Dissociation and Forensic Psychology

How can you tell if a party is truly dissociating, or just pretending to do so to benefit their case? Since dissociation during a traumatic event is common, forensic psychologists play a vital role in determining credible reports of dissociation from cases of malingering in which individuals are looking to escape liability for violent actions.

The DSM-5 defines dissociation as a disruption in the normal integration of consciousness, memory, identity, emotion, perception, and behavior. We all have experienced episodes of dissociation (e.g. daydreaming), but those with dissociative disorders will describe a different experience. For instance, their dissociative symptoms are intrusive, cause distress, and impair daily functioning. Dissociative disorders are characterized by the presence of positive symptoms (e.g. flashbacks, fragmentation of identity), which are intrusions that disrupt awareness and the stability of one’s subjective experiences. Individuals may also experience negative symptoms (e.g. amnesia) in which one is unable to recall or control information about the self that should otherwise be easily accessible or controllable.

While the cause of dissociative disorders remains unknown, one leading theory involves exposure to traumatic experiences, particularly during childhood. Psychodynamic theory suggests there is a splitting of awareness in the wake of trauma. Stressful and traumatic memories become repressed within the subconscious as a protective mechanism. Knowledge for those events remains inaccessible, but may emerge later in the form of distinct personalities like we see in dissociative identity disorder. Essentially, dissociation is used as a coping behavior during or following times of trauma or extreme stress. In addition, imaging studies have found biological evidence for dissociative disorders. One model for dissociative amnesia by Stanilou and Markowitsch suggests activation of brain chemicals at the wrong time can negatively influence the way we process information. One study focused on hormones our body uses to help metabolize sugar. These hormones also play an important role in forming and retrieving memories. Researchers found individuals with dissociative amnesia had lower levels of sugar utilization in an area of the brain responsible for remembering autobiographical information.

Fortunately, the prevalence of clinically diagnosed dissociative disorders is rare, but there is cause for concern in the court room regarding claims of amnesia and dissociation during violent crimes. Comprehensive reviews of past research have found associations between higher levels of dissociation and increased violence. Among 105 individuals who had committed violent crimes, 20 percent reported partial or complete amnesia for the most violent portion of the assault. Individuals were often able to recall events before the violence, but had a specific cutoff for when their amnesia began. Occurrences of dissociation and dissociative amnesia in cases of extreme violence spark legal questions about an offender’s responsibility for the crime and their fitness to stand trial.
Psychologists must do a combined clinical and forensic evaluation when dissociation has been raised. They should ask about the offender’s background history, such as previous declines in mental functioning and harmful coping behaviors. An offender of a violent crime does not need to have previously experienced a dissociative episode, but that may help substantiate their claims, especially among individuals with severe PTSD. Special considerations should be taken among offenders with criminal backgrounds or who have been previously incarcerated. Additionally, psychological assessments should take into consideration all relevant information (e.g., the offender’s personal character, context regarding the crime, and accounts from a variety of sources). Other information relevant to both the forensic and legal aspect of the case include mental health prior to the incident, use of legal/illegal substances, and any history with dissociative experiences. Psychological testing should include standard testing measures as well as tests of malingering.

Forensic experts must remain aware of potential discrepancies in the offender’s story regarding their amnesia or dissociative experience. For instance, inconsistencies or implausible claims such as complete amnesia (which is rare) can signal possible deception. Evaluators must go beyond assessing the past (e.g. the offender’s mental capacity at the time of the crime) and consider the possible influence of new information on the individual’s memory. The presentation of evidence or police reports can retroactively skew the recall of past events. Legal cases have demonstrated dissociation is likely to occur during violent crimes; however, it is up to forensic experts and the court to decide whether criminal behavior is admissible based on extensive forensic evaluations.