol, the symptoms are likely to get worse. In addition to the schizophrenia symptoms, they may also experience alcohol withdrawal symptoms like nausea, tremors, anxiety, and in severe cases, hallucinations and seizures. This makes it very dangerous for them to try and give up alcohol on their own. 

If a loved one is dealing with both alcoholism and schizophrenia, watch out for signs and behaviors such as:

• Isolation
• Decline in self-care
• Self-harm
• Aggression or violence
• Missing work, school, or other appointments
• Repeated hospital visits

As schizophrenia and alcohol abuse occur together so frequently, it is crucial to treat both conditions at the same time. A dedicated treatment program that addresses both disorders will lower the chances of a relapse and improve quality of life significantly. While problems with alcohol can be treated with rehab programs, treatments and medications for schizophrenia are likely to be lifelong.