Fetal Alcohol Syndrome in Adults: Symptoms, Facial Features, and Effects

What Fetal Alcohol Syndrome Is — and How It Develops

Fetal alcohol syndrome is caused by prenatal alcohol exposure. Alcohol is a teratogen — a substance that interferes with normal fetal development. When a pregnant person drinks alcohol, it crosses the placenta and reaches the fetus, where it disrupts the development of multiple organ systems, most significantly the brain and central nervous system.

There is no known safe amount of alcohol during pregnancy. Alcohol can cause fetal damage at any stage of pregnancy, though the timing and pattern of exposure influence which specific brain regions and physical features are affected. First-trimester alcohol exposure is primarily responsible for the characteristic facial features of FAS. Second and third-trimester exposure affects brain growth and connectivity, producing the neurodevelopmental effects that persist through adulthood even when the facial features are absent.

The result is a spectrum of effects — from mild neurodevelopmental differences to severe intellectual disability — that vary based on the amount of alcohol consumed, the timing of exposure, and the genetic characteristics of both the mother and the fetus.

Fetal Alcohol Syndrome Facial Features in Adults

The three sentinel facial features that define full FAS are present at birth and persist into adulthood, though they typically become less visually prominent as facial proportions change with maturity. A trained clinician uses standardized assessment tools — particularly the lip-philtrum guide developed by FAS researchers — to evaluate these features even in adults.

The three diagnostic facial features of FAS:

• Thin upper lip (rank 4 or 5 on the lip-philtrum guide) — the upper lip is significantly thinner than average, with reduced vermilion border definition. In adults, this feature may appear as a notably narrow upper lip compared to facial proportions.
• Smooth or flattened philtrum (rank 4 or 5 on the lip-philtrum guide) — the philtrum is the vertical groove between the base of the nose and the upper lip. In typical development, the philtrum has a defined ridge. In FAS, this groove is smooth or absent — the area between nose and lip appears flat or indistinct.
• Small palpebral fissures — the horizontal measurement of the eye openings (from inner to outer corner) is below normal range for age and ethnicity. In adults, this feature appears as eyes that are proportionally narrower than expected.

Additional physical features that may be present in adults with FAS:

• Smaller head circumference than average (microcephaly), which reflects the smaller brain size associated with severe FAS
• Shorter stature — growth deficiency is a component of the FAS diagnosis
• Flat nasal bridge and midface
• Epicanthal folds (skin folds at the inner corner of the eyes)
• Low-set or abnormally shaped ears
• Minor joint or limb abnormalities

It is important to note that an adult can have all of the neurodevelopmental effects of FASD without having the characteristic facial features. The diagnosis category Alcohol-Related Neurodevelopmental Disorder (ARND) specifically addresses brain effects without prominent facial features. The absence of facial features does not rule out significant prenatal alcohol exposure or its neurological consequences.

If you are looking for celebrities and well-known individuals with fetal alcohol syndrome, see our page on celebrities with fetal alcohol syndrome.

Cognitive and Neuropsychological Effects of FAS in Adults

The neurodevelopmental effects of prenatal alcohol exposure on the adult brain are the most significant and most impairing aspect of FAS, far beyond the visible physical features. Alcohol disrupts the development of brain architecture — the organization of neural circuits, the connectivity between brain regions, and the development of the prefrontal cortex and corpus callosum in particular.

Adults with FASD commonly demonstrate:

Executive function impairment is the most clinically significant cognitive effect. Executive functions — planning, organizing, initiating tasks, flexible thinking, impulse control, cause-and-effect reasoning — are primarily mediated by the prefrontal cortex, which is particularly vulnerable to prenatal alcohol exposure.

Adults with FASD often have significant difficulty with:

• Planning and organizing multi-step tasks
• Understanding and predicting the consequences of actions
• Impulse control — acting before thinking
• Flexible thinking — switching strategies when something isn’t working
• Time management — understanding that actions have consequences that are separated in time

This impairment in cause-and-effect reasoning is one of the most important features for understanding behavior in adults with FASD. It is not defiance or immorality when someone with FASD repeats behavior that has previously caused them consequences — it may reflect a genuine neurological impairment in the capacity to connect past consequences to present decisions.

Memory differences — Adults with FASD often have difficulty with:

• Working memory — holding information in mind while doing something else with it
• Learning from verbal instruction — auditory processing difficulties mean information needs to be presented in multiple modalities
• Abstract information — concrete, hands-on learning is more effective than abstract verbal explanation
• Procedural memory and routine adherence — inconsistency in executing routines and procedures

Social and adaptive functioning — Social difficulties in adults with FASD include difficulty reading social cues, misunderstanding social norms, susceptibility to peer influence and manipulation (a significant risk factor for legal trouble), and challenges with self-advocacy. Many adults with FASD have been exploited, victimized, or manipulated precisely because of these social processing differences.

Sensory processing differences — Some adults with FASD have heightened sensitivity to sensory input — sound, touch, taste, or light — that can make certain environments difficult to tolerate and that affects social participation.

Mental Health Conditions That Co-Occur with FASD in Adults

Rates of mental health conditions are significantly elevated in adults with FASD:

• ADHD — present in approximately 50 to 65 percent of people with FASD; the attention, impulse control, and hyperactivity symptoms of ADHD overlap substantially with the executive function impairments of FASD
• Depression and anxiety — significantly elevated, partly from the secondary consequences of FASD (social difficulties, academic failure, employment challenges) and partly from FASD’s direct effects on mood regulation circuits
• PTSD and trauma histories — elevated rates; many adults with FASD have experienced significant adverse childhood experiences
• Conduct disorder / antisocial behavior — FASD is a significant but underrecognized factor in the criminal justice system; the impulsivity and cause-and-effect reasoning difficulties of FASD contribute to contact with law enforcement

FASD and Addiction: An Important Connection

Adults with FASD develop alcohol and substance use disorders at significantly higher rates than the general population. Research estimates that 35 to 50 percent of adults with FASD develop substance use problems.

Several features of FASD specifically increase addiction vulnerability:

• The impaired impulse control of executive function deficits makes it harder to resist substance use when opportunities arise
• The cause-and-effect reasoning impairment means that learning from negative consequences of substance use — a primary mechanism by which non-FASD individuals moderate their use — is impaired
• The elevated rates of depression, anxiety, and PTSD create vulnerability to self-medication
• Social isolation and peer influence susceptibility increase exposure to substance-using environments

When someone with FASD is seeking treatment for addiction, the treatment approach needs to account for the specific cognitive profile of FASD. Treatment that relies primarily on insight, abstract reasoning, or the typical “learning from consequences” framework may be less effective. Concrete, structured, skills-based approaches with significant external support and reduced complexity tend to produce better outcomes.

West Georgia Wellness Center treats adults with addiction and co-occurring neurodevelopmental conditions through our integrated dual diagnosis program. Our alcohol addiction treatment program and residential substance abuse program provide the structure and individualized clinical attention that complex presentations require.

Prevention: Alcohol Use During Pregnancy

Fetal alcohol spectrum disorders are completely preventable. The only way to prevent FASD is to avoid alcohol entirely during pregnancy. There is no established safe amount of alcohol at any stage of pregnancy. Guidance from the CDC, the American Academy of Pediatrics, and the American College of Obstetricians and Gynecologists is consistent: no alcohol during pregnancy.

If you are pregnant and struggling with alcohol use disorder, accessing treatment is one of the most important things you can do for both yourself and your child. West Georgia Wellness Center’s alcohol addiction treatment program provides medically supervised detox and residential treatment. Call 470-625-2466.