Alcohol-Induced Blackouts: Effects, Risk Factors & Dangers

Key Takeaways

• Alcohol-induced blackouts are memory lapses due to alcohol’s disruption of memory consolidation, particularly in the hippocampus.
• There are two types of blackouts: ‘en bloc’ with complete amnesia and ‘fragmentary’ with partial memory loss.
• Blackouts can range from forgetting a single conversation to several hours and are a warning sign to reassess alcohol use.
• Binge drinking significantly increases the risk of blackouts, which are reported by about half of drinkers.
• Factors contributing to blackouts include alcohol quantity, consumption rate, and individual biological differences.
• Genetics may predispose individuals to blackouts, with some genetic variations linked to this susceptibility.
• Blackouts have both immediate and long-term health effects.
• Preventative measures include moderating alcohol intake and understanding personal limits.
• Treatment options for frequent blackouts include professional help, behavioral therapies, and medications.

What Are Alcohol-Induced Blackouts?

An alcohol-induced blackout is a clinical condition characterized by the inability to recall events that occurred while intoxicated despite maintaining consciousness during the episode. This phenomenon is medically defined as a “gap” in one’s memory for events that transpired while under the influence of alcohol. Drinking high amounts of alcohol is the primary cause of blackouts. This level of intoxication keeps your brain from transferring short-term memories to long-term memory. 

Blackouts are not to be confused with “passing out,” or loss of consciousness. People experiencing blackouts can appear completely normal to everyone around them, as they are still able to talk and move around. It is only later, when the person who blacked out cannot remember doing or saying things while they were intoxicated, that they realize anything is amiss. 

However, if that person were to continue drinking, the blackout could lead to passing out. Losing consciousness while drinking is a sign of alcohol overdose, so it is important to seek medical attention for that individual if they pass out.

Symptoms of Alcohol Blackouts

Identifying the signs of an alcohol blackout may be difficult, if not impossible. Those who black out may talk to people, drive cars, spend money, have unprotected sex, and more. They just will not be able to recall these events later. 

However, you may be able to tell if someone is “blackout drunk” by these other signs of severe intoxication:

• Drowsiness
• Dizziness
• Disorientation
• Headache
• Slurred speech
• Disturbances in vision
• Impaired balance
• Staggering gait
• Vomiting

Types of Alcohol-Induced Blackouts

Alcohol-induced blackouts, complex conditions involving memory impairment during intoxication, are categorized into two primary types: fragmentary and en bloc blackouts. 

Fragmentary Blackouts

Fragmentary blackouts, also called “grayouts” or “brownouts,” are the most common form of blackout. They are characterized by incomplete memories of events while under the influence of alcohol. These memories can be patchy with clear ‘islands’ of recall, interspersed by periods of amnesia. During such blackouts, individuals might still be able to perform tasks but cannot later recall those actions.

En Bloc Blackouts

En bloc blackouts are the more severe form of memory loss caused by excessive alcohol consumption. They involve a complete inability to recall events during intoxication due to the disruption of the hippocampus’s role in memory consolidation. 

Causes of Alcohol-Induced Blackouts

Alcohol-induced blackouts have several contributing factors related to both drinking behaviors and genetics.

Alcohol Consumption and Blackouts

The amount and speed at which one drinks alcohol are closely connected to the occurrence of alcohol-induced blackouts. When blood alcohol concentrations (BACs) rise rapidly — such as with binge drinking or drinking on an empty stomach — cognitive abilities become significantly impaired. In most cases, blackouts begin at BACs of about 0.16% or higher. 

Combining Medications With Alcohol

While binge drinking plays a significant role in blacking out, combining alcohol with other medications that affect memory can increase the risk of blackouts at much lower BACs. These medications include: 

• Benzodiazepines
• Sleep medications like zolpidem (Ambien)
• Marijuana

Genetic Influences on Alcohol-Induced Blackouts

Emerging research in the field of genetic epidemiology has revealed that genetics can significantly influence an individual’s susceptibility to alcohol-induced blackouts. Studies indicate that there is a heritable component to these blackouts, suggesting that some individuals may be genetically predisposed to experiencing memory lapses following alcohol consumption. A study found that roughly 43% of the liability for blackout occurrence can be attributed to genetic factors, with the remaining influenced by nonshared environmental factors.

What Happens to Your Body When You Black Out?

Clinical research has demonstrated that blackouts typically arise when alcohol levels in the bloodstream spike sharply, overwhelming the brain’s ability to transfer short-term memories into long-term storage. This process, crucial for memory consolidation, occurs in the hippocampus, a region of the brain highly sensitive to alcohol’s effects. Studies have found that binge drinking or high-intensity drinking, which involves consuming alcohol at levels significantly above the binge-drinking thresholds, is a common precursor to blackout events.

During such episodes, the individual remains conscious and may continue to engage in activities, but the ability to form new explicit memories — those of facts and events —  is significantly impaired. This type of memory loss is known as “anterograde amnesia.” This contrasts with the retention of established memories or the capacity to hold new information in short-term memory, which is less affected by acute alcohol use.

Are Blackouts a Sign of an Alcohol Use Disorder?

These experiences underscore the potent impact that excessive alcohol intake can have on cognitive functions. While blackouts are not necessarily a sign of an AUD, it is important to recognize that they can serve as a warning sign of excessive alcohol consumption. This is especially true if your personal life is being greatly affected by alcohol-related consequences. Therefore, this behavior may warrant a reevaluation of one’s drinking habits and possibly medical intervention. 

Awareness and education about the risks associated with high levels of alcohol intake are crucial in preventing the occurrence of alcohol-induced blackouts and their associated risks.

How Do Alcohol-Induced Blackouts Affect Your Life?

Binge drinking and high-intensity drinking that results in blacking out can potentially lead to various short- and long-term health and lifestyle effects. 

Short-term health effects of excessive drinking can include: 

• Alcohol poisoning
• Accidents with resulting injuries (car crashes, falls, drowning, etc.) 
• Violent behavior (suicide, homicide, assault, intimate partner violence, etc.)
• Legal or financial trouble as a result of criminal behavior or accidents
• Unplanned pregnancy or sexually transmitted illnesses from unprotected sex
• Miscarriage, stillbirth, or fetal alcohol spectrum disorders (FASDs) in pregnant women

Over the long term, misusing alcohol can contribute to various chronic diseases and other serious issues. These can include: 

• Alcohol use disorder 
• Colorectal cancer
• Female breast cancer
• Heart disease or high blood pressure
• Liver cancer
• Liver disease
• Memory problems
• Mental health conditions, such as anxiety and depression
• Mouth, throat, esophagus, and voice box cancer
• Pancreatitis
• Interpersonal problems with family, school, or work
• Stroke

How to Avoid Alcohol-Induced Blackouts

Preventing alcohol-induced blackouts is crucial for both immediate safety and long-term health. The National Institute on Alcohol Abuse and Alcoholism (NIAAA) highlights the importance of understanding one’s personal limits and moderating alcohol intake as key strategies. To avoid temporary memory impairment from heavy drinking, here are several evidence-based tips:

• Understanding the risks: Educate yourself about the dangers of high-intensity drinking, which involves consuming double the amounts that define binge drinking.
• Start with moderation: Limit alcohol consumption and drink slowly over a longer period rather than consuming large quantities quickly. Familiarize yourself with the standard drink guidelines from the Centers for Disease Control and Prevention (CDC) to better limit your drinking.
• Know your limits: Be aware of how much alcohol leads to impairment for you and plan to stay within these limits.
• Healthy alternatives: Engage in activities that don’t involve drinking, providing alternative ways to socialize and relax.
• Accountability: Go out with friends who understand your limits and can help ensure you stay within them.
• Professional help: If you find it difficult to control your drinking, consider talking to a healthcare provider or seeking support from alcohol treatment programs.

If you find yourself struggling to limit your drinking, quitting alcohol altogether may be your best option for preventing blackouts and regaining control of your life.

Treatment Options for Alcohol-Induced Blackouts

For those who frequently experience alcohol-induced blackouts, treatment is a critical step toward recovery and preventing further damage. Treatment options may include behavioral therapies, medications, and lifestyle modifications. 

• Cognitive-behavioral therapy (CBT): CBT is often used to help individuals modify their drinking behaviors and address any underlying psychological issues that may contribute to excessive alcohol use. 
• Motivational interviewing: This is another therapy method that can encourage individuals to change their drinking patterns by addressing their ambivalence about alcohol use.
• Medication-assisted treatment (MAT): Medications like naltrexone or acamprosate may be prescribed in a treatment facility to reduce cravings and withdrawal symptoms. These medications can make it easier for individuals to abstain from or reduce alcohol intake. Medications should be used in conjunction with therapy and are not a stand-alone treatment for excessive drinking.
• Lifestyle changes: These may include a support network, sober activities, and coping strategies to deal with situations that might lead to heavy drinking. 
• Alcohol rehab: If you feel you have become dependent on alcohol and have noticed that blackouts are affecting your life, it may be time to check into a qualified alcohol rehab facility. Treatment options include medical detox, inpatient and outpatient care, partial hospitalization, intensive outpatient programs, and more.

Get Alcohol-Induced Blackouts Under Control

Are your blackouts from alcohol misuse getting out of hand? The best way to regain control is through evidence-based, compassionate addiction treatment.

Alcohol addiction can be difficult and potentially dangerous to recover from on your own. Severe alcohol withdrawal can be deadly, so heavy alcohol users should not attempt to wean off alcohol without the help of a professional medical detox facility. Alcohol addiction treatment will begin with a detox period that focuses on managing any uncomfortable or severe withdrawal symptoms that arise. After detox ends, patients begin a rehab program that teaches them how to cope without alcohol and maintain sobriety.

Detox and rehab can take place in inpatient or outpatient settings. Outpatient treatment is best for mild alcohol addictions, and it allows patients to attend doctor and therapy visits while still living at home. Inpatient treatment is best for moderate to severe alcohol addictions or people who have relapsed. Inpatient treatment involves living on-site at the detox or rehab facility, an approach that keeps patients in a healing environment and allows for better monitoring and treatment.

The Recovery Village Cherry Hill at Cooper provides a full continuum of care, from medical detox and inpatient rehab to aftercare. We are here to help you and those you love recover from addiction and begin a healthier, alcohol-free future. Contact us to learn more about alcohol addiction treatment programs that can work well for your needs in recovery.

Frequently Asked Questions About Blackouts