There is a lack of substantial data on the prevalence of gambling and problem gambling among under 18 year olds in the UK. It is not possible to give reliable prevalence figures for problem gambling in childhood. Prevalence studies applicable to young people across the world are difficult to compare because of varying age groups, definitions of gambling and problem gambling, and research design.The studies with the most rigorous design, using large national random samples and recent coverage find the lowest rates.There is no evidence of pools competitions causing problematic behaviours. Patterns of problem gambling. Some believe that the younger the onset of play the more serious gambling problems are likely to become. The current evidence is insufficient to make definitive judgements about this hypothesis. To decide the matter a longitudinal study of gambling is required. Prevalence research suggests that adolescent males are significantly more at risk of gambling and problem gambling as measured by standard problem screening instruments than adolescent females. There are potential factors, which may predispose a child or young person to become a problem gambler - heavy parental gambling, delinquency, regular illicit drug use, and average-to-below school grades - but no direct causal relationship has been reliably established. There is evidence to suggest that several potentially problematic or illicit behaviours which cluster (such as illicit drugs, early drinking and offending) are not atypical during adolescence and may be associated with problem gambling but do not necessarily cause it. There is no strong evidence to support the suggestion that the National Lottery is a 'gateway' to other 'hard' forms of gambling. Older children appear to believe that a greater level of skill is needed to select tickets than younger children. Children report believing they will win large amounts of money. There is an increase in the percentage of underage draw and scratch card buyers who are not being refused their purchase by shopkeepers. Levels of gambling and problem gambling appear to decrease with age. Young people and gambling: Only one study (Ashworth et al, 2000) of gambling behaviour can be generalised to the current population of young people. It found that the majority of young people gamble (70%). There is no evidence to suggest that the majority of under 16 year olds who (illegally) participate in the National Lottery, or legally play machines, are adversely affected. The majority of adolescents recognise the potential dangers of addiction, overspending and debt (Ashworth et al 2000). There is evidence to suggest that lottery and scratch card use changes over time. Ashworth et al (2000) found that these forms of gambling appear to be declining with this age group since they were first introduced. Most children can access online gambling sites. The National Lottery, Ladbrokes and some other sites have effective means of blocking access to under-age gamblers. However, the majority of sites do not have effective screening and blocking technology.