**7. Consequences**

It is important to realize on the long term, that alcohol and substance abuse tend to track on into early adulthood and that alcohol use at a young age is a predictor for future alcohol use (31).

Adolescent drinkers are more likely than their non-drinking or experimenting peers to have school problems, drugs or engage in criminal activities such as stealing. In a follow up study carried out 10 years later, adolescents who had consumed alcohol were still more often involved in problem behaviors including unreliable work attendance, substance use problems, violent behavior and illegal activities during early adulthood. Early experimenters were also at higher risk than non-drinkers to have problems with substance use and criminal and violent behavior (32).

Heavy drinking has been shown to affect neuropsychological performance and could impair the growth and integrity of the brain structures. During adolescence, the part of the brain that is developing in particular is the frontal lobe. Here, the higher cognitive functions such as cognitive processing and executive functions are located (33;34).

Research with functional magnetic resonance imaging (fMRI) demonstrates that memory, attention and visuospatial abilities are negatively affected by alcohol. Alcohol and drug abusers perform worse than their peers (35). Increased vulnerability for these neurologic effects is seen in women, patients with a family history of alcohol use disorders, heavy episodic drinkers and alcohol use combined with drug use. The co-occurrence of psychiatric disorders is an important factor to consider in the evaluation of neurocognitive functioning in patients with alcohol abuse. As was mentioned before causality is not clear. The role of time of abstinence and age of first drink seem to be less related to neurologic damage (36).

Importantly, as young adulthood is a period when most people make important educational, occupational and social decisions, an impaired cognitive function could significantly affect their futures.

Alcohol use increases the risk of high-risk sexual intercourse. Young adolescents report that alcohol has caused them to engage in unplanned sex (27). Girls in particular are prone to participate in sexual relationships more readily, and even against their will, during intoxication. Afterwards, they often regret the incident and it is not uncommon that they are traumatized.

Alcohol consumption is one of the leading preventable causes of death in the United States (37). The WHO recently identified alcohol use amongst young people (10-24 years) as the most important factor contributing to disability adjustable life years (DALY's) (38). In particular, consumption of alcohol is associated with injuries and accidents, which are major contributors to mortality of adolescents.

Apart from the psychiatric disorders discussed before, alcohol use is also associated with medical conditions such as hepatitis and liver cirrhosis, hypertension, pancreatitis, cardiomyopathy, pneumonia and tuberculosis. Also cancers of the mouth, esophagus, pharynx, larynx and breast are more common in patients with excessive alcohol consumption. Neurologic disease is not uncommon, and alcohol use is associated with peripheral neuropathy and myopathy, as well as with central nervous diseases such as dementia and stroke.
