The objectives of this project are as follows:

1. To assess whether omega-3 dietary supplementation for six months can reduce externalizing behavior problems (antisocial and aggressive behavior) in schoolchildren aged 8 to 18, both at the end of treatment and six months post-treatment
2. To assess whether omega-3 supplementation is more effective in children with more psychopathic-like traits.

Externalizing behavior problems (aggressive and antisocial behaviors) are widely recognized as predisposing to significant mental health problems and violence among adolescents in secondary schools. These in turn result in enormous economic and social costs to schools as well as to society. These costs include mental illness, crime, and violence. Similarly, violence is widely recognized as a major public health problem which has also largely defied successful intervention and prevention. Because an increasing body of research is documenting health and neurobiological risk factors for aggression and violence, part of this prevention failure may be due to intervention efforts ignoring biological contributory factors which include impaired neurocognitive and psychophysiological functioning. One benign biological intervention that may help attenuate behavior problems in children consists of omega-3 supplementation of the diet, a long-chain fatty acid critical for brain structure and function.

The overarching aim of this study is to assess whether omega-3 supplementation can reduce the base level of externalizing behavior problems in children and adolescents. A secondary but important aim is to assess whether any behavioral improvement may be greater in more psychopathic children. The specific aims are as follows:

1. To assess the effectiveness of omega-3 dietary supplementation in reducing externalizing behaviors in adolescents.
2. To assess whether omega-3 supplementation leads to greater improvement in children with psychopathic-like traits.

Hypotheses will be tested in a placebo-controlled, double-blind, randomized trial involving 8 to18 year-old adolescents drawn from primary and secondary schools in Hong Kong. Omega-3 supplementation will be in the form of a Norwegian fruit juice drink. 300 adolescents will be randomly assigned into: (1) omega-3 supplemented drink, (2) placebo drink, (3) treatment-as-usual controls. Behavioral measures will be assessed at baseline (0 months), end of treatment (6 months), and 6 months post-treatment (12 months).

Inclusion Criteria:

• children and adolescents between the age 8 and 18
• participants who does not fit in any of the following exclusion criteria

Exclusion Criteria:

• unwilling to participate in a randomized, double-blind, placebo controlled trial,
• unable to give written, informed parental consent and assent from children,
• on medication that may modify lipid metabolism in the past 3 months
• significant use of omega-3 supplements in the past 6 months
• seafood allergies
• mental retardation
• epilepsy

all participants and research assistants are blind to condition for the two fruit juice groups