Overgenerality memory style for past and future events and emotions related in bipolar disorder. What are the links with problem solving and interpersonal relationships?

Impaired risk avoidance in bipolar disorder and substance use disorders

Comorbid substance use disorders are highly prevalent in bipolar disorder, and research suggests that individuals with the comorbid presentation typically have worse outcomes than individuals with bipolar disorder without this comorbidity. However, psychosocial treatments for the comorbid presentation have not demonstrated effectiveness for both mood and substance use symptom domains, suggesting novel treatments are needed. An alternative path to treatment development is to identify mechanisms that underlie comorbid bipolar disorder and substance use disorders that can subsequently be targeted in treatment. We evaluated neurocognitive markers for impairments in risk avoidance (the tendency to engage in a persistent pattern of problematic behaviors despite negative outcomes resulting from such behaviors) as potential mechanistic variables underlying negative illness outcomes in the comorbid population. Participants with bipolar disorder (n = 45) or comorbid bipolar disorder and substance use disorders (n = 31) in a relatively euthymic mood state completed clinical risk behavior assessments, task-based risk avoidance assessments, and neurocognitive assessments. Results indicated a lack of notable between-group differences in the clinical risk composite score, task-based risk avoidance assessments, and neurocognitive assessments, with the exception of self-reported executive dysfunction which was elevated among the comorbid sample. Collapsing across group, we found that increased discounting of delayed rewards, older age, and an earlier age of (hypo)mania onset predicted an increased clinical risk composite score. These findings underscore the potential importance of delay discounting as a novel mechanistic target for reducing clinical risk behaviors among individuals with bipolar disorder both with and without comorbid substance use disorders.

Emotional autobiographical memory impairment features in three mental disorders

We proposed the Emotional Autobiographical Memory Test (EAMT) as a specialized method for measuring emotional autobiographical memory impairment in patients with mental disorders. The EAMT was tested with 32 patients with schizophrenia, 18 patients with bipolar disorder, 32 patients with depression, and 42 people undiagnosed with such disorders. We extracted 13 indices of five kinds of features from participants' emotional autobiographical memory and compared them among the four groups. The overgeneralization result in the schizophrenia and depression groups was consistent with previous results, supporting the EAMT's validity. However, inconsistent with previous results, overgeneralization was not found in the bipolar disorder group. Further, the count of involuntary memories in the patient groups (vs. control group) was significantly smaller, which can guide future researchers in investigating the psychopathology of mental disorders.

How to project oneself without positive and integrated memories? Exploration of self-defining memories and future projections in bipolar disorder

Bipolar disorder (BD) is a disabling disorder with functional impact on everyday life. Recent studies suggest that autobiographical memory impairment may contribute to the maintenance of psychopathology, leading to enduring altered self-construct. Moreover, past personal experiences also support the ability to project oneself into the future to pre-experience an event, this capacity can be modified by psychiatric disorders. Self-defining memories and future projections by accessing highly significant events that are vivid and focused on central goals or enduring concerns can both provide a better understanding of the impact of disorders on self-perception and on the ability to project oneself into the future. Therefore we proposed to explore self-defining memories and future projections in BD patients (n = 25) compared to control participants (n = 25). BD patients' self-defining events were associated with more tension, life-threatening events, and negative emotion. BD patients also reported less integrated past but not less integrated future self-defining events. And their future projections were more closely related to leisure, and associated with positive emotions, compared to controls. For both groups, the future projections were less specific, integrated, and tense than the memories. These results question the self-coherence of patients' identity and should be confirmed to propose appropriate interventions to project oneself adaptively into the future and contribute to a better outcome.

Cognitive mechanisms of episodic simulation in psychiatric populations

Episodic simulation is the construction of a mental representation of a specific autobiographical future event. Episodic simulation has increasingly been studied in psychiatric populations. Here we 1) review evidence indicating that episodic simulation is compromised in patients with depression, anxiety, schizophrenia, bipolar disorder, and PTSD; and 2) consider several potential cognitive mechanisms of episodic simulation in psychiatric populations: episodic retrieval, scene construction, mental imagery, components of the CaRFAX model (i.e., capture and rumination, functional avoidance, and executive functioning), and narrative style. We evaluate evidence regarding these mechanisms across psychiatric populations, and identify areas of future research. Understanding the factors that contribute to episodic simulation impairment in psychiatric populations may lead to targeted and effective treatment approaches.

Remediating reduced memory specificity in bipolar disorder: A case study using a Computerized Memory Specificity Training

OBJECTIVES

Reduced autobiographical memory specificity (rAMS) is a vulnerability factor found across unipolar depression (UD), posttraumatic stress disorder (PTSD), eating disorder, schizophrenia, and bipolar disorder (BD). A group delivered psychological therapy training called Memory Specificity Training (MeST) remediates rAMS in UD and PTSD, with additional downstream effects on related psychological processes and symptoms. Its impact in BD is unknown. In this case study, we examined the impact of a computerized version of MeST (c-MeST) on improving AMS and related symptoms and processes in participant with rapid cycling type I BD.

METHOD

An experimental case study with an ABA design was used. During baseline (14 days, Phase A), the training phase (nine sessions across 17 days, Phase B), and a 1-month follow-up (Phase A), memory specificity, depressive symptoms, and related processes and symptoms were repeatedly measured.

RESULTS

Memory specificity increased significantly after the participant completed c-MeST. Session-to-session scores indicated that AMS improved most from the in-person baseline assessment to the first online session. All other measures of processes and symptoms deteriorated during the training phase but regressed to baseline during follow-up.

CONCLUSION

Memory specificity was improved as indicated by increased AMS from pre-intervention measurement to 1-month follow-up. Other improvements in symptoms were not observed. Rather, some related maladaptive psychological processes and symptoms worsened during the training phase and regressed to baseline during follow-up.

Autobiographical memory deficits in remitted patients with bipolar disorder I: The effect of impaired memory retrieval

Autobiographical memory (AM) has been studied extensively in different psychiatric disorders. However, less is known about AM in bipolar disorder (BD). Aim of the present study was to investigate BD patients' ability to recall episodic and semantic autobiographical memories after controlling for the effect of other possible neurocognitive deficits. Participants included 30 clinically remitted outpatients with BD type I and 30 healthy controls, matched for age, gender and educational level. Autobiographical memory was examined by the Questionnaire of Autobiographical Memory. Premorbid intellectual functioning, verbal memory, verbal fluency, attention and working memory were also assessed. Bipolar patients were impaired in both episodic and semantic AM, compared with healthy individuals. Deficits involved recall of memories from childhood-adolescence, early adulthood and recent life. Additionally, patients were impaired in verbal memory compared with controls. Differences between study groups in both episodic and semantic AM remained significant even after controlling for the effect of verbal memory deficits. Remitted BD-I patients showed deficits in recalling personal episodic memories and facts dating to three different life periods. These deficits were independent of patients' lower verbal memory performance. Additional research is required to gain a better understanding of the pattern and the mechanisms underlying AM impairment in BD.

Differential neural correlates of autobiographical memory recall in bipolar and unipolar depression

OBJECTIVES

Autobiographical memory (AM) recall is impaired in both bipolar depression (BD) and major depressive disorder (MDD). The current study used functional magnetic resonance imaging (fMRI) to investigate differences between healthy controls (HCs) and depressed participants with either BD or MDD as they recalled AMs that varied in emotional valence.

METHODS

Unmedicated adults in a current major depressive episode who met criteria for either MDD or BD and HCs (n=16/group) underwent fMRI while recalling AMs in response to emotionally valenced cue words. Control tasks involved generating examples from a given category and counting the number of risers in a letter string.

RESULTS

Both participants with BD and those with MDD recalled fewer specific and more categorical memories than HC participants. During specific AM recall of positive memories, participants with BD showed increased hemodynamic activity in the ventrolateral prefrontal cortex, posterior cingulate cortex, anterior insula, middle temporal gyrus, parahippocampus, and amygdala relative to MDD and HC participants, as well as decreased dorsolateral prefrontal (DLPFC) activity relative to MDD participants. During specific AM recall of negative memories, participants with BD manifested decreased activity in the precuneus, amygdala, anterior cingulate, and DLPFC along with increased activity in the dorsomedial PFC relative to MDD participants.

CONCLUSIONS

While depressed participants with BD and MDD exhibited similar depression ratings and memory deficits, the brain regions underlying successful AM recall significantly differentiated these patient groups. Differential amygdala activity during emotional memory recall (particularly increased activity in participants with BD for positive AMs) may prove useful in the differentiation of individuals with MDD and BD experiencing a depressive episode.