Overgeneral autobiographical memory

Overgeneral autobiographical memory (OGM) is an inability to retrieve specific memories from one's autobiographical memory. Instead, general memories are recalled, such as repeated events or events occurring over broad periods. For example, when asked to recall a happy event, a person who exhibits OGM may say, 'when I was on vacation last month' instead of remembering a single incident, such as, 'my high school graduation.' Research shows a correlation between OGM and certain mental illnesses, such as major depressive disorder (MDD) and posttraumatic stress disorder (PTSD). Overgeneral autobiographical memory (OGM) is an inability to retrieve specific memories from one's autobiographical memory. Instead, general memories are recalled, such as repeated events or events occurring over broad periods. For example, when asked to recall a happy event, a person who exhibits OGM may say, 'when I was on vacation last month' instead of remembering a single incident, such as, 'my high school graduation.' Research shows a correlation between OGM and certain mental illnesses, such as major depressive disorder (MDD) and posttraumatic stress disorder (PTSD). The most common way to test for OGM is with the autobiographical memory test (AMT). A participant views cue cards with varying emotional cues (happy, sad, excited, scared, etc.) and is then asked to think of a specific memory in response to it. Most studies utilize the ten word paradigm on the cue cards, where five words are positive and five are negative, but some studies include neutral words (such as fashion or uncle), which increases the total number of cue words. After presentation of the cue word, participants are given 30 seconds to one minute, depending on the study, to come up with a specific memory. If unable to think of a specific memory, the participant is further prompted to think of one specific time or episode, often by the researcher using the phrase 'can you think of a specific time—one particular occasion.' Memories are considered specific if they occurred once, during a specific time. Responses are normally recorded and transcribed for later coding of overgeneral memories or specific memories.Certain studies code based on the two types of overgeneral memories: categoric and extended memories. Categoric memories include events that occur repeatedly throughout one's life. An example of a categoric memory is 'when I went to the store.' An extended memory includes events that last more than a day. The memory 'when I traveled abroad last year' would be an example of an extended memory. Not all studies differentiate between the two, however. There are two criticisms over the current research methods for OGM. One involves the use of the AMT, as it is believed that it may not be sensitive enough to detect OGM in nonclinical samples. Additionally, most studies utilizing the AMT use the same cue words, which could be problematic if certain words elicit more OGM than others. It is recommended that varying words in the AMT across studies or the use of additional measures, such as sentence-completion or a different cuing procedure, be utilized in the future to avoid any possible confounds due to the AMT. Secondly, there is a debate between coding OGM through the low number of specific memories ('low memory specificity') or through the high number of overgeneral memories ('high memory overgenerality'). Currently, these two constructs are considered the same within research, but there is cause for concern that they are not equal. In controlling for the possible difference, many meta-analyses will separate research studies based on which variable they use to code for OGM. Many research studies have shown a close association between depression and OGM. A study in 1988 found that in-patients with a primary diagnosis of Major Depressive Disorder were more likely to display OGM as compared to a healthy control group. This was the first study of its kind to research the phenomenon of OGM in depressed individuals; prior to this study, OGM had only been found in patients who had attempted suicide. In 2007, a meta-analysis performed by Williams et al. show that OGM is highly associated with depressive symptoms across many studies. In fact, an overgeneral memory is found not only in individuals with MDD, but also in other affective disorders including postpartum depression, dysphoria, and bipolar disorder. While the 1988 study was influential for the course of future research on OGM and depression, it could not explain why OGM was more common in the depressed individuals, an issue that still plagues OGM research today. Though the causal direction of the relationship between OGM and depression is still uncertain, the presence of an overgeneral memory predicts the course and maintenance of depressive symptoms. For individuals who have seemed to recover from depression, memory often remains overgeneral. In addition, there is evidence that higher levels of OGM predict even greater depressive symptoms up to seven months later. There is considerable evidence that OGM maintains depressive symptoms and acts as a vulnerability factor for future recurrence. Failure with interpersonal problem solving, increased rumination, difficulties imagining the future, and avoidance of negative emotions are all associated with OGM and are believed to be key factors in the maintenance of depression. Due to the vast research on depression and OGM, it has been widely accepted that an overgeneral memory is a risk factor for future episodes of depression and can influence the maintenance and length of depressive episodes. Much like in depression, OGM has been associated with trauma and PTSD symptoms, as well as the onset and maintenance of PTSD. However, there has been some debate on whether or not trauma alone is sufficient for the development of OGM, or if PTSD symptoms are necessary. An initial study by Kuyken and Brewin found that patients who had reported past childhood sexual abuse, a trauma, were more likely to exhibit increased OGM as compared to participants who reported no abuse or only physical abuse. PTSD symptoms, however, were not reported in this sample. In effort to locate the particular effects of PTSD, McNally and colleagues compared OGM occurrence in Vietnam veterans with and without PTSD. The study found that the veterans with a PTSD diagnosis significantly displayed more OGM, even when depression status was controlled for. This study led credence to the idea that it was the development of PTSD that led to the vulnerability of OGM, and not just exposure to trauma.To focus on this particular issue and figure out if it is trauma exposure or PTSD symptoms that are necessary for the development of OGM, Moore and Zoellner reviewed 24 studies. They concluded that trauma alone is not sufficient to produce OGM and that PTSD symptoms are significantly associated with OGM. While the causal direction between OGM and PTSD is still unknown, Moore and Zoellner conclude that PTSD symptoms, such as intrusive memories and avoidance of reminders, are necessary for OGM. While most initial research focused on OGM in adults, current research is looking at this phenomenon in children. It is hypothesized that childhood trauma could lead to future OGM. Indeed, Williams originally predicted that childhood trauma was necessary for the development of OGM. In 1995, a study looked at the relationship between childhood abuse and current OGM. Participants in the study took the autobiographical memory test and were asked about past sexual and physical abuse. This was the first study that showed a correlation between childhood trauma, specifically sexual abuse, and OGM. A similar study in 2003 corroborated these findings. In a study examining inpatient adolescents, it was found that self-reported abuse was significantly correlated with OGM, especially for positively valenced cues.In effort to avoid retrospective reports on abuse, recent research has been examining OGM in families currently involved with social services. Valentino, Toth, and Cicchetti published a study in 2009 that examined the type of maltreatment a child experienced and current OGM. Participants were recruited via the local Department of Human Services and included families with a substantiated report of abuse or neglect. Compared to both a nonmaltreated group and the neglected group, children who experienced abuse displayed more OGM. In addition to being the first study to look at current maltreatment and OGM, the idea of trauma as a pathway to OGM is significantly supported here, as depression did not mediate the relationship between abuse and OGM. Additionally, neglected children may not have a specific trauma that they attempt to avoid, thus their memory search may not be affected. OGM has been researched in other psychopathological disorders, including anxiety disorder, social phobia, specific phobias, borderline personality disorder and eating disorders without any associations found. It is proposed that OGM is a specific marker of emotional and affect disorders such as depression and PTSD. Initial theories of OGM focused on encoding and retrieval. Memories are encoded based on distinctive traits of what has happened; however, without proper encoding of a memory, the event will not be remembered in any great detail. The hypothesis that stemmed from this idea is that those who have dysfunctional encoding abilities would display greater OGM. With the addition of research on the relationship between depressive symptoms and OGM, the focus shifted. Williams proposed that depressed patients may be more vulnerable to this general encoding style, leaving them with an inability to recall specific aspects of events. However, it was not long until theories on OGM transitioned from a focus on encoding and retrieval to retrieval alone.