Performance of schizophrenia and bipolar patients on verbal and figural working memory tasks.

Working memory (WM) was studied in 82 healthy volunteers, 43 schizophrenia patients, and 81 bipolar patients. Schizophrenia patients were impaired on verbal and figural WM tasks that possessed similar test discriminating power. Bipolar patients performed similarly to healthy volunteers. A mathematical model of WM performance revealed a primary role for reduced WM span in accounting for the impaired verbal WM of schizophrenia patients and a primary role for diminished attention in accounting for impaired figural WM. Although WM impairment in schizophrenia is due neither to the general effects of severe mental illness nor to the specific type of material studied, the microarchitecture of abnormal WM in schizophrenia may depend on the stimulus material presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modal attention asymmetry in patients with schizophrenia and bipolar disorder.

This cross-sectional study examined modal attention asymmetries in patients with schizophrenia (n?=?47) and bipolar disorder (n?=?42), as contrasted to a matched-sample comparison group of normal participants (n?=?89). A test of continuous auditory and visual attention was the primary measure. The data were analyzed from 2 experimental conditions: simple modal responses (auditory and visual) and modal switching responses (ipsimodal and cross-modal switching). In the simple modal condition, patients with schizophrenia demonstrated a visual over auditory asymmetry; patients with bipolar disorder showed no differences. In modal switching conditions, however, patients with bipolar disorder displayed a significant auditory over visual asymmetry. No main effect was detected between medications and attention functioning. Results are discussed in light of differentiating these 2 populations on the basis of modal specificity of attention functioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in neuropsychological performance and social functioning in schizophrenia and bipolar disorder.

Objective: To investigate sex differences in neurocognition and social functioning in schizophrenia and bipolar disorder and the possible role of sex as a moderator of this relationship. Method: Participants with schizophrenia (60 women/94 men), bipolar I disorder (55 women/51 men), and healthy controls (158 women/182 men) were assessed with an extensive neuropsychological test battery and a social functioning questionnaire. Results: We found significant main effects of sex for neuropsychological tests (p     

Effects of methylphenidate on discounting of delayed rewards in attention deficit/hyperactivity disorder.

Impulsivity is a central component of attention deficit/hyperactivity disorder (ADHD). Delay discounting, or a preference for smaller, immediate rewards over larger, delayed rewards, is considered an important aspect of impulsivity, and delay-related impulsivity has been emphasized in etiological models of ADHD. In this study, we examined whether stimulant medication, an effective treatment for ADHD, reduced discounting of delayed experiential and hypothetical rewards among 49 children (ages 9–12 years) with ADHD. After a practice day, participants completed a 3-day double-blind placebo-controlled acute medication assessment. Active doses were long-acting methylphenidate (Concerta), with the nearest equivalents of 0.3 and 0.6 mg/kg TID immediate-release methylphenidate. On each testing day, participants completed experiential (real-world money in real time) and hypothetical discounting tasks. Relative to placebo, methylphenidate reduced discounting of delayed experiential rewards but not hypothetical rewards. Broadly consistent with etiological models that emphasize delay-related impulsivity among children with ADHD, these findings provide initial evidence that stimulant medication reduces delay discounting among those with the disorder. The results also draw attention to task parameters that may influence the sensitivity of various delay discounting measures to medication effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Delay discounting of real and hypothetical rewards.

The degree to which real and hypothetical rewards were discounted across delays ranging from 6 hr to 1 year was explored in a within-subjects design. An adjusting-amounts procedure was used to estimate the subjective value of real and hypothetical rewards at each delay. A hyperbolic discounting function provided a significantly better fit to individual participants' preferences than did an exponential function. No significant effect of reward type on degree of hyperbolic discounting or area under the discounting curves was detected. These findings offer some support for the validity of using hypothetical rewards to estimate discounting rates in substance-abusing and other populations, but caution is suggested because this support is gleaned from a failure to detect an effect of reward type. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Are working memory deficits in bipolar disorder markers for psychosis?

Working memory deficits have been identified in bipolar disorder, but there is evidence suggesting that these deficits may be markers for psychosis rather than affective disorder. The current study examined this issue by comparing two groups of individuals with bipolar disorder, one with psychotic features and one without psychotic features, with a group of normal controls. Working memory was conceptualized as a multicomponent system that includes auditory and visuospatial short-term stores, executive control processes, and an episodic buffer that allows for communication between short- and long-term memory stores (Baddeley & Logie, 1999). Results indicated that only executive control processes significantly differentiated the psychotic and nonpsychotic bipolar groups, although visuospatial working memory differentiated both bipolar groups from controls. The results support the idea that some aspects of working memory performance are markers for psychosis, while others may be more general markers for bipolar disorders. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The impact of monetary reward on memory in schizophrenia spectrum disorder.

The impact of monetary reward on verbal working memory (vWM) and verbal long-term memory (vLTM) was evaluated in 50 patients with schizophrenia spectrum disorders and 52 matched healthy participants. This research was motivated by the observations that negative symptoms in schizophrenia are associated with reduced drive and that patients with these symptoms exhibit greater mnemonic impairments. Reward-related gains were evaluated across two levels of vWM load on the n-back task and across three aspects of vLTM derived from the California Verbal Learning Test-II (i.e., learning, total immediate recall, and retention). Although healthy individuals benefited from reward at a high vWM load level, schizophrenia patients exhibited no reward-related improvements in vWM. In contrast, improvement in vLTM retention was induced by reward for both patients and controls. Finally, symptomatic and pharmacology treatment factors were associated with reward-related gains in persons with schizophrenia. In conclusion, contingent monetary rewards delivered during vWM and vLTM enhanced specific aspects of memory. The influence was relatively small and dependent on the specific neurocognitive operation examined, the mental health status of the participants, and for patients, their particular symptoms and pharmacological treatments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thought suppression in patients with bipolar disorder.

Suppression of negative thoughts has been observed under experimental conditions among patients with major depressive disorder (MDD) but has never been examined among patients with bipolar disorder (BD). Patients with BD (n = 36), patients with MDD (n = 20), and healthy controls (n = 20) completed a task that required unscrambling 6-word strings into 5-word sentences, leaving out 1 word. The extra word allowed the sentences to be completed in a negative, neutral, or “hyperpositive” (manic/goal-oriented) way. Participants completed the sentences under conditions of cognitive load (rehearsing a 6-digit number), reward (a bell tone), load and reward, or neither load nor reward. We hypothesized that patients with BD would engage in more active suppression of negative and hyperpositive thoughts than would controls, as revealed by their unscrambling more word strings into negative or hyperpositive sentences. Under conditions of load or reward and in the absence of either load or reward, patients with BD unscrambled more negative sentences than did controls. Under conditions of reward, patients with BD unscrambled more negative sentences than did patients with MDD. Patients with BD also reported more use of negative thought suppression than did controls. These group differences in negative biases were no longer significant when current mood states were controlled. Finally, the groups did not differ in the proportion of hyperpositive sentence completions in any condition. Thought suppression may provide a critical locus for psychological interventions in BD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Family functioning and mood disorders: A comparison between patients with major depressive disorder and bipolar I disorder.

Within a sample of patients with major depressive disorder (MDD; n = 121) and bipolar affective disorder (BPAD; n = 69), the authors examined (a) diagnostic differences in family functioning at acute episode, (b) diagnostic differences in family functioning at episode recovery, (c) within-group changes in family functioning from acute episode to recovery, and (d) whether within-group changes from acute episode to recovery varied by diagnosis. Using a multidimensional model, the authors evaluated interviewer, patient, and family ratings. Overall, patients with MDD and BPAD evidenced similar levels of family impairment at acute episode and recovery. Generally, patients in both groups experienced improvement in family functioning over time, yet mean scores at recovery continued to range from fair to poor. Although certain specific differences emerged, diagnostic groups appeared to be more similar than different in level and pattern of family functioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Imagining the future: Degraded representations of future rewards and events in schizophrenia.

Over the course of life, most people work toward temporally distant rewards such as university degrees or work-related promotions. In contrast, many people with schizophrenia show deficits in behavior oriented toward long-term rewards, although they function adequately when rewards are more immediately present. Moreover, when asked about possible future events, individuals with schizophrenia show foreshortened future time perspectives relative to healthy individuals. Here, we take the view that these deficits are related and can be explained by cognitive deficits. We compared the performance of participants with schizophrenia (n = 39) and healthy participants (n = 25) on tasks measuring reward discounting and future event representations. Consistent with previous research, we found that relative to healthy participants, those with schizophrenia discounted the value of future rewards more steeply. Furthermore, when asked about future events, their responses were biased toward events in the near future, relative to healthy participants' responses. Although discounting and future representations were unrelated in healthy participants, we found significant correlations across the tasks among participants with schizophrenia, as well as correlations with cognitive variables and symptoms. Further analysis showed that statistically controlling working memory eliminated group differences in task performance. Together these results suggest that the motivational deficits characteristic of schizophrenia relate to cognitive deficits affecting the ability to represent and/or evaluate distant outcomes, a finding with important implications for promoting recovery from schizophrenia. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Verbal communication impairments and cognitive control components in people with schizophrenia.

Schizophrenia involves multiple communication impairments, including (a) disorganized speech, or formal thought disorder (FTD); and (b) decreased speech output, or poverty of speech. Both FTD and poverty of speech have been hypothesized to be associated with deficits in executive functioning or cognitive control. The current study examined whether FTD and poverty of speech were differentially associated with two distinct aspects of cognitive control, working memory and controlled retrieval. Compared with control participants (n = 30), people with schizophrenia (n = 47) exhibited poorer performance on both working memory and controlled retrieval tasks. However, only FTD (and not poverty of speech) was associated with poor working memory. In contrast, only poverty of speech (and not FTD) had a significant zero-order association with poor controlled retrieval. At the same time, working memory and controlled retrieval interacted to predict FTD, with the highest amount of FTD associated with both poor working memory and poor controlled retrieval. In contrast, psychometric control tasks were not associated with FTD or poverty of speech. This research suggests that FTD and poverty of speech are differentially associated with deficits in distinct aspects of cognitive control. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Predictors of relationship functioning for patients with bipolar disorder and their partners.

Previous investigations have examined family functioning, including marital functioning, as an important predictor of the course of bipolar disorder, but limited research exists identifying the factors that influence relationship functioning in patients with bipolar disorder. In the current study, 56 patients with bipolar disorder and their partners were assessed for Axis II pathology, general family functioning, and relationship distress. Patient mood symptoms and Axis II pathology variables were examined as predictors of general relationship functioning (Family Assessment Device, McMaster Clinical Rating Scale, and Dyadic Adjustment Scale) in regression models. Analyses indicated that patients' depressive symptomatology was associated with patient ratings of general family functioning and couple functioning, while patients' manic symptoms were associated with partners' ratings of the romantic relationship. Partners' total Axis II pathology, but not patients' Axis II pathology, was associated with patient and partner perception of the couple's relationship. These findings highlight the importance of mood and personality pathology to relationship functioning, and represent one of the first investigations to verify the impact of personality pathology on patients' and partners' perceptions of relationship functioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial and object working memory impairments in schizophrenia patients: A Bayesian item-response theory analysis.

This study reports evidence that schizophrenia patients are significantly impaired in both spatial and object (shape) working memory. A 3-s delay between exposure and recall of targets was used and Bayesian item-response theory was applied to compensate for the tasks' differential difficulty while simultaneously taking account of missing data from participant attrition. Weaker evidence was found that in schizophrenia both domains are equally impaired on average, that spatial and object working memory appear to be more highly correlated with each other in the schizophrenia population than in the normal population, and that schizophrenia patients show greater variability in spatial than in object working memory performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anhedonia and the experience of emotion in individuals with schizophrenia.

Research shows that individuals with schizophrenia report symptoms of anhedonia when assessed by interview or questionnaire. However, when presented with emotional stimuli, they report emotional experiences that are similar to those of control participants. The authors hypothesized that deficits in working memory and episodic memory contribute to such discrepancies. They administered measures of working and episodic memory, self-report anhedonia questionnaires, and several types of emotional stimuli to 49 individuals with schizophrenia and 47 control participants. All participants reported experiencing similar amounts of pleasant-unpleasant emotion (valence) in response to stimuli, but individuals with schizophrenia reported experiencing less arousal for negative stimuli. Individuals with schizophrenia also reported greater social and physical anhedonia on a traditional anhedonia questionnaire. Disturbances in working memory moderated the relationship between physical anhedonia and participants' emotional experience of positive stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Delay discounting in current and former marijuana-dependent individuals.

Studies have found that a variety of drug-dependent groups discount delayed rewards more than matched controls. This study compared delay discounting for a hypothetical $1,000 reward among dependent marijuana users, former dependent marijuana users, and matched controls. Discounting of marijuana was also assessed in the currently marijuana-dependent group. No significant differences in discounting were detected among the groups; however, currently dependent users showed a trend to discount money more than the other 2 groups. Within the dependent marijuana group, marijuana was discounted more than money, and discounting for money and marijuana was significantly and positively correlated. Regression analyses indicated that delay discounting was more closely associated with tobacco use than marijuana use. A variety of questionnaires were also administered, including impulsivity questionnaires. Dependent marijuana users scored as significantly more impulsive on the Impulsiveness subscale of the Eysenck Impulsiveness–Venturesomeness–Empathy questionnaire than controls. However, the 3 groups did not significantly differ on several other personality questionnaires, including the Barratt Impulsivity Scale—11. The Stanford Time Perception Inventory Present–Fatalistic subscale was positively correlated with money and marijuana discounting, indicating that a greater sense of powerlessness over the future is related to greater delay discounting. Results suggest that current marijuana dependence may be associated with a trend toward increased delay discounting, but this effect size appears to be smaller for marijuana than for previously examined drugs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Family functioning among adolescents with bipolar disorder.

This study examined the characteristics of families of adolescents with bipolar disorder during or shortly following a period of mood exacerbation, using measures of family conflict, cohesion, adaptability, and expressed emotion (EE). Demographic, diagnostic, and family functioning data were collected from 58 families (mean age = 14.48; 33 female, 25 male) before entering a randomized trial of family focused treatment. Compared to scale scores reported by healthy adolescents and their families, cohesion and adaptability were more impaired in families with an adolescent with bipolar disorder. Levels of conflict, while higher than normative scores reported by healthy families, were not significantly different from scores gathered from distressed, clinic-referred families. Parents rated high in EE reported less cohesion and adaptability, and more conflict, than parents rated low in EE. Parents expressing greater numbers of critical comments also reported more conflict than those who expressed fewer criticisms. These EE group differences were not accounted for by concurrent adolescent symptom levels. Family adaptability, cohesion, and conflict may be important targets for family treatments administered during the postepisode phases of early onset bipolar disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

From A to Z on child and adolescent bipolar disorder.

Reviews Bipolar disorder in childhood and early adolescence (2003), edited by Barbara Geller and Melissa P. DelBello (see record 2003-04754-000). This book is structured to offer a well-rounded account of issues surrounding childhood and adolescent bipolar disorder. This volume is seen as a much needed desk reference for seasoned mental health and medical professionals as well as those in graduate level training programs. Geller and DelBello have organized a comprehensive and rigorous review of the current knowledge base, scientific innovation and technology, and future direction of assessment and treatments for childhood bipolar disorder. This book serves as a superb resource for professionals who treat families with bipolar children and as a catalyst for future debate, research, and innovation. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Observed emotional involvement and overinvolvement in families of patients with bipolar disorder.

Many studies have examined the construct validity of the criticism component of expressed emotion, but little work has been done on clarifying the emotional overinvolvement (EOI) construct. In a sample of 115 recently episodic patients with bipolar disorder, the authors of the present study examined the construct validity of an observational coding system for both appropriate and inappropriate emotional involvement that permitted separate ratings for relatives' intrusiveness, self-sacrificing behaviors, and distress related to the patient's well-being. Findings support the measure's reliability and convergent validity and are moderately supportive of the measure's discriminant validity. Results also suggest that Camberwell Family Interview (C. E. Vaughn & J. P. Leff, 1976) EOI ratings do not discriminate among the different dimensions of the emotional involvement construct (or their appropriateness or inappropriateness) as revealed in laboratory-based interactions. The findings suggest that clinicians working with such families might consider differentiating among the various ways in which family members are involved with the patient and helping them learn to judge under what circumstances such involvement is appropriate and inappropriate. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impulsivity and rapid discounting of delayed hypothetical rewards in cocaine-dependent individuals.

In this study, crack/cocaine-dependent (CD) and non-drug-using matched control (MC) participants were presented with hypothetical immediate and delayed rewards, with 16 delay conditions ranging from 5 min to 25 years. All participants were presented with hypothetical monetary rewards; however, the CD group was also presented with hypothetical crack/ cocaine rewards. The objective value of the rewards ranged from $1 to $1,000. Hyperbolic discounting functions provided a good fit of the data. The CD group discounted monetary rewards at a higher rate than the MC group did, and the CD group discounted crack/cocaine rewards at a higher rate than it did monetary rewards. Moreover, scores on self-report measures indicated greater impulsivity in the CD group when compared with the MC group. (PsycINFO Database Record (c) 2010 APA, all rights reserved)