Why Is Drinking Before Age 15 So Risky? What Science Says About Alcohol and Teenagers

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Alcoholism in teenagers, which doctors call alcohol use disorder (AUD), is uncommon at these ages, and what prevails is risky drinking, such as getting drunk and binge drinking.

In Mexico, one in five adolescents aged 10 to 19 drinks, and in Spain just over half of students aged 14 to 18 drank alcohol in the past month.

This guide brings together official data from both countries, what is known about the effect of alcohol on a brain that is still developing, warning signs for families, and what the evidence says about prevention.

Does alcoholism exist in teenagers?

Yes, although it is much less common than occasional drinking. The clinical term is alcohol use disorder, and it is diagnosed using the 11 DSM-5 criteria, with mild, moderate, or severe degrees (NIAAA, 2025).

In the United States, the 2024 NSDUH national survey estimated that 775,000 young people aged 12 to 17, or 3.0%, had this disorder in the past year (NIAAA, 2025). In Mexico and Spain, official surveys mainly measure how much and in what way adolescents drink.

The classifications of the disorder and its degrees are explained in the article on the types of alcoholism.

How many teenagers drink alcohol in Mexico and Spain?

In Mexico, the 2022 National Health and Nutrition Survey found that 20.6% of adolescents aged 10 to 19 drank alcohol. In addition, 13.9% had engaged in excessive drinking in the past year and 5.2% in the past month, and drinking increased with age and with socioeconomic level (Ramírez-Toscano et al., 2023, Salud Pública de México).

In Spain, the ESTUDES 2025 survey of students aged 14 to 18 found that 51.8% drank alcohol in the past month, 17.2% got drunk during that period, and 24.7% had engaged in binge drinking. The average age of the first drink was 13.9 years (Ministry of Health, 2025).

Data from Spain’s Ministry of Health. The 2025 figures for getting drunk and binge drinking are the lowest since 2000.

The drop in getting drunk over two years amounts to a relative reduction of about 17%.

[math]\dfrac{20.8 – 17.2}{20.8} \times 100 \approx 17\%[/math]

Globally, the WHO estimates that 23.5% of young people aged 15 to 19 drank alcohol in 2019, with figures of 45.9% in Europe and 43.9% in the Americas (WHO, 2024).

What does alcohol do to the teenage brain?

The brain keeps developing well into a person’s 20s, and the prefrontal cortex, which is involved in planning and decision making, is one of the last areas to mature (NIMH).

One review describes adolescence as a period of neurodevelopment that is especially vulnerable to alcohol (Lees et al., 2020, Pharmacology Biochemistry and Behavior).

A review published in Nature Reviews Neuroscience associates drinking in adolescence with problems in attention, verbal learning, and memory, and with changes in the development of gray and white matter (Spear, 2018, Nature Reviews Neuroscience).

The author cautions that some differences already existed before drinking began, so they are risk factors and not only effects.

The review by Lees et al. (2020) also found that heavy or binge drinking is associated with poorer learning, memory, and attentional control, and with a faster loss of gray matter volume.

Does starting to drink earlier increase the risk of alcoholism?

The NIAAA warns that people who start drinking before age 15 are at greater risk of developing alcohol use disorder later in life (NIAAA, 2026).

In a large US survey, more than 40% of those who started drinking at age 14 or younger developed alcohol dependence at some point in their lives, compared with about 10% of those who started at age 20 or older (Grant and Dawson, 1997, Journal of Substance Abuse).

In that study, the odds of dependence fell by 14% for each year later that drinking began. The risk was higher with a family history of alcoholism, at 57.3% with onset at age 13 or younger versus 15.6% with onset at age 21 or older (Grant, 1998, Alcohol Health and Research World).

A study of 8,746 twins suggests that this entire association is explained by familial, genetic, and environmental factors, and that delaying the age of onset probably would not prevent dependence (Prescott and Kendler, 1999, Alcoholism, Clinical and Experimental Research).

Another analysis of 43,093 adults, adjusted for a family history of alcoholism, smoking and other drug use, and childhood antisocial behavior and depression, among other factors, still found a higher risk of dependence, with a hazard ratio of 1.78, in those who started before age 14 compared with those who started at age 21 or older (Hingson et al., 2006, Archives of Pediatrics and Adolescent Medicine).

Causes and risk factors

The NIAAA notes that prevention must take into account genetics, personality, rate of maturation, level of risk, and the social and environmental setting, and that many young people drink because of peer pressure, a desire for independence, or stress (NIAAA, 2026). It also warns that many have easy access to alcohol.

Parents have an influence through their example. The CDC indicates that teenagers drink more when their parents drink, especially if the parents binge drink (CDC, 2025).

Advertising also plays a role. A review of 12 studies with 35,219 participants found, in every one of them, an association between exposure to alcohol marketing and greater drinking among young people, and some studies also found an association with starting to drink (Jernigan et al., 2017, Addiction).

Consequences of alcohol in teenagers

The immediate consequences are the most serious. MedlinePlus lists car crashes, falls and drownings, suicide, violence, sexually transmitted infections, unplanned pregnancies, and sexual assault (MedlinePlus, 2026).

In the United States, excessive drinking causes about 4,000 deaths a year among people under 21, according to data from 2020 and 2021 (CDC). In the long term, there are also the effects on the brain and a higher risk of dependence in adulthood.

Warning signs for parents

The NIAAA suggests that families and teachers pay attention to mood changes with anger or irritability, academic or behavioral problems at school, rebelliousness, and changes in friend groups. They should also watch for a lack of energy and a loss of interest in activities or in personal appearance (NIAAA, 2026).

The most direct signs are finding alcohol among their belongings, smelling alcohol on their breath, problems concentrating or remembering, slurred speech, and lack of coordination. The NIAAA warns that these changes are often a normal part of growing up and that sometimes they can indicate a problem with alcohol.

How to prevent alcohol use in teenagers

The family interventions listed by the NIAAA include helping parents set clear rules against drinking and enforce them, and improving communication about alcohol.

A review of 77 studies adds parental modeling, limiting access to alcohol, supervision, and a good family relationship as factors that delay the start of drinking (Ryan et al., 2010, Australian and New Zealand Journal of Psychiatry).

The evidence on family prevention programs is weaker than was thought. A 2019 Cochrane review of 46 studies with 39,822 participants found no clear benefits on young people’s drinking, with evidence of low or very low quality (Gilligan et al., 2019, Cochrane).

In schools, the results of 53 trials were mixed, and the most frequent positive effects were on getting drunk and binge drinking, with programs such as Life Skills Training, Unplugged, and the Good Behaviour Game (Foxcroft and Tsertsvadze, 2011, Cochrane).

What does the law say in Mexico and Spain?

In Mexico, Article 220 of the General Health Law prohibits selling or supplying alcoholic beverages to minors, and the age of majority is 18. The Mexican beer industry runs campaigns against sales to minors, such as No te hagas güey.

In Spain, the sale of alcohol to minors is regulated by the autonomous communities, and Galicia, for example, passed a law protecting the health of minors in 2025 that prohibits selling and supplying alcohol to them.

In March 2025, the Spanish government approved a national bill on preventing alcohol use among minors (Ministry of Health), which lapsed in Congress without being passed.

Where can you get help?

In Mexico, the Línea de la Vida helpline answers free of charge at 800 911 2000, 24 hours a day, and family members can call too. In Spain, the first step is the pediatrician or the family doctor at the local health center.

In case of possible severe alcohol poisoning, with vomiting, slow or irregular breathing, confusion, or difficulty staying conscious, call 911 in Mexico or 112 in Spain without waiting for all the symptoms to appear. Do not leave the person alone and, if they are unconscious, turn them on their side (NIAAA).

Frequently Asked Questions (FAQ)

1. What is alcoholism in teenagers?

It is alcohol use disorder in minors, which is diagnosed using the 11 DSM-5 criteria. It is uncommon, and in the United States it affected 3.0% of young people aged 12 to 17 in 2024.

2. What causes alcoholism in teenagers?

Contributing factors include genetics, personality, family history, peer pressure, stress, easy access to alcohol, and advertising. Parental drinking, especially binge drinking, is associated with more drinking by their children.

3. What are the consequences of alcohol in teenagers?

In the short term, accidents, violence, suicide, and risky sexual behavior. In the long term, it is associated with memory and attention problems and with a higher risk of dependence in adulthood.

4. At what age do teenagers start drinking?

In Spain, the average age of first use is 13.9 years according to the ESTUDES 2025 survey. Those who start before age 15 are at greater risk of dependence in adulthood, and studies debate how much of this is due to age and how much to family factors.

5. How can alcoholism in teenagers be prevented?

By setting clear rules, improving communication, setting an example, limiting access, and keeping track of who they spend time with. In schools, the most frequent positive effects of prevention programs are on getting drunk and binge drinking.

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