More support is needed to prevent babies and young children developing mental health problems in later life, leading doctors say.
Their report shows there is growing evidence that intervening very early on - from conception to the age of five - may help stop conditions arising or worsening.
The Royal College of Psychiatrists is calling for more specialist services.
The government says the mental health of children and parents is paramount.
Officials say they are investing more in expanding NHS services, alongside funding programmes designed to support children and caregivers.
NHS data shows about 5% of two to four-year-olds struggle with anxiety, behavioural disorders and neurodevelopmental conditions including ADHD.
