Previous trials have shown that omega-3s can improve memory, mood, concentration and behaviour.
Researchers in the UK will supplement 38 pupils, aged 10 to 16, with the oils for six months and closely follow their behaviour.
The children have problems like attention deficit disorder (ADD), attention deficit hyperactivity disorder (ADHD), autism, dyslexia, Asperger's syndrome and pervasive development disorder.
Some of them have already been prescribed drugs like Ritalin, used to treat ADD and ADHD, but which also has side effects like decreased appetite and insomnia. The new study will also examine whether fish oil supplements can help reduce the side effects of this medication.
The findings will be analysed by Dr Madeline Portwood, a senior educational psychologist working for Durham county council.