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PubMed2002

Cognitive functioning of long-term heavy cannabis users seeking treatment.

CONTEXT: Cognitive impairments are associated with long-term cannabis use, but the parameters of use that contribute to impairments and the nature and endurance of cognitive dysfunction remain uncertain. OBJECTIVE: To examine the effects of duration of cannabis use on specific areas of cognitive functioning among users seeking treatment for cannabis dependence. DESIGN, SETTING, AND PARTICIPANTS: Multisite retrospective cross-sectional neuropsychological study conducted in the United States (Seattle, Wash; Farmington, Conn; and Miami, Fla) between 1997 and 2000 among 102 near-daily cannabis users (51 long-term users: mean, 23.9 years of use; 51 shorter-term users: mean, 10.2 years of use) compared with 33 nonuser controls. MAIN OUTCOME MEASURES: Measures from 9 standard neuropsychological tests that assessed attention, memory, and executive functioning, and were administered prior to entry to a treatment program and following a median 17-hour abstinence. RESULTS: Long-term cannabis users performed significantly less well than shorter-term users and controls on tests of memory and attention. On the Rey Auditory Verbal Learning Test, long-term users recalled significantly fewer words than either shorter-term users (P =.001) or controls (P =.005); there was no difference between shorter-term users and controls. Long-term users showed impaired learning (P =.007), retention (P =.003), and retrieval (P =.002) compared with controls. Both user groups performed poorly on a time estimation task (P<.001 vs controls). Performance measures often correlated significantly with the duration of cannabis use, being worse with increasing years of use, but were unrelated to withdrawal symptoms and persisted after controlling for recent cannabis use and other drug use. CONCLUSIONS: These results confirm that long-term heavy cannabis users show impairments in memory and attention that endure beyond the period of intoxication and worsen with increasing years of regular cannabis use.

Adult↗

PubMed2005

Functional 3.0-T MR assessment of higher cognitive function: are there advantages over 1.5-T imaging?

PURPOSE: To compare cortical activation patterns associated with manual motor decision tasks at 1.5- and 3.0-T functional magnetic resonance (MR) imaging. MATERIALS AND METHODS: The local ethics committee approved this study, and informed written consent was obtained. Ten right-handed healthy volunteers (eight men and two women; mean age, 35 years +/- 7 [standard deviation]) underwent functional MR imaging twice, once at 1.5 T and once at 3.0 T, while performing cognitive tasks that demanded manual motor decisions (letter-finger matching and lexical and semantic decisions). While stimulus presentation was blocked, an event-related model was employed to analyze subjects' individual responses. A group analysis of functional data was performed with a t test of 1.5- and 3.0-T results in the 10 subjects. RESULTS: Manual motor decisions activated a widespread network of motor- (primary motor, posterior parietal) and decision-related areas (superior frontal cortex or anterior cingulate) at both field strengths (P <.05, corrected). Moreover, additional functional activation was detected in medial (supplementary motor area) and dorsal premotor regions (P <.05, corrected) at 3.0-T functional MR imaging, which was not detectable with corresponding 1.5-T imaging. The mean t value for peak voxels in activated areas detectable with both systems was 1.3 times larger at 3.0 T than that at 1.5 T. CONCLUSION: Functional 3.0-T MR imaging allows detection of additional activation in cortical areas involved in higher executive motor functions compared with functional 1.5-T MR imaging.

Adult↗

PubMed1988

Cannabis and cognitive functions: a prospective study.

Psychological tests measuring intelligence, memory and other cognitive functions were given to 26 heavy cannabis users (mean duration of cannabis use 6.76 years; average daily intake 150 mg THC). Compared with a control group, the cannabis users were found to react slowly in perceptuo-motor tasks, but not to differ in intelligence or memory tests. The users suffered disability in personal, social and vocational areas and indicated higher psychoticism and neuroticism scores.

Adolescent↗

PubMed2006

Cognitive functioning in orthostatic hypotension due to pure autonomic failure.

Psychophysiological science proposes close interactions between cognitive processes and autonomic responses, yet the consequences of autonomic failure on cognitive functioning have not been documented. This pilot study investigates, for the first time, the cognitive profile of 14 patients with Pure Autonomic Failure (PAF). Each patient was administered a comprehensive battery of neuropsychological tests and neuroimaging investigation. A number of patients (n = 6) presented with cognitive impairment. The two most frequent types of impairment were: deficits of speed and attention, and executive functioning. Impairments of free recall memory, intellectual functioning, nominal and calculation functions were also documented, albeit in a much lower frequency. These cognitive changes were not always associated with white matter abnormalities. We speculate that the cognitive impairments associated with PAF represent consequences of systemic hypotension with cerebral underperfusion. However, a failure in integrated bodily arousal responses during cognitive behaviours may also contribute to some of the observed deficits.

Aged↗

PubMed2003

Depression and cognitive functioning in alcoholism.

AIMS: Studies on cognitive processes in alcoholism have reported changes with respect to executive functions and memory, which have been interpreted within the context of different neuropsychological models. The aims of the present study were to investigate (1) the validity of these models and (2) the influence of depression on cognitive functioning in alcoholism. DESIGN, SETTING AND PARTICIPANTS: In the present investigation, patients suffering from alcoholism (Alc; n = 30), patients with depression but without alcoholism (Dep; n = 28) and healthy controls (HC; n = 28) were compared on a neuropsychological test battery. MEASUREMENTS: The test battery included measurements of mood, memory and executive functions. The possible cumulative effect of alcohol and depression was analysed by comparison of depressed alcoholic patients (Dalc) and non-depressed alcoholic patients (NDAlc). FINDINGS: Group comparisons revealed impairments of alcoholic patients with respect to response inhibition, reasoning and free recall, irrespective of depression. Priming, short-term memory as well as verbal fluency abilities were unaffected. Depressive patients showed verbal fluency as well as free recall deficits. However, there was no difference in performance between depressed and non-depressed alcoholics. CONCLUSIONS: The specific pattern of neuropsychological deficits of the alcoholic patients supports the frontal lobe hypothesis. The results of the present investigation suggest that these deficits are not generally exacerbated by comorbid depressive symptoms. Further studies, however, are desirable to investigate the relation between executive deficits and depression in alcoholics with evidence of major depression.

Adult↗

PubMed2006

PCBs and cognitive functioning of Mohawk adolescents.

This paper reports on the relationships between the cognitive functioning and PCB current body burdens of adolescents in the Mohawk Nation of Akwesasne where there is concern about industrial pollution of the environment. Three cognitive tests (Woodcock Johnson-Revised, Test of Memory and Learning, and Ravens Progressive Matrices) provide 13 subtests that allow a variety of cognitive outcomes to be assessed. A summary measure of PCB level was created from the congeners detected in at least 50% of the participants. The most notable finding was the significant negative relationship between PCB levels and two separate measures of long term memory. There was also a negative relationship with a measure of comprehension and knowledge. Significant relationships were not large, but provide evidence of subtle negative effects of PCB exposure.

Adolescent↗

PubMed1994

Neuropsychological correlates of central monoamine function in chronic schizophrenia: relationship between CSF metabolites and cognitive function.

Schizophrenia is associated with multiple cognitive deficits which in turn may be related to abnormal dopamine (DA) function. To examine possible associations between cognitive dysfunction and central DA activity in schizophrenia, neuropsychological measures (visuospatial and verbal recall; performance on the Wisconsin Card Sort Test (WCST); visuospatial perception) were examined in 17 drug-free male schizophrenic patients and related to cerebrospinal fluid concentrations of the metabolites of dopamine (homovanillic acid (HVA)), serotonin, and norepinephrine. CSF HVA concentrations were correlated with the ability to recall visuospatial information, with attention to verbal tasks, and with WCST performance (low CSF HVA concentrations predicting poor performance on these tests) but not with the ability to recall verbally presented material and visuospatial perception. These data are consistent with earlier results suggesting that (cortical) DA function is associated with recall and retrieval of visuospatial information and with WCST performance.

Adult↗

PubMed1991

Glycaemic thresholds for hypoglycaemic symptoms, impairment of cognitive function, and release of counterregulatory hormones in subjects with functional hypoglycaemia.

Nine patients with food-relieved hypoglycaemic symptoms, in whom insulinoma and other organic diseases presenting with hypoglycaemia had been ruled out, and nine matched controls, participated in the study. Subjects were studied during a 5-h controlled (Biostator) insulin-induced (1-2 mU kg-1 min-1) hypoglycaemic clamp. After 1 h of euglycaemia, we aimed to lower the glucose level in arterialized venous blood in a stepwise manner at 30-min intervals to 3.5, 3.0, and 2.0 mmol l-1, and to withhold these levels for a further 30 min. At euglycaemia and at the end of the latter steps, the visual reaction time and cognitive function (digit span, letter cancellation and trail making) were tested, together with recording symptoms and signs of hypoglycaemia. Counter-regulatory hormones were measured at 20-min intervals. In the patients, clinical signs and symptoms of hypoglycaemia developed at median blood glucose levels of 2.6-2.8 and 2.8-3.1 mmol l-1, respectively. By contrast, the blood glucose levels were 0.4-0.8 mmol l-1 lower in control subjects (P less than 0.05). Similarly, the median threshold for deterioration of visual reaction time was 2.8 mmol l-1 in patients and 2.1 mmol l-1 in controls (P less than 0.01). A similar trend was observed for the results of the neuropsychological tests. Visual reaction time deteriorated in all subjects, whereas the cognitive function of some of the subjects in each group remained unchanged during hypoglycaemia. The glycaemic thresholds for release of cortisol, glucagon and growth hormone were significantly higher in patients (P less than 0.05), whereas the thresholds for catecholamine release showed no significant difference from controls. Despite the comparable glucose infusion rates required to sustain each of the hypoglycaemic levels in the two groups, the control subjects achieved lower glucose levels, suggesting that there is resistance to insulin or glucose in functional hypoglycaemia. In conclusion, the present study suggests that the existence of a higher threshold for symptoms and signs, as well as for deterioration of brain function, may explain every-day hypoglycaemic symptoms, despite normal glucose levels, in subjects with functional hypoglycaemia. However, the hypothesis should be tested further using a blinded approach, including euglycaemic control studies.

Adult↗

PubMed2003

High-dose antioxidant supplements and cognitive function in community-dwelling elderly women.

BACKGROUND: Experimental data suggest that oxygen free radicals are probably involved in the deterioration of cognitive processes. OBJECTIVE: Our objective was to investigate the relation of high-dose antioxidant supplements to cognition. DESIGN: Information on the use of specific supplements containing vitamins E and C was collected biennially via mailed questionnaires beginning in 1980 from 14 968 community-dwelling women who participated in the Nurses' Health Study. From 1995 to 2000, telephone tests of cognitive function [Telephone Interview of Cognitive Status (TICS), delayed recall of the TICS 10-word list, immediate and delayed recall of a short paragraph, a test of verbal fluency, and a digit span backwards test] were administered to the women, who were 70-79 y of age at that time. We used linear and logistic regression models to calculate multivariate-adjusted mean differences in test scores and relative risks of a low score for specific supplement users compared with nonusers. RESULTS: Long-term, current users of vitamin E with vitamin C had significantly better mean performance, as judged by a global score that combined individual test scores, than did women who had never used vitamin E or C (P = 0.03); there was a trend for increasingly higher mean scores with increasing durations of use (P = 0.04). These associations were strongest among women with low dietary intakes of alpha-tocopherol. Benefits were less consistent for women taking vitamin E alone, with no evidence of higher scores with longer durations of use. Use of specific vitamin C supplements alone had little relation to performance on our cognitive tests. CONCLUSION: The use of specific vitamin E supplements, but not specific vitamin C supplements, may be related to modest cognitive benefits in older women.

Aged↗

PubMed2001

Cognitive function in euthymic bipolar I disorder.

Recent reports have suggested the presence of persistent cognitive impairments in patients diagnosed with Bipolar Disorder even after prolonged euthymic phases. In this work, various domains of cognitive function were examined in asymptomatic patients diagnosed with Bipolar I Disorder (BDI) in comparison with healthy subjects. Fifteen otherwise healthy BDI patients with a prior history of psychosis during mania completed a neuropsychological testing battery after a prolonged asymptomatic remission. Their scores were compared to those of individually matched healthy subjects with unpaired two-tailed t-tests at P<0.01. Relationships between cognitive performance measures and clinical variables related to illness severity were also examined with Pearson correlations, P<0.05. We detected poorer performance on measures of verbal learning, executive functioning and motor coordination in BDI patients compared to control volunteers. Scores on tests of executive functioning were negatively correlated with the number of episodes of mania and depression. Social and occupational scores were also associated with a poorer performance on measures of verbal learning and executive function. Euthymic BDI patients, therefore, demonstrate reductions in specific cognitive domains even after prolonged asymptomatic phases. Some of these deficits appear to be associated with a more severe course of illness and poorer social and occupational functioning.

Adult↗

PubMed1994

Cognitive function in depression: its relationship to the presence and severity of intellectual decline.

Cognitive dysfunction is an integral feature of depression, in some cases of sufficient severity to warrant a diagnosis of dementia. There has been little systematic investigation of whether cognitive dysfunction is an inevitable consequence of depression, or is specific to a subgroup of depressed patients. Related to this is the distribution of cognitive dysfunction, whether there is a continuum of impairment or a distinct demented subgroup. Finally, there is the question of which aspects of cognitive function are most sensitive to the intellectual decline seen in depression. A study is described which addresses these issues. The distribution of global cognition was found to be normally distributed in the sample of 29 patients assessed. Based on this distribution and the scores of a control sample, the patients were classified as unimpaired, borderline or impaired. Two sets of independent comparisons were carried out. First, the unimpaired depressed patients were compared to matched non-depressed controls. Significant deficits were found on a range of neuropsychological measures covering aspects of language function, memory, both recall and recognition, attention and behavioural regulation. These same patients were also compared with two groups of matched depressed patients, with varying degrees of global cognitive impairment. In general, the cognitive measures showed a gradient of dysfunction across the three patients groups. Significant differences between the depressed groups were shown on measures of immediate recall, attention and behavioural regulation. The possible significance of attentional factors for the observed memory dysfunction is discussed.

Adult↗

PubMed1986

Effect of naltrexone on mood and cognitive functioning among overweight men.

The effects of naltrexone on both mood and cognition were examined in overweight male subjects. Subjects were randomly prescribed, in a double-blind fashion, either placebo or naltrexone for 8 weeks. The results of the study showed that a chronic administration of a high dose of naltrexone (300 mg/day) does not significantly change mood or cognitive functioning among overweight adult men.

Adolescent↗

PubMed2000

Dosage of conventional neuroleptic medication and subjective cognitive functioning in schizophrenia.

Subjective cognitive and perceptual disturbances as assessed with the Frankfurt Complaint Questionnaire (FCQ) were correlated with chlorpromazine equivalents in 40 schizophrenic inpatients, who were treated with conventional neuroleptics. In line with previous research using 'objective' neuropsychological tests, both correlations and partial correlations (controlling for the effects of psychopathology, extrapyramidal symptoms and length of illness) confirmed that higher neuroleptic doses significantly worsen several cognitive and perceptual domains (r = 0.44 -0.54; P < or = 0.005 -0.05) with the possible exception of mnestic functions (r = 0.21 -0.24, n.s.) and language (r = 0.37 -0.38, P < 0.1). The clinical importance of self-report scales for evaluating both the risks and benefits of neuroleptic treatment is discussed.

Adult↗

PubMed1994

Contrasting infant predictors of later cognitive functioning.

The predictive power of early visual attention in terms of later cognitive functioning was compared to standard developmental test scores and further early predictors of later development. In a longitudinal study of 226 infants at risk visual attention in a habituation-dishabituation paradigm was assessed at 3 months and cognitive development was measured at 3, 24 and 54 months. The results indicated that response decrement and response recovery measures are related to cognitive outcome in later childhood, but failed to support their superiority over standard developmental test scores or early biological and psychosocial predictors of later IQ. Methodological shortcomings of previous studies and theoretical weaknesses of the habituation concept were discussed as a possible explanation.

Attention↗

PubMed1993

A longitudinal study of cognitive function in elderly persons with subjective memory complaints.

OBJECTIVE: To assess change in cognitive function in elderly individuals with subjective memory loss over a follow-up interval of more than 3 years. DESIGN: Prospective cohort study. SETTING: An outpatient research clinic in aging and dementia at a university hospital. PARTICIPANTS: A convenience sample of 59 healthy, elderly individuals (mean age 68.7 years) with memory complaints but no clinically apparent cognitive dysfunction. MEASUREMENTS: Participants were given a full diagnostic evaluation and were administered a neuropsychological test battery at baseline and follow-up. The cognitive assessment battery included 12 tests of recent memory, immediate memory, language function, visuospatial praxis, and psychomotor speed. Most of the tests had been established to be sensitive to cross-sectional age differences. RESULTS: Of 59 subjects, 54 (91.5%) were successfully followed up an average of 3.4 years later. Between baseline and follow-up, two tests exhibited significant improvement, two tests exhibited significant decline, and the other eight were unaffected. CONCLUSION: Elderly individuals with subjective perceptions of cognitive decrements who fail to provide clear evidence of cognitive impairment upon clinical interview are not at high risk for progressive cognitive deterioration over the subsequent 3- to 4-year interval.

Aged↗

PubMed1983

Cognitive functioning of alcoholic females: an exploratory study.

The effects of long-term alcoholism on the cognitive functioning of female alcoholics was examined through direct comparisons to equivalent male alcoholics and to both male and female controls on a battery of neuropsychological tests. As expected male alcoholics demonstrated deficits in abstraction, memory and visuoperceptual functioning whereas female alcoholics demonstrated deficits in abstraction and visuoperceptual functioning only. Apparently alcoholic females have fewer cognitive deficits than equivalent alcoholic males. Specifically after 30 days of sobriety alcoholic females were no different than control males or females on tests of memory whereas male alcoholic males were impaired. This finding if replicated implies the possibility of less structural brain damage in female alcoholics than equivalent alcoholics.

Adult↗

PubMed2003

A comparison of the effect of diphenhydramine and desloratadine on vigilance and cognitive function during treatment of ragweed-induced allergic rhinitis.

BACKGROUND: Decrements in cognitive performance are associated with the use of sedating antihistamines. Most, but not all, second-generation antihistamines have been found to be nonsedating. OBJECTIVE: To examine the central nervous system (CNS) profile of a new second-generation antihistamine, desloratadine. METHODS: Subjects with ragweed-induced allergic rhinitis (aged 18-60 years) who demonstrated a predetermined severity of symptoms after priming with ragweed pollen in the Environmental Exposure Unit were randomized to receive a single dose of desloratadine, 5 mg; diphenhydramine, 50 mg; or placebo. A comprehensive battery of repeatable, automated neuropsychological tests was administered to subjects before treatment (symptomatic baseline) and 90 minutes after taking study medication. RESULTS: Both desloratadine (P = .04) and diphenhydramine (P < .01) alleviated the symptoms of allergic rhinitis compared with placebo, but treatment with diphenhydramine was associated with clinically meaningful decrements on all vigilance parameters (P < .05 for desloratadine-diphenhydramine contrasts). Also, subjects treated with diphenhydramine performed significantly worse than subjects given desloratadine or placebo across all cognitive domains evaluated. Most effect sizes for the mean desloratadine and diphenhydramine differences were between 0.4 and 0.8 (moderate to high). Stanford Sleepiness Scale scores also indicated significantly more somnolence with diphenhydramine vs desloratadine or placebo (P < .001). There were no significant differences on any of the cognitive parameters between subjects treated with desloratadine and those given placebo. CONCLUSIONS: Desloratadine improved ragweed-induced allergic rhinitis symptoms without adversely affecting performance. Diphenhydramine improved allergic rhinitis symptoms but caused significant decrements in vigilance and cognitive functioning. Thus, efficacy of antihistamine treatment must be balanced against the associated effects on CNS functioning.

Allergens↗

PubMed1990

Cognitive function in Parkinson's disease: from description to theory.

From the large body of empirical evidence on cognitive function in Parkinson's disease, a number of attempts have been made to describe the characteristics of the deficits and the conditions under which they are observed. This review considers descriptions limited to specific domains of cognition such as visuospatial function, memory and 'frontal' function, and more general descriptions relating to 'set-shifting', sequencing, temporal ordering and recency discrimination, the locus of cognitive control and bradyphrenia. Later in the paper an attempt is made to provide some theoretical framework for the various descriptions. Two theories are discussed representing contrasting, but complementary approaches. The first is a 'psychological' theory in which the concept of depleted processing resources is suggested as a possible mechanism to explain the observable deficits. The second is a neurobiological model that attempts to integrate information from diverse sources to provide a model for the neuroanatomical and neurochemical substrate that may underlie some of the behavioural deficits.

Caudate Nucleus↗