Prospective memory predicts the level of community living skills in schizophrenia

Schizophrenia patients are known to have prospective memory (PM) deficits. There is no robust evidence showing that PM deficits have a major impact on community living skills in schizophrenia. The aim of this study was to examine the association between PM and community living skills in schizophrenia. Forty-four individuals with schizophrenia formed the study sample. Participants? psychopathology, prospective and retrospective memory, level of intelligence, and community living skills were measured with standardized instruments. In bivariate analyses, community living skills overall but not self-care correlated with PM total and subscales scores. In multivariate analyses, event-based PM was more predictive than time-based PM of the level of community living skills. In conclusion, PM has a significant impact on community living skills in schizophrenia and attention should be paid to this type of memory disturbance in rehabilitation of schizophrenia.     

Declarative memory impairment in pediatric bipolar disorder

OBJECTIVES: Impaired verbal declarative memory has been proposed as a trait marker for adult bipolar disorder. However, similar impairments in juvenile-onset bipolar disorder have not been yet documented. Here, we assessed declarative memory in a large sample of clinically well-characterized children with bipolar disorder. METHODS: Forty-one children and adolescents with bipolar disorder [21 bipolar I disorder (BP-I), 10 bipolar II disorder (BP-II), and 10 bipolar disorder, not otherwise specified (BP-NOS)] and 17 demographically matched healthy participants completed a standardized learning and memory test. RESULTS: BP-I children recalled and recognized significantly fewer words than healthy subjects, whereas children with BP-II and BP-NOS did not differ from controls. However, individuals with BP-NOS made more perseverative errors and intrusions than the other groups. Severity of mood symptomatology was not associated with memory performance in any bipolar subtype. CONCLUSIONS: Findings suggest that declarative memory impairments in juvenile BP-I are similar to those seen in the adult form of the illness. These impairments do not appear to be secondary to clinical state; rather, they may reflect trait-related impairments. Distinct performance patterns in BP-I, BP-II, and BP-NOS suggest that the broadly defined phenotype is significantly heterogeneous, and may not be informative for pathogenetic investigations of bipolar disorder.     

Episodic memory impairment in bipolar disorder and obsessive-compulsive disorder: the role of memory strategies

BACKGROUND: There is evidence that individuals with bipolar disorder exhibit neuropsychological impairments not only during mood episodes but also when they are euthymic. One of the most consistently reported cognitive problems in euthymic individuals with bipolar disorder is an impairment in verbal episodic memory. Verbal learning and memory depend on individuals' ability to organize verbal information appropriately during learning. The purpose of the present study was (i) to determine whether episodic memory impairment in euthymic individuals with bipolar disorder is mediated by impairments in organization of verbal information during learning and (ii) to compare the characteristics of memory impairment in bipolar disorder with that previously found in obsessive-compulsive disorder (OCD). METHODS: Study participants were 30 individuals with DSM-IV bipolar I disorder (BP-I), 30 individuals with DSM-IV OCD and 30 normal control participants matched for age, gender and education. Participants completed the California Verbal Learning Test (CVLT), a well-established measure of verbal learning and memory that enables assessment of verbal organization strategies during learning. RESULTS: Compared with control subjects, both BP-I and OCD participants showed impaired performance in long-delayed free recall and verbal organization strategies during learning. BP-I participants showed greater long-delay free recall difficulties but not greater verbal organization difficulties during learning than OCD participants. For OCD participants, the long-delay recall impairment was mediated by difficulties using verbal organizational strategies during learning. In contrast, the group difference in long-delayed free recall between BP-I and control participants remained significant even when semantic clustering was introduced as a mediator. This indicated that BP-I participants' long-delayed free recall difficulties were mediated to a lesser extent by difficulties using verbal organizational strategies than for OCD participants. CONCLUSIONS: Verbal episodic memory problems in individuals with bipolar I disorder and OCD are mediated to different degrees by difficulties using semantic clustering encoding strategies compared with control participants.     

Social skills knowledge and performance among adolescents with bipolar disorder

OBJECTIVES: This study investigated social skills deficits among adolescents with bipolar disorder. METHODS: Adolescents with DMS-IV bipolar disorder (n = 18) and their parents completed social skills assessments when they were experiencing minimal mood symptoms. The control group (n = 18) consisted of adolescents with no history of psychiatric disorders. Participants and their parents rated the adolescents' social performance using the Matson Evaluation of Social Skills with Youngsters. We measured the adolescents' knowledge of appropriate social skills using the Interpersonal Negotiation Strategy Interview. Raters 'blind' to psychiatric status rated the adolescents' responses and their social interactions with an examiner during the assessment. RESULTS: Adolescents with bipolar disorder displayed significantly more social skills performance deficits than controls. No significant differences emerged between the groups in social skills knowledge. Ratings of social interactions with the examiner failed to distinguish bipolar from control teens, but raters were successful in guessing the psychiatric status of the participants. CONCLUSIONS: These findings indicate that bipolar adolescents lag behind their peers in social skills performance, but not social skills knowledge. Results support the hypothesis that difficulties with emotion regulation interfere with the consistent exhibition of appropriate social behaviors.     

Relational memory in psychotic bipolar disorder

Sheffield JM, Williams LE, Cohen N, Heckers S. Relational memory in psychotic bipolar disorder.
Bipolar Disord 2012: 14: 537–546. © 2012 The Authors. Journal compilation © 2012 John Wiley & Sons A/S. Objectives: Recent research has highlighted the phenotypic and genetic overlap of bipolar disorder and schizophrenia. Cognitive deficits in bipolar disorder parallel those seen in schizophrenia, particularly for bipolar disorder patients with a history of psychotic features. Here we explored whether relational memory deficits, which are prominent in schizophrenia, are also present in patients with psychotic bipolar disorder. Methods: We tested 25 patients with psychotic bipolar disorder on a relational memory paradigm previously employed to quantify deficits in schizophrenia. During the training, participants learned to associate a set of faces and background scenes. During the testing, participants viewed a single background overlaid by three trained faces and were asked to recall the matching face, which was either present (Match trials) or absent (Non‐Match trials). Explicit recognition and eye‐movement data were collected and compared to those for 28 schizophrenia patients and 27 healthy subjects from a previously published dataset. Results: Contrary to our prediction, we found psychotic bipolar disorder patients were less impaired in relational memory than schizophrenia subjects. Bipolar disorder subjects showed eye‐movement behavior similar to healthy controls, whereas schizophrenia subjects were impaired relative to both groups. However, bipolar disorder patients with current delusions and/or hallucinations were more impaired than bipolar disorder patients not currently experiencing these symptoms. Conclusions: We found that patients with psychotic bipolar disorder had better relational memory performance than schizophrenia patients, indicating that a history of psychotic symptoms does not lead to a significant relational memory deficit.     

Verbal memory impairment in new onset bipolar disorder: Relationship with frontal and medial temporal morphology

Objectives. Verbal memory (VM) impairment is a trait feature of bipolar I disorder (BDI) that is present at illness onset and associated with functional outcome. However, little is known about the morphological abnormalities underlying this deficit early in the disease course. This study examined the neurobiological correlates of VM impairment in euthymic newly diagnosed patients, with attention to frontal and medial temporal (MT) structures known to contribute to VM. Methods. Euthymic patients with BDI recently recovered from their first episode of mania (n = 42) were compared with healthy subjects (n = 37) using measures of the California Verbal Learning Test (CVLT-II) associated with frontal and MT functioning. A subset of participants had 3T MRI scan (n = 31 patient group, n = 30 healthy subject group). Hippocampal and prefrontal volumes were analyzed using FreeSurfer 5.1 and correlated with their corresponding CVLT-II subscores. Results. Patients showed decreased performance in total learning as well as short and long delay verbal recall. Consistent with MT dysfunction, they also showed deficits in recognition discriminability and learning slope. In the patient group only, left hippocampal volumes were negatively correlated with these measures. Conclusions. These results suggest that anomalous MT functioning is involved with VM impairment early in the course of BDI.     

Neurocognitive impairment in bipolar disorder patients: functional implications

Background: Functional recovery among treated bipolar disorder (BPD) patients is far less likely than syndromal and even symptomatic recovery. We hypothesized that increasingly well‐documented aspects of cognitive impairment may contribute to poor functional outcomes in BPD patients, and reviewed the available research on the topic. Methods: Computerized literature searching identified 12 studies with 13 comparisons that simultaneously evaluated cognitive and functional status in euthymic (n = 8) or non‐euthymic (n = 5 comparisons) adult BPD patients versus otherwise similar healthy controls. Results: In 6/8 studies of euthymic BPD patients and 5/5 studies of non‐euthymic BPD patients, neurocognitive impairment was significantly associated with impaired psychosocial functioning, even after adjusting for residual mood symptoms and relevant demographic and clinical variables. Cognitive status was consistently assessed with standardized, performance‐based neuropsychological tests, but functional status usually was based on subjective self‐appraisals. Approximately 55% of BPD patients were unemployed. Conclusions: Available studies are limited by subjective assessments of functional status rather than objective, performance‐based measures. Nevertheless, they support the hypothesis that enduring aspects of cognitive impairment found even in euthymic BPD patients are associated with inferior functioning. These findings encourage further studies with better assessment methods and greater rehabilitative efforts in BPD patients.     

Differential working memory impairment in bipolar disorder and schizophrenia: effects of lifetime history of psychosis

BACKGROUND: Although bipolar disorder and schizophrenia have long been viewed as distinct illnesses, there is growing evidence that these two complex diseases share some common genes, which may manifest as overlapping neuropsychological impairments. Although working memory dysfunction has been proposed to be central to the pathophysiology of schizophrenia, it has received less attention in studies of bipolar disorder. METHOD: We applied measures of working memory to patients with schizophrenia (n = 15), patients with schizoaffective disorder (n = 15), patients with psychotic (n = 11) and non-psychotic (n = 15) bipolar disorder, and demographically matched healthy subjects (n = 32), in order to determine the extent to which these groups show common or unique impairments. RESULTS: While patients with bipolar disorder (with and without psychotic features) and those with schizophrenia/schizoaffective disorder were impaired on backward digit span, only patients with a lifetime history of psychotic features, regardless of diagnosis, were impaired on spatial delayed response task. CONCLUSIONS: Backward digit span performance is comparable in bipolar disorder and schizophrenia, and may be an appropriate endophenotypic marker that cuts across diagnostic categories. In contrast, spatial working memory performance clearly distinguishes non-psychotic bipolar disorder patients from patients with functional psychosis.     

Functional imaging of emotional memory in bipolar disorder and schizophrenia

Objectives: Although in current diagnostic criteria there exists a distinction between bipolar disorder and schizophrenia, many patients manifest features of both disorders, and it is unclear which aspects, if any, confer diagnostic specificity. In the present study, we investigate whether there are differences in medial temporal lobe (MTL) activation in bipolar disorder and schizophrenia. We also investigate associations between activation levels and symptom severity across the disorders. Methods: Functional magnetic resonance imaging scans were conducted on 14 healthy controls, 14 patients with bipolar disorder, and 15 patients with schizophrenia undergoing an emotional memory paradigm. Results: All groups demonstrated the expected pattern of behavioural responses during encoding and retrieval, and there were no significant group differences in performance. Robust MTL activation was seen in all three groups during viewing of emotional scenes, which correlated significantly with recognition memory for emotional stimuli. The bipolar group demonstrated relatively greater increases in activation for emotional versus neutral scenes in the left hippocampus than both controls and patients with schizophrenia. There was a significant positive correlation between mania scores and activation in the anterior cingulate, and a significant negative correlation between depression scores and activation in the dorsolateral prefrontal cortex. Conclusion: These results provide evidence that there are distinct patterns of activation in the MTL during an emotional memory task in bipolar disorder and schizophrenia. They also demonstrate that different mood states are associated with different neurobiological responses to emotion across the patient groups.     

Neuropsychological functions in patients with bipolar I and bipolar II disorder

Objectives:  The literature reports persistent cognitive impairments in patients with bipolar disorder even after prolonged remission. However, a majority of studies have focused only on bipolar I disorder (BP-I), primarily because bipolar II disorder (BP-II) is often underdiagnosed or misdiagnosed. More attention should be paid to the differences between BP-I and BP-II, especially the aspects of neuropsychological functioning. We examined the different neuropsychological functions in BP-I and BP-II patients and compared them with those of healthy controls.
Methods:  The study included 67 patients with interepisode bipolar disorder (BP-I: n = 30; BP-II: n = 37) and 22 healthy controls compared using a battery of neuropsychological tests that assessed memory, psychomotor speed, and certain aspects of frontal executive function.
Results:  The BP-I group performed poorly on verbal memory, psychomotor speed, and executive function compared to the BP-II and control groups. Both bipolar groups performed significantly less well than the control group on measures of working memory and psychomotor speed, while the BP-II group showed an intermediate level of performance in psychomotor speed compared to the BP-I and control groups. There was no difference between the groups on visual memory.
Conclusions:  BP-I was characterized by reduced performance in verbal memory, working memory, psychomotor speed, and executive function, while BP-II patients showed a reduction only in working memory and psychomotor speed. Cognitive impairment existed in both subtypes of bipolar disorder, and was greater in BP-I patients. Rehabilitation interventions should take into account potential cognitive differences between these bipolar subtypes.     

Investigating brain community structure abnormalities in bipolar disorder using path length associated community estimation

In this article, we present path length associated community estimation (PLACE), a comprehensive framework for studying node‐level community structure. Instead of the well‐known Q modularity metric, PLACE utilizes a novel metric, Ψ^PL, which measures the difference between intercommunity versus intracommunity path lengths. We compared community structures in human healthy brain networks generated using these two metrics and argued that Ψ^PL may have theoretical advantages. PLACE consists of the following: (1) extracting community structure using top‐down hierarchical binary trees, where a branch at each bifurcation denotes a collection of nodes that form a community at that level, (2) constructing and assessing mean group community structure, and (3) detecting node‐level changes in community between groups. We applied PLACE and investigated the structural brain networks obtained from a sample of 25 euthymic bipolar I subjects versus 25 gender‐ and age‐matched healthy controls. Results showed community structural differences in posterior default mode network regions, with the bipolar group exhibiting left‐right decoupling. Hum Brain Mapp 35:2253–2264, 2014. © 2013 Wiley Periodicals, Inc.     

Cognitive impairment in euthymic bipolar patients: implications for clinical and functional outcome

OBJECTIVE: Cognitive impairment in bipolar disorder may be a stable characteristic of the illness, although discrepancies have emerged with regard to what dysfunctions remain during remission periods. The aim of this study was to ascertain whether euthymic bipolar patients would show impairment in verbal learning and memory and in executive functions compared with healthy controls. Secondly, to establish if there was a relationship between clinical data and neuropsychological performance. METHODS: Forty euthymic bipolar patients were compared with 30 healthy controls through a battery of neuropsychological tests assessing estimated premorbid IQ, attention, verbal learning and memory, and frontal executive functioning. The effect of subsyndromal symptomatology was controlled. RESULTS: Remitted bipolar patients performed worse than controls in several measures of memory and executive function, after controlling for the effect of subclinical symptomatology, age and premorbid IQ. Verbal memory impairment was related to global assessment of function scores, as well as to a longer duration of illness, a higher number of manic episodes, and prior psychotic symptoms. CONCLUSIONS: Results provide evidence of neuropsychological impairment in euthymic bipolar patients, after controlling for the effect of subsyndromal depressive symptoms, suggesting verbal memory and executive dysfunctions. Cognitive impairment seems to be related to a worse clinical course and poor functional outcome.     

Spatial working memory function in twins with schizophrenia and bipolar disorder.

BACKGROUND: Family studies are in conflict as to whether schizophrenia and bipolar disorder have independent genetic etiologies. Given the relatively low prevalence (approximately 1%) of these disorders, the use of quantitative endophenotypic markers of genetic liability might provide a more sensitive strategy for evaluating their genetic overlap. We have previously demonstrated that spatial working memory deficits increase in a dose-dependent fashion with increasing genetic proximity to a proband among the unaffected co-twins of schizophrenic patients. Here, we evaluated whether such deficits might also mark genetic susceptibility to bipolar disorder. METHODS: The Wechsler Memory Scale-Revised Visual Memory Span and Digit Span subtests were administered to 46 schizophrenic patients, 32 of their unaffected co-twins, 22 bipolar patients, 16 of their unaffected co-twins, and 100 control twins, representing unselectively nationwide twin samples. RESULTS: Schizophrenic patients and their unaffected co-twins performed significantly worse than control subjects on the spatial working memory task, whereas only the schizophrenic patients performed significantly below the control subjects on the verbal working memory task. Neither bipolar patients nor their unaffected co-twins differed from control subjects on these measures. CONCLUSIONS: Our findings support the hypothesis that impairment in spatial working memory might effectively reflect an expression of genetic liability to schizophrenia but less clearly to bipolar disorder.     

Daily living skills in adolescents with autism spectrum disorder: Implications for intervention and independence

BackgroundChallenges in adaptive behaviors are present in individuals with autism spectrum disorder (ASD), while variation in IQ, social skills, and comorbidities are possible influences on adaptive behaviors. However, adaptive behaviors do not consistently map onto cognitive abilities in ASD, as high IQ is not protective against challenges in adaptive behaviors. Additionally, individuals with both ASD and elevated levels of externalizing problem behaviors experience even worse adaptive behaviors. Identifying factors that contribute to the variance in adaptive behaviors, particularly daily living skills (DLS), may inform strategies to improve adaptive behaviors necessary for independence in adulthood.MethodAdolescents with typical cognitive development (TD, n = 84), intellectual disability (ID, n = 30), or ASD (n = 45) were included in this study to examine group differences in adaptive behaviors, identify relations between IQ and DLS, and determine factors that contribute to variance in DLS at youth age 13. The Vineland Adaptive Behavior Scales, 2nd Edition (VABS-II) was used to measure adaptive behaviors.ResultsAll domains of adaptive behavior were significantly higher in TD groups compared to ASD and ID youth. Significant positive correlations were observed between IQ and DLS in the ASD and ID groups. In the ASD youth group, higher externalizing behavior problems explained the most variance in DLS.ConclusionsDLS are below age-expected levels in young adolescents with ASD, in part because of the higher externalizing behavior problems in this group. Incorporating adaptive skills training and behavior management strategies into current interventions may serve to prepare adolescents and families for the transition to adulthood.     

Neurocognitive impairment in euthymic young adults with bipolar spectrum disorder and recurrent major depressive disorder

OBJECTIVE: Patients with remitted major depressive disorder (MDD) and bipolar disorder have persistent impairments in executive function and verbal memory that may represent endophenotypic abnormalities. In this study, we examine neurocognitive function in a sample of euthymic young adults with bipolar spectrum disorder (BSD) (Can J Psychiatry 2002; 47: 125-134) and compare this to well-matched samples of young adults with recurrent MDD and controls. METHOD: Twenty-one euthymic young adult patients with BSD were compared with 42 young adult patients with MDD and 33 controls on a neuropsychological battery assessing attention, executive function and verbal memory. RESULTS: Patients with BSD were significantly more impaired than MDD patients and controls on tests of executive function and verbal memory. MDD patients did not differ significantly from controls on verbal memory function but performed less well on a test of executive function. CONCLUSION: Euthymic young adults with BSD had greater impairment on neurocognitive measures associated with prefrontal and hippocampal function than MDD patients and controls. This is a reflection of a strong bipolar diathesis in the BSD group rather than being a consequence of a more severe unipolar illness.     

Functional impairment in the remission phase of bipolar disorder

OBJECTIVES: The purpose of this study was to evaluate functional impairment in a group of patients with bipolar disorder in remission and to determine the extent of relationships between overall functioning and current depressive, manic and panic spectrum symptoms. METHOD: A subset of the patient population at the Pittsburgh site of the Systematic Treatment Enhancement Program in Bipolar Disorder (STEP-BD) study was evaluated in this study. The subsample comprises 103 male and female subjects with bipolar I disorder (n = 70), bipolar II disorder (n = 24), schizoaffective disorder - bipolar type (n = 4), or bipolar disorder NOS (n = 5). Subjects were evaluated in a period of remission (at least 4 weeks with no more than two depressive or manic symptoms). Subjects were assessed for overall functional status using the Work and Social Adjustment Scale (WSAS) and for current bipolar and panic spectrum symptoms using the Mood Spectrum Self-Report questionnaire (MOODS-SR) and Panic-Agoraphobic Spectrum Self-Report questionnaire (PAS-SR). RESULTS: The median WSAS total score in these remitted subjects was 14, indicating significant functional impairment. Regressing WSAS on current depressive, manic, and panic spectrum total scores, we observed a highly significant depressive spectrum effect (t = 4.9, df = 94, p < 0.0001), but non-significant panic and manic spectrum effects (t = 1.3, df = 94, p = 0.19 and t = -1.8, df = 94, p = 0.07, respectively). CONCLUSION: Bipolar disorder is associated with functional deficits even during periods of sustained and substantial remission. The degree of functional impairment is correlated with the degree of depressive spectrum symptoms.