Cocaine abuse among schizophrenic patients

Initial studies have indicated that stimulant abuse is prevalent among schizophrenic persons. To assess the phenomenon of cocaine abuse by patients with schizophrenia, 17 male cocaine-abusing schizophrenic patients were compared with 22 male schizophrenic patients who did not use cocaine. The cocaine-abusing subjects had been hospitalized more frequently, were more likely to be of the paranoid subtype, and were more likely to be depressed at the time of interview. It appears that cocaine abuse may influence both the psychopathologic presentation of schizophrenic patients and the intensity of care that they require.     

Learning and memory impairment in cocaine-dependent and comorbid schizophrenic patients

Impairments in verbal learning and memory functioning have been found to be cardinal features among individuals with schizophrenia as well as among non-schizophrenic cocaine abusers. Cognitive deficits in these areas, moreover, have been associated with poor treatment response and short-term outcome. Little is known, however, about the acute effects of cocaine abuse on schizophrenic patients' learning and memory functioning. Consequently, a potentially reversible and treatable source of cognitive impairment has been virtually ignored. The present study examined the extent of verbal learning and memory impairment in a group of cocaine-dependent schizophrenic patients (n=42) and a group of non-schizophrenic cocaine-dependent patients (n=21) within 72 h of the last cocaine use using the California Verbal Learning Test (CVLT). Schizophrenic patients (n=34) without any substance-use disorders were also tested in an identical time frame and served as a comparison group. Results revealed that all groups demonstrated significant learning and memory impairment relative to CVLT published age and gender corrected norms. Both cocaine-dependent and non-substance abusing schizophrenic groups presented a very similar pattern of impaired learning and recall performance across all CVLT task domains. Comorbid patients, in contrast, presented with marked deficits in their ability to learn and recall verbal information relative to either schizophrenic or cocaine-only groups. Moreover, the cocaine-abusing schizophrenic patients showed significant forgetfulness of the information that they did acquire during delayed recall conditions. The performance deficits exhibited by cocaine-abusing schizophrenic patients differed not only in relative severity of impairment, but also qualitatively in their increased rates of forgetfulness of acquired information. These results are interpreted in terms of the neurobiological substrates of learning and memory and the neurobiological impact of cocaine on schizophrenic patients' cognition during the early phase of inpatient hospitalization. These results suggest that comorbid patients should be targeted for specialized remediation efforts at the beginning phases of inpatient treatment.     

The neural correlates of cue-induced craving in cocaine-dependent women

OBJECTIVE: Drug use reminders are associated with localized changes in brain activity related to intense drug wanting or craving in cocaine-dependent men. While cocaine dependence is prevalent and disabling in women, and certain clinically relevant sex differences exist, there is an absence of knowledge related to the neural correlates of cocaine craving in cocaine-dependent women. METHOD: The differential neural response to imagery depicting cocaine use and neutral imagery was defined by using [15O]H2O positron emission tomography (PET) imaging in eight cocaine-dependent women. Results were compared with a matched group of eight cocaine-dependent men. RESULTS: Cocaine-related imagery was associated with relative increases in cocaine craving and increases in regional cerebral blood flow in the superior temporal gyrus, dorsal anterior and posterior cingulate cortex, nucleus accumbens area, and the central sulcus. Compared with the results of an identical PET study in matched cocaine-dependent men, conditioned cocaine craving in women was associated with less activation of the amygdala, insula, orbitofrontal cortex, and ventral cingulate cortex and greater activation of the central sulcus and widely distributed frontal cortical areas. CONCLUSIONS: These findings suggest the presence of sex differences in the functional anatomy of cue-induced cocaine craving associated with drug dependence. Such differences may reflect sex differences in conditioned associations to cocaine use, in affective and other corollaries of cocaine craving, or in their volitional regulation and may underlie apparent sex differences in the effects of cocaine abstinence and the expectations of treatment outcome. Some support for the need for sex-specific strategies for treatment of cocaine dependence is also furnished by the findings of this study.     

Lateralized attentional deficits in drug-free and medicated schizophrenic patients

Performance on a cued reaction time (RT) task, theoretically linked to posterior and anterior neuroanatomical systems in the brain (Posner, M. I. et al., Science, 1988, 210, 1627–1631; Archives of General Psychiatry, 1988, 15, 811–821), was used to assess sensory orienting and maintenance of attention. In schizophrenic patients, Posner et al. found a lateralized abnormality in RT (longer RTs to uncued targets in the right visual field than in the left visual field), as did Maruff et al. (Neuropsychologia, 1995, 33, 1205–1223), but Strauss et al. (Journal of Psychiatric Research, 1991, 37, 139–146), among others, did not replicate this effect. However, the subjects in these studies differed in the percentage of schizophrenic patients taking neuroleptic medication at the time of testing and in the chronicity of the illness. In the present study, we used two groups of schizophrenic subjects to control for the use of neuroleptic medication. The lateralized abnormality in RT was observed in the drug-free group of schizophrenic subjects, but not in the group of drug-treated schizophrenic subjects.     

精神分裂症患者父母的持续性注意功能

目的:探索精神分裂症患者父母的持续性注意功能特征。方法:对61例精神分裂症先证者(患者组),86名患者的父、母(父母组)以及64名正常对照者(对照组)进行持续性操作测验(CPT)检测。结果:在简单操作的反应时间分测验中,父母组的所有指标(舍弃数、漏答数、正确反应平均时间和变异系数)均高于对照组(P均<0.01),多数指标与患者组差异无显著性;但在复杂操作的X分测验中,父母组的多数指标均低于患者组(P均<0.01),而与对照组差异无显著性。无论是简单还是复杂操作中,患者组的所有指标均显著高于对照组(P均<0.01)。亲子间部分CPT指标均呈显著正相关(P<0.01~0·05)。结论:精神分裂症患者父母的CPT结果介于患者和正常对照者之间,简单操作中与患者组接近,复杂操作中与正常对照组相似。亲子间部分CPT指标呈显著正相关。提示持续性注意障碍有可能是该病内表型的一种标志。     

Cocaine abuse in schizophrenic patients treated with olanzapine versus haloperidol

Comorbid cocaine abuse adversely affects clinical outcomes in schizophrenia. Using a prospective, randomized, parallel group design (N = 24), we tested the hypothesis that patients with schizophrenia treated with olanzapine have reduced cocaine craving and abuse compared with those treated with haloperidol. In addition, we examined whether this differential effect correlated with reductions in extrapyramidal symptoms, positive and negative symptoms, and/or depression. There were no significant differences overall in proportions of positive drug screens between treatment groups; no differences in positive, negative, or depressive symptoms; and few differences between treatment conditions in extrapyramidal symptoms. However, craving for cocaine was rated significantly lower by patients treated with haloperidol compared with patients treated with olanzapine. Important study limitations include a small sample size and high attrition rates. Larger controlled studies are necessary to determine optimal antipsychotic therapy for patients with schizophrenia and comorbid cocaine abuse.     

The measurement of craving in cocaine patients using the Minnesota Cocaine Craving Scale

Drug craving is an irresistible urge that compels drug-seeking behavior, and which often accounts for relapse among treated cocaine users. A cocaine craving scale that has proven reliable and practical in clinical treatment research with cocaine-using subjects is presented. It assesses intensity, frequency, and duration of this entirely subjective phenomenon. Data from 234 scales completed by 35 patients in treatment showed that craving for cocaine was of variable intensity, experienced relatively few times per day (zero to two), and of short duration (less than 20 minutes). Internal consistency among the three scales was robust, shown by a standardized item alpha of .826. The use of this scale should allow for each component of craving to be studied separately.     

Perceptional and executive deficits of chronic schizophrenic patients in attentional and intentional tasks

The present study investigated whether schizophrenic patients could develop appropriate visual orientation and motor set under precuing conditions which contrasted attentional (input selective) and intentional (output selective) information. The aim was to evaluate perceptual performance in processing visuospatial information, and executive performance in response preparation. Stimuli and/or elicited responses were controlled for selective hemispheric engagement. Age, sex and handedness matched groups of 33 chronic schizophrenic patients and 33 normal subjects were tested on choice reaction time (RT) tasks in which warning signals were manipulated regarding either where a target stimulus would occur (selective attention) or which hand to use for responding (response preparation). All subjects benefited from precued information regarding subsequent responses. However, schizophrenic patients were not able to use intentional cues as effectively as control subjects did. Interhemispheric asymmetry of spatial attention was found in patients with schizophrenia, with slowing of responses to uncued targets presented in the right visual field. There was also a decreased advantage of within-hemisphere stimulus-response conditions in the schizophrenic group. Our results support the notion that a dysfunction involving parietal and premotor areas has potential importance in the schizophrenic illness. We replicated findings which indicate that deficits of information processing in schizophrenia may affect left hemispheric mechanisms to a larger extent. The results also point toward a possible abnormal connectivity between frontal and parietal circuits in schizophrenia.     

The effects of a visual search attentional bias modification paradigm on attentional bias in dysphoric individuals

Background and ObjectivesAttentional Bias Modification (ABM) may constitute a new type of treatment for affective disorders. ABM refers to computerized training programs that have been developed based on laboratory findings in experimental psychology. Meta-analyses have reported moderate effect sizes in anxiety disorders. Two small studies have also claimed an effect in dysphoria. Furthermore, a series of studies in individuals with low self-esteem has shown that they benefit from a single session of an ABM variant based on a visual search task. The current study tested the working mechanism of visual search ABM in dysphoria.MethodsForty dysphoric individuals engaged in a single session of ABM training or control training. Attentional bias for positive and negative facial expressions was assessed pre- and post training. Positive and negative mood states were assessed throughout the procedure.ResultsAttentional training had no effect on attentional bias. Positive and negative mood states were not differentially affected by training condition.LimitationsSmall treatment effects may have gone undetected and there are some methodological differences with prior research.ConclusionWe found no evidence that engaging in a single session of a visual search ABM modifies attentional biases for happy, sad or disgusted facial expressions.     

Cocaine Craving Questionnaire: assessing craving among cocaine users in Brazil

The Cocaine Craving Questionnaire was administered to 205 cocaine addicts. A 6/5 cut-off corresponded to the scale's best performance. Reliability was 0.803. Receiver Operating Characteristic analysis resulted in an area under the curve of 0.7199 +/- 0.0384, and dimensionality resulted in a three-factor solution. The scale is a reliable and valid instrument in identifying craving.     

A specific attentional bias in suicide attempters

Selective attention in patients after an attempted suicide was investigated to find out whether a specific attentional bias for suicide-related materials exists and to clarify the possible role of emotions in the bias. Thirty-one patients who had previously attempted to commit suicide and 31 control participants took part in a modified Stroop task. The suicidal patients took significantly longer to name the colors of suicide-related words compared with other words, whereas color naming times of the control participants did not differ for suicide-related, neutral, positive, or negative words. Therefore, the attentional bias exhibited by suicidal patients was highly specific. There was no relation between the bias and measures of anxiety, depression, or hopelessness, whereas suicidal ideation correlated significantly with the attentional bias.     

Attentional bias and attentional control in Posttraumatic Stress Disorder

Extensive evidence exists for an association between attentional bias (AB; attentional vigilance or avoidance) and anxiety. Recent studies in healthy participants suggest that attentional control (AC) may facilitate inhibition of automatic attentional processes associated with anxiety.To investigate relationships among AC, trauma-related AB, symptom severity and trait anxiety in patients with Posttraumatic Stress Disorder (PTSD), participants (N = 91) completed self-report measures of AC, posttraumatic stress symptoms (PTSS) and trait anxiety. AB was measured with a pictorial version of the Dot Probe Test.AC moderated the relationship between PTSS and AB (threat avoidance). Patients high in PTSS and low in AC showed attentional avoidance. No association between PTSS and AB in patients with medium or high levels of AC was found. A similar pattern of results was observed for the relationship between trait anxiety, AC and AB. These results suggest that a low ability to control attention is a risk factor for AB in PTSD. This first clinical study corroborates the accumulating evidence from analog studies that individual differences in top-down attentional control are of considerable importance in the expression of AB in anxious psychopathology.     

CSF CRH in abstinent cocaine-dependent patients

Alterations in stress responsivity may be important in the vulnerability to become cocaine dependent. Thus, an index of hypothalamic-pituitary-adrenal (HPA) axis function was examined in abstinent cocaine-dependent patients. Cerebrospinal fluid (CSF) concentrations of corticotropin releasing factor (CRH) were determined in 29 abstinent cocaine-dependent patients and 66 normal controls. The results showed that there was no significant difference between the abstinent cocaine-dependent patients and normal controls for CSF CRH. Also, CSF CRH concentrations were not related to cocaine-craving scores in a cue-elicited cocaine-craving procedure. Thus, these data suggest that after protracted abstinence from cocaine there is no marked dysregulation of CRH systems as measured by CSF CRH concentrations.     

盐酸氟西汀分散片对首发抑郁症患者注意偏倚的影响

目的 探讨首发抑郁症患者注意偏倚特点及盐酸氟西汀分散片对其注意偏倚的影响.方法 选择30例首发抑郁症患者作为实验组,对实验组治疗8周前后予不同情绪图片刺激的点探测任务测试.选择与实验组性别、年龄及文化程度相匹配的30例健康人作为对照组,比较反应时及注意偏向分的差异.结果 实验组平均反应时显著长于正常对照组(F=7.168,P=0.009),经过8周治疗后有明显的缩短(F=5.732,P=0.031),但比正常对照组长(F=5.194,P=0.036);实验组治疗前对负性情绪图片刺激的注意偏向分明显高于对正性刺激的注意偏向分(P=0.001),治疗8周后,该注意偏向分明显降低(P=0.012),但比正常对照组长(P=0.027).结论 抑郁症患者对负性情绪图片存在注意偏倚,盐酸氟西汀分散片对这种偏倚可能具有改善作用.     

难治性抑郁症患者无抽搐电休克治疗前后注意偏向的变化

目的:探讨难治性抑郁症患者注意偏向的特点及无抽搐电休克治疗(MECT)前后的变化。方法:对28例难治性抑郁症(研究组)患者在MECT前和MECT后2、4、6、8周进行情绪图片刺激的点探测任务测试,同时选择与研究组性别、年龄及文化程度相匹配的28名健康人作为对照组,比较研究组治疗前后以及与对照组之间反应时和注意偏向分的差异。结果:研究组的平均反应时尽管MECT后较MECT前有显著缩短(P<0.05),但始终长于对照组(P均<0.05)。研究组对负性情绪图片刺激的注意偏向分尽管在MECT后显著降低(P<0.05)且后4次测量结果之间差异无统计学意义(P>0.05),但仍明显高于对照组(P<0.05)。结论:难治性抑郁症患者对负性情绪图片存在注意偏向,MECT对这种偏向可能具有改善作用。     

Skin conductance responses to tones with and without attentional significance in schizophrenic and nonschizophrenic psychiatric patients

The skin conductance responses of schizophrenics with and without orienting responses to tones without attentional significance, were examined to the same tones with signal value, and randomly presented with non-signal or neutral tones. Most schizophrenics without orienting responses exhibited responses to signal tones and remained non-responders to neutral tones. Schizophrenics with orienting responses responded to both tones and their response rates were higher to neutral tones than non-schizophrenic patients. This is interpreted as evidence that schizophrenic responding and non-responding is not a function of frontal lobe involvement. Lateral asymmetry and group differences in response characteristics are reported.     

Amygdala activity correlates with attentional bias in PTSD

Post-traumatic stress disorder (PTSD) is an anxiety disorder arising in the aftermath of a traumatic event. The most prevalent hypothesis is that of an increased amygdala activity to threat cues. The amygdala has also shown an implication in orienting attention toward threat. The aim of the study was to explore the correlations between amygdala activity, symptom severity and attentional bias in PTSD. Patients and healthy controls were assayed on an fMRI emotional face matching task and an attentional detection of target (DOT) task. The amygdala showed enhanced activity in PTSD (vs. controls). It positively correlated with anxiety scores and PTSD symptomatology. It also positively correlated with the disengagement index. Mostly, these results provide preliminary support for an implication of the amygdala in attention orientation to threat in PTSD. These results are further discussed in light of recent theories concerned with cortico-limbic functioning.     

Eating disorders and attentional bias: a review

The cognitive model of eating disorders claims that eating disorder sufferers differ from other individuals with respect to the processing of food, body shape, and weight related stimuli. Employing tasks derived from experimental cognitive psychology, researchers have produced evidence to suggest that both anorexic and bulimic patients selectively attend to such stimuli. Despite the consistency of these findings, there are methodological problems that afflict this area of research and many unanswered questions. These issues are critically reviewed in the present paper.     

Smooth pursuit eye movements and neuropsychological tests in schizophrenic patients: Possible involvement of attentional components

The relationships among different components of frontal lobe dysfunction and voluntary attention were studied. Drug-free schizophrenic patients and matched normal controls were recruited and assessed for smooth pursuit eye movements, voluntary saccadic eye movements and by means of neuropsychological tests (Toluse-Pieron test and Wisconsin Card Sorting Test). No clear-cut relationship was found between eye movement performance and neuropsychological impairment.