Rescuers search for survivors in Aberfan in October 1966

A new study shows that almost one in three children who lived through the accident in the south Wales mining village continue to suffer problems such as nightmares and difficulty sleeping.

A total of 144 people, including 116 children, died when a coal slagheap slid on to Pantglas Junior School in Aberfan on 21 October 1966.

Some 145 children survived, and although they are now in their late 30s and early 40s, researchers found almost half of them had experienced post-traumatic stress disorder (PTSD) at some point since.

The study, published in the British Journal of Psychiatry, set out to examine the long-term psychological impact of the disaster on the children.

Of the survivors, 41 agreed to take part in the study and they were compared with a "control group" of 72 people of similar age and background.

A section of Aberfan Cemetery is devoted to those killed

The researchers found 46% of the survivors had suffered PTSD, compared to 20% of the control group.

At the time the study was carried out, 29% of the Aberfan survivors met the criteria for continuing to suffer from PTSD.

Some 54% said any reminder of the event brought back feelings and pictures popped into their minds.

Just under half said they thought about it without meaning to and experienced strong feelings about the event.

Symptoms persist

Some 46% said they tried not to think about it and 34% reported continuing bad dreams or difficulty sleeping due to thoughts of the disaster.

The authors of the study said the findings supported previous research which showed that PTSD symptoms can persist into adult life.

Even all these years after the disaster, the intensity of experience, which is a characteristic of PTSD, was still very much present in some of the survivors' lives.

Researchers concluded that children can be affected by traumatic events in a similar way to adults and are not necessarily more adaptable or malleable than adults.