This month’s guest post is by Geert Smid. Geert is a psychiatrist with Foundation Centrum ’45, the Dutch national institute for specialized diagnosis and mental health treatment after persecution, war and violence. He is also a researcher at Arq Psychotrauma Expert Group. Geert completed his PhD on Delayed Posttraumatic Stress Disorder in 2011 with a number of beautiful publications. He’ll make your brain work a little on this very topic:
According to the current edition of the Diagnostic and Statistical Manual of Mental Disorders, delayed posttraumatic stress disorder (PTSD) must be diagnosed in individuals fulfilling criteria for PTSD if the onset of symptoms is at least 6 months after the trauma. The prevalence of delayed PTSD has for a long time remained unclear, and only few studies have examined factors that may explain its occurrence. The findings summarized below are based on prospective investigations in disaster survivors and unaccompanied refugee minors, as well as a comprehensive meta-analysis of prospective studies.
1. About a quarter of PTSD cases is with delayed onset. The results of our meta-analysis showed that delayed PTSD occurs in about one quarter of all PTSD cases. The risk of delayed PTSD did not decrease between 9 and 25 months after the traumatic event, and when traumatized populations were followed up for longer periods of time, more delayed PTSD cases were found. These findings suggest ongoing potential risk for some individuals.
2. During the interval between the trauma and delayed PTSD onset, some symptoms are likely to occur. Delayed PTSD occurred most often in individuals already reporting “subthreshold” symptoms after the traumatic event. These symptoms that precede the full PTSD syndrome are called “prodromal.” Prodromal symptoms may include intrusive memories and avoidance of reminders as well as feelings of depression and anxiety.
3. Delayed PTSD is associated with mental health service utilization. We found a high likelihood of mental health service utilization in participants endorsing delayed PTSD 4 years after a disaster. Two thirds of disaster survivors endorsing delayed PTSD used or continued using mental health services. This finding strongly suggests that symptom progression in delayed PTSD is clinically relevant.
4. Delayed PTSD can be explained from pre-existing, trauma-related, and posttraumatic factors. Survivors reporting total home destruction after a disaster, i.e. very severe disaster exposure, were at elevated risk of developing delayed PTSD. We also found that cognitive ability as indicated by higher education was associated with delayed PTSD after a disaster, presumably by promoting initial adaptation to the traumatic event and thus mitigating initial distress. Lack of perceived social support as well as new stressful life events several years after a disaster increased the risk of delayed disaster-related PTSD.
In unaccompanied refugee minors, increasing age emerged as a risk marker for delayed PTSD. This highlights the importance of the stressful transitions for these youths at the age of 18 years. For example, their legal status will be reviewed, and they will be uncertain regarding their future right to remain in theNetherlands. Thus, factors associated with delayed PTSD may be pre-existing, trauma-related, or related to the posttraumatic phase.
These factors may explain the occurrence of delayed PTSD in one of three ways. First, factors may increase the risk for PTSD in general. Second, factors may promote initial adaptation to the traumatic event and thus explain why symptoms are not full-blown from the start. Third, factors may precipitate PTSD onset despite initial adaptation and thus explain why symptoms increase in number or severity later on.
5. Severe traumatic event exposure may lead to stress sensitization. We found prospective evidence of stress sensitization, that is, enhanced reactivity of individuals to new stressors following extreme disaster exposure (such as total home destruction) during the first years after a disaster. Stress sensitization may explain progression of distress over time and has important practical implications. Averting foreseeable stressors and resource losses in the aftermath of severe trauma, diminishing the impact of chronic stressors as well as reducing stress sensitization may be a target for preventing and treating progression of posttraumatic distress.
Towards a better definition of delayed PTSD.
According to the latest proposal for DSM-5, PTSD “With Delayed Expression” is defined as follows: “if the diagnostic threshold is not exceeded until at least 6 months after the event (although the onset and expression of some symptoms may be immediate).” Compared with previous DSM editions, this definition is a clear step forward, because it explicitly allows for prodromal symptoms preceding the onset of full delayed PTSD. Thus the revised definition more realistically describes the possible delayed impact of traumatic events that may show a crescendo pattern over time. This is important, because effects of trauma or stressor exposure are likely not restricted to PTSD alone, but to be relevant to a wide range of psychopathology. For example, delayed trajectories of depression have also been found following a disaster, and stress sensitization has been implied in the development of psychosis.
Do you think stress sensitization could be involved in the development of depression?
And could the concept of stress sensitization be helpful in developing innovative treatment strategies for trauma- and stressor-related disorders?
Reference of the meta-analysis:
Smid GE, Mooren TT, van der Mast RC, Gersons BP, & Kleber RJ (2009). Delayed posttraumatic stress disorder: systematic review, meta-analysis, and meta-regression analysis of prospective studies. The Journal of Clinical Psychiatry, 70 (11), 1572-82 PMID: 19607763