Post-traumatic stress disorder (PTSD) manifests following either direct or indirect exposure to actual or threatened death, serious injury, or sexual violence.
Events such as natural disasters (earthquakes, mudslides, fires, floods, tsunamis, tornadoes), war, domestic violence, rape, violent crime, accidents, and medical procedures may trigger the development of PTSD. In the 2013 revision of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-5), PTSD was included as part of a new chapter on trauma- and stress-related disorders; in previous editions of the DSM, PTSD had been classified as an anxiety disorder.
According to the National Center for PTSD at the US Department of Veteran Affairs, the estimated lifetime prevalence of PTSD among American adults in 2021 was approximately 7 to 8 percent, and the lifetime prevalence of PTSD was about 4 percent among men and 10 percent among women.
Dissociative Identity Disorder and Trauma
Dissociative identity disorder (DID) is a psychological disorder that is included in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders under the category of Dissociative Disorders. DID is estimated to afflict from 1% to 3% of the population and occurs in cases of severe childhood trauma, such as ongoing childhood sexual abuse and/or severe physical abuse and thus is included as a trauma disorder.
Individuals who meet criteria for DID experience the existence of two or more distinct identities or personality states (referred to as alternate identities), with the number of reported identities ranging from 2 to over 100. In most cases, there is a primary identity that uses the person's birth name, and this identity is often described as passive, dependent, guilty, and depressed. The alternate identities often have characteristics that are different from the primary identity.
With DID, each of the identities has its own unique way of perceiving and relating to the self, to others, and to the environment. At any given time, the individual's behavior is controlled by one of these personality states, and the personality states may transition from one state to another in sequence.
The person with DID is unable to remember important information about themself, which is not the normal forgetfulness that everyone experiences from time to time. For example, while a person without DID may forget what she did on her birthday 10 years ago, a person with DID may not remember anything about what happened yesterday afternoon, may not remember buying the dress hanging in the closet that she purchased last week, may not remember meeting the person she met that morning, and so forth.
It is diagnosed three to nine times more often in women than men, and females tend to have a higher number of alternate identities than males.
Alternate identities are parts of the personality that are not connected to each other (are dissociated) in the subjective experience of the individual. They may be of varying ages and genders, with widely varying vocabulary, thoughts, memories, attitudes, behaviors, feelings, and interpersonal patterns of relating. Patients with DID may refer to these alternative identities by different terms, including parts, aspects, selves, multiples, and so forth. They may report varying levels of awareness of existence of other identities, ranging from no awareness to complete awareness; they may be critical of each other and may be in conflict with each other. For example, one identity may verbalize much animosity toward another identity, and vice versa.
The Psychological Impact of Trauma
People with histories of serious childhood abuse can develop severe personality disorders. They can also develop self-injurious behaviors, in which they may cut or burn themselves. Dissociative symptoms are also fairly common. These involve feelings of unreality and disconnection from mental and physical experience. There is a striking lack of awareness of certain feelings, thoughts, or actions. In extreme cases, people might develop dissociative identity disorder (previously known as multiple personality disorder), in which they literally believe that they have several different personalities within their own body.
While a natural disaster such as Hurricane Katrina or the tsunami of 2004 can have profound emotional impact on the survivors, there is a uniquely destructive effect from trauma that is caused by other people, specifically if there was intention to cause harm. We are profoundly social animals and a good deal of our psychology is devoted to the negotiation of interpersonal relationships. If we suffer significant harm at the hands of another person, that can throw our entire worldview into doubt. Are people still good? Can other people be trusted? While the loss of a sense of safety regarding our physical surroundings can be enormously frightening, we do not expect morality from the weather. A natural disaster does not in itself threaten our fundamental belief in the decency of humanity. When people lose trust in other people, they can suffer from deep depression and social alienation.
In the face of stress, the HPA axis is activated. It sends out stress hormones, known as glucocorticoids. These serve to activate the autonomous nervous system, making our heart pump faster, our breath more rapid and shallow, and blood rush to our large muscle groups from our small muscle groups. This allows our body to respond rapidly to threat.
In normal circumstances, our parasympathetic nervous system acts to restore this system to a resting state, allowing our body to recover from the stress reaction. However, with trauma, the whole stress system can be thrown out of whack, causing abnormalities within the HPA axis, and keeping our autonomic nervous system (specifically the sympathetic nervous system) on overdrive. This has the effect of wearing down the body, compromising the immune system, and putting undue stress on many parts of the body's regulating systems. In childhood, when the brain is not fully developed, severe trauma can interfere with the brain's actual development, causing long-term damage.
With more chronic childhood trauma, the therapy takes more time and needs to move more slowly. The therapy should first address any severe problems with functioning, such as self-mutilation, suicidality, and severe personality pathology. Only when the patient can tolerate talking about the trauma without becoming overwhelmed by painful emotion or developing dangerous symptoms, should the therapy address the trauma directly. With some people this can happen fairly quickly, with others it might take years. Some people with very fragile emotional and behavioral control may never fully process the trauma. Instead, the therapy will focus on shoring up self-control capacities and the general ability to function.
