We often wish we had the ability to select what information to remember and what to forget from our report. And when faced with happy experiences, we often wish we could erase traumatic events forever. However, this extraordinary capacity is still far beyond our reach. Traumatic events are intense negative events that arise suddenly, unexpectedly and uncontrollably and, by endangering the physical or psychological integrity of the person who is sample unable to cope with them, have dramatic consequences for the victim (especially in the form of terror and helplessness). Within traumatic events, mass terrorist attacks are of special interest both because of the magnitude of the psychological consequences caused in the victims and their environment, as well as because of the unexpected, harmful, atrocious and intentional nature of the attack itself. Taking as an example the March 11, 2004 attack in Madrid, several programs of study have presented quantitative and qualitative analyses on the current status of the victims. These studies have mainly determined that, although most victims do not develop mental disorders and are able to recover without significant psychopathological sequelae, a high percentage suffer from post-traumatic stress, depressive or anxiety disorders.

Due to the aggressiveness and the difficulty of assimilation after suffering a traumatic status , a series of psychological and biological processes occur, where, for example, the brain is so biochemically disorganized that its innate capacity to process stressful experiences is overwhelmed. The initial shock phase is often accompanied by partial or total amnesia, together with an alteration of the nervous system that produces, among others: insomnia, nightmares, episodes in which the traumatic event is relived, startle and alert reactions or hypervigilance, feelings of guilt, anxiety and/or panic, deep sadness or isolation. As time progresses, cognitive changes are also reported, for example, in the way of perceiving the world. The feeling that everything is dangerous, that human beings cannot be trusted, the feeling of injustice, makes the traumatized person's life turn gray, making it much more difficult to return to normality in their lives. After this phase, the victim tries to process the experience little by little until it is assimilated.

Despite knowledge of both the psychopathological repercussions of mass terrorist attacks and the need for their treatment, it was not until after the 9/11 attacks in New York that experimental programs on both issues began to be developed. Recent scientific literature on psychological treatments for victims of mass terrorist attacks reveals that there are very few programs of study at present that demonstrate the efficacy or effectiveness of such therapies. However, the few existing effectiveness programs of study agree that trauma-focused psychological treatments are effective and should be considered today as the most appropriate treatment for victims of terrorist attacks suffering from post-traumatic stress disorder. Alternatively, pharmacological treatments are beginning to be tested, although it is still too early to determine their efficacy. Finally, in addition to the limited specific literature, the samples reported by these programs of study represent victims who have recently suffered the terrorist attacks, so it is complicated to know the usefulness of treatment in victims suffering from the disorders in the very long term deadline, i.e., 20 or 30 years after suffering an attack. Therefore, the evidence seems to indicate that although the traumatic experience is not forgotten, in some way, with time and with the help of psychological treatment financial aid in most cases, it is possible to process it until it is remembered with a much lighter emotional intensity, being able to return to normal day-to-day life.