Higher levels of a lessened sense of reality and being easily immersed can occur. Causes
The exact cause of depersonalization is unknown, although biopsychosocial correlations and triggers have been identified. It has been thought that depersonalization can be caused by a biological response to dangerous or life-threatening situations which causes heightened senses and emotional numbing. Psychosocial
There is growing evidence linking physical and sexual abuse in childhood with the development of dissociative disorders. Childhood interpersonal trauma – emotional abuse in particular – is a significant predictor of a diagnosis of DPDR. Compared to other types of childhood trauma, emotional abuse has been found to be the most significant predictor both of a diagnosis of depersonalization disorder and of depersonalization scores, but not of general dissociation scores. Some studies suggest that greater emotional abuse and lower physical abuse predict depersonalization in adult women with post-traumatic stress disorder (PTSD). Patients with high interpersonal abuse histories (HIA) show significantly higher scores on the Cambridge Depersonalization Scale, when compared to a control group. Earlier age of abuse, increased duration and parental abuse tend to correlate with severity of dissociative symptoms. Besides traumatic experiences, other common precipitators of the disorder include severe stress, major depressive disorder, panic attacks, and psychoactive substances. People who live in highly individualistic cultures may be more vulnerable to depersonalization, due to threat hypersensitivity and an external locus of control. Neurobiology
There is converging evidence that the prefrontal cortex may inhibit neural circuits that normally form the basis of emotional experience.
Spontaneous improvement occasionally happens and some juxta-articular lesions do not progress to collapse. Other treatments include immobilization and osteotomy of the femur. Cancellous bone grafts are of little help. Prognosis
If the diver has not been exposed to excessive depth and decompression and presents as DON, there may be a predisposition for the condition. Diving should be restricted to shallow depths. Divers who have suffered from DON are at increased risk of future fracture of a juxta-articular lesion during a dive, and may face complications with future joint replacements. Because of the young age of the population normally affected, little data is available regarding joint replacement complications.There is the potential for worsening of DON for any diving where there might be a need for decompression, experimental or helium diving. Physically stressful diving should probably be restricted, both in sport diving and work diving due to the possibility of unnecessary stress to the joint. Any diving should be less than 40 feet/12 meters. These risks are affected by the degree of disability and by the type of lesion (juxta-articular or shaft). Prevalence
Dysbaric osteonecrosis is a significant occupational hazard, occurring in 50% of commercial Japanese divers, 65% of Hawaiian fishermen and 16% of commercial and caisson divers in the UK. Its relationship to compressed air is strong in that it may follow a single exposure to compressed air, may occur with no history of DCS but is usually associated with significant compressed air exposure.