How close you are to your family or how detached you are determine the scale of trauma you are exposed to, a new study on earthquake survivors shows.

The study by Turkey's Behavioral Sciences Institute (DBE) focuses on role of trauma, power of family bonds and mental problems resulting from the 1999 Marmara earthquake. The 7.4-magnitude earthquake in Turkey's northwest killed thousands of people and devastated small towns. It was the biggest natural disaster in recent years for a country prone to earthquakes. The DBE's study indicates that family affairs are the single-most important factor to determine whether trauma effects survivors permanently or in the short term.

Researchers interviewed and examined more than 400 earthquake survivors in İzmit, Yalova and Adapazarı, three cities affected most by the earthquake, and witnessed that the effects of the trauma were still in place 20 years after the disaster and that there were still people with symptoms of post-traumatic stress disorder (PTSD).

The study revealed that the loss of loved ones, financial difficulties, mental health disorders dating back before the disaster, and pre-earthquake and existing health problems affected the PTSD symptoms of survivors as well as their capacity to fight trauma and existing fears of a new earthquake.

The main factor affecting this capacity was negative developments regarding the family, the study shows. Results show those who lost close relatives had more PTSD symptoms than those who lost their immediate families. The study concludes that family was the determining factor on whether the trauma would linger and that adapting to post-disaster life was easier for survivors thanks to significant contributions of surviving relatives like uncles, aunts and nephews.

DBE President Emre Konuk told Anadolu Agency (AA) said that they observed a group of people that still relive the effects of the earthquake despite the passing of 20 years. "Some still cannot sleep without the lights on and some cannot sleep at all. Others prefer sleeping after 3 p.m. [the time of earthquake], and some start crying while speaking about the earthquake. Interestingly, there are also survivors with no PTSD symptoms at all," he said. Konuk said their theory was that traumatic processes within family aggravated post-disaster trauma, making it permanent. Those "familial" traumatic processes include domestic violence, sexual abuse, drug use, mental health problems and divorce.

Konuk said the less a familial traumatic process is, the less traumatic toll the earthquake left on survivors is.