People affected by the London suicide bombings are to be assessed for post traumatic stress.
A number 30 bus was blown up in Tavistock Square
An NHS screening service is being offered to those who were injured or bereaved in the attacks.
It will also be available to emergency workers and those who witnessed the 7 July bombings, which killed 52 people and injured 700, or their aftermath.
Those showing trauma symptoms could be offered specialist treatment, including talking therapy, to help them cope.
The NHS Trauma Response (London Bombings) programme will be overseen by the London Development Centre - part of the National Institute for Mental Health in England.
Experts estimate around one in four people directly involved in the bombings may benefit from treatment for traumatic stress.
The main symptoms of post traumatic stress disorder include flashbacks, sleeping problems, anxiety and irritability.
They are common in the immediate aftermath of a traumatic event, but can be problematic if they emerge or continue to persist weeks later.
Professor Chris Brewin, an expert in clinical psychology, who is involved in the specialist trauma response programme in London, said: "It is normal to experience distress after involvement in a traumatic incident such as the London bombings.
"Most people will be coming to terms with the events of July, with the help of their family and friends.
"It is only several weeks after the traumatic incident however, if symptoms of distress don't naturally ease, that you can determine whether someone might benefit from specialist trauma support."
Professor Brewin added: "We know it is best not to rush in and offer counselling to everyone in the immediate days and weeks after an event such as this.
"This can actually prevent people's natural coping mechanism from kicking in.
"It is usually better to allow a period of time before trying to assess what specialist help, if any, people are likely to need."
Levels of stress
Research published in the British Medical Journal last week found almost a third of Londoners suffered serious stress after the 7 July attacks.
It also found that 32% of Londoners said they would now reduce their use of Tubes, trains and buses, and make fewer trips into the centre of the capital.
Health Minister Rosie Winterton said: "The NHS and emergency services responded magnificently to the London bombings on 7 July, and now the capital's mental health services are responding quickly and effectively to meet the long-term needs of victims and witnesses.
"We know from the experiences of those who suffered in other outrages, like Omagh and Madrid, than many victims only start showing symptoms of stress a month or more after the event."
Specialist trauma support is available for people still experiencing problems after the bombings by either contacting a GP or the NHS Trauma Response phone line on 0845 850 2878.