Changes in cocaine consumption are associated with fluctuations in self-reported impulsivity and gambling decision-making

BACKGROUND

In cross-sectional studies, cocaine users generally display elevated levels of self-reported and cognitive impulsivity. To what extent these impairments are stable v. variable markers of cocaine use disorder, and, thus, are pre-existing or drug-induced, has not yet been systematically investigated.

METHOD

We conducted a longitudinal study with cocaine users who changed or maintained their consumption intensity, measuring self-reported impulsivity with the Barratt Impulsiveness Scale (BIS-11), and cognitive impulsivity with the Rapid Visual Processing task (RVP), Iowa Gambling task (IGT), and Delay Discounting task (DD) at baseline and at 1-year follow-up. We assessed 48 psychostimulant-naive controls and 19 cocaine users with decreased, 19 users with increased, and 19 users with unchanged cocaine intake after 1 year as confirmed by hair analysis.

RESULTS

Results of linear multilevel modelling showed significant group × time interactions for the BIS-11 total score and the IGT total card ratio. Increasers showed a trend for elevated scores, whereas decreasers exhibited reduced self-reported impulsivity scores within 1 year. Surprisingly, increasers' IGT performance was improved after 1 year, whereas decreasers' performance deteriorated. By contrast, neither RVP response bias B" nor DD total score showed substantial group × time interactions. Importantly, BIS-11 and DD revealed strong test-retest reliabilities.

CONCLUSION

Self-reported impulsivity (BIS-11) and decision-making impulsivity (IGT) covary with changing cocaine use, whereas response bias and delay discounting remain largely unaffected. Thus, self-reported impulsivity and gambling decision-making were strongly state-dependent in a stimulant-using population and may be suitable to monitor treatment success, whereas delay of gratification was confirmed as a potential endophenotype of stimulant addiction.

The role played by depression associated with somatic symptomatology in accounting for the gender difference in the prevalence of depression

PURPOSE

A variety of studies suggest the existence of a distinct phenotype of somatic depression, i.e., depression accompanied by significant somatic symptomatology. Previous research suggests that the gender difference in the prevalence of depression is primarily due to a difference in somatic depression. The aim of this study was to compare the gender difference in the prevalence of somatic depression and of depression not accompanied by significant somatic symptomatology (labelled "pure" depression) in two representative samples, the National Comorbidity Survey-Replication (NCS-R) and the Zurich Study.

METHOD

The gender difference in lifetime somatic depression was compared to that of pure depression based on analyses weighted back to the general population in two representative samples. The NCS-R analyses involved a narrow definition of somatic depression with items from the DSM criteria for depression--appetite, sleep, and fatigue. The analysis of the Zurich study added headaches, body image issues, and breathing difficulties to the criteria and comparison to atypical depression.

RESULTS

In both samples, the gender difference in depressive prevalence was due to a large difference in somatic depression with other phenotypes showing little or no gender difference. The gender differences were found to be due to the somatic symptoms rather than the number of symptoms and were much larger for somatic than for atypical depression.

CONCLUSION

The gender difference in the prevalence of depression results from the higher prevalence among women of a specific phenotype, somatic depression.

Subjective distress predicts treatment seeking for depression, bipolar, anxiety, panic, neurasthenia and insomnia severity spectra

OBJECTIVE

To examine correlates of mental health treatment seeking such as gender, diagnosis, impairment, distress and mastery.

METHOD

Longitudinal epidemiological data from the Zurich Study of common psychiatric syndromes, including unipolar and bipolar depression, panic, anxiety, neurasthenia and insomnia, were utilized. In longitudinal Generalized Estimating Equations, treatment seeking was regressed on measures of subjective distress and impairment, childhood family problems, mastery and number of comorbid diagnoses.

RESULTS

Approximately half of all treated participants across all six syndromes suffered from subthreshold disorders. Meeting full or subthreshold diagnostic criteria was associated with treatment seeking for insomnia. Being female was associated with treatment seeking for depression. The only variable highly and consistently associated with treatment seeking, across all syndromes, was subjective distress. Treated participants reported high levels of distress, work and social impairment in both diagnostic and subthreshold groups.

CONCLUSION

Subjective distress may be a better indicator of treatment seeking than symptom count.

Impact of Childhood Adversity and Premorbid Personality on the Onset and Course of Major Bipolar Disorder

Background:

Clinical studies have demonstrated the great clinical relevance of long-term depression (LTD). Our study aims to characterise long-term bipolar disorder (LTBP) in comparison with episodic (non-chronic) bipolar major depressive episodes (EBP) on the basis of data from a community sample.

Method:

The Zurich Cohort Study is a prospective study of young adults followed from age 20/21 to 40/41 with six interviews. The stratified sample consisted of two thirds high scorers and one third lower scorers on the Symptom Checklist-90 R (SCL-90-R). LTBP, which was assessed from age 27/28 to 40/41, was defined as threshold or subthreshold depressive syndrome plus hypomanic symptoms, present for more days than not over the past year, plus work or social impairment.

Results:

The cumulative incidence of LTBP was 6.3%, and of episodic BP 15.3%. The two groups did not differ in mean age of onset (13.7 vs. 13.1 years). Age of onset was significantly earlier in subjects with a positive FH of depression and was inversely correlated with the somatisation score of the SCL-90R as assessed at age 19/20. The age of onset increased with increasing levels of childhood family problems in subjects with a positive FH, but decreased in subjects without an FH of depression. Chronic BP was associated with early childhood adversity and low self-esteem and, at a trend-level, with no family history of depression.

Conclusions:

The results are surprising and counter-intuitive, a genetic disposition seeming to be correlated more with periodicity than with chronicity.

Parsing the clinical phenotype of depression: the need to integrate brief depressive episodes

OBJECTIVE

To expand the concept of recurrent brief depression (RBD) to brief depression (BD) and to test its clinical relevance.

METHOD

Subjects (N = 591) were studied prospectively six times from ages 20/21 to 40/41 years. RBD was defined according to DSM-IV as episodes under 2 weeks with about monthly recurrence and work impairment. BD embraces RBD and brief depressive episodes with a frequency of 1-11 per year.

RESULTS

Pure BD and pure major depressive episodes (MDE) did not differ in treatment rates, family history of mood and anxiety disorders or comorbidity with bipolar spectrum and anxiety disorders but they differed in work impairment, suicide attempt rates and distress self-ratings. The combination of BD + MDE identified a very severe group of MDE, comparable with combined depression (MDE + RBD) and double depression (MDE + dysthymia).

CONCLUSION

Our data argue for the use of BD as a diagnostic specifier for severe MDE. RBD remains an important independent subgroup.

Melancholia and atypical depression in the Zurich study: epidemiology, clinical characteristics, course, comorbidity and personality

OBJECTIVE

A comparison of psychiatric, psychological and somatic characteristics in specified subgroups of major depressive episodes (MDE).

METHOD

In a stratified community sample of young adults investigated prospectively from age 20/21 to 40/41, we defined four MDE subgroups: i) DSM-IV melancholia or atypical depression (the 'combined group'), ii) pure melancholia, iii) pure atypical depression, and iv) unspecified MDE.

RESULTS

The cumulative incidence rates of the four groups were 4.1%, 7.1%, 3.5% and 8.2% respectively. Women were over-represented in the combined and atypically depressed group. In 56 of 117 (47.9%) cases, melancholia was longitudinally associated with atypical MDE (n = 84) (OR = 11.9).

CONCLUSION

Melancholic MDE was more severe than atypical MDE although the two groups shared many characteristics. The longitudinal overlap of melancholia with atypical depression in almost half of all cases calls for comparative analyses of combined, pure and unspecified MDE.

Asthma and body weight change: a 20-year prospective community study of young adults

OBJECTIVE

There is increasing evidence for an association between asthma and body weight change. The objectives of these analyses were to examine the temporal relationships of this association and to explore the role of childhood depression as an explanatory factor.

METHODS

Data were derived from six subsequent semistructured interviews on health habits and health conditions from a single-age community study of 591 young adults followed up between ages 20 and 40 years.

RESULTS

Cross-sectionally (over the whole study period), asthma was significantly associated with obesity (odds ratio=3.9 [95% confidence interval 1.2, 12.2]). Multivariate longitudinal analyses revealed that asthma was associated with increased later weight gain and later obesity among women after controlling for potentially confounding variables, whereas weight gain and obesity were not associated with later asthma. A secondary analysis showed that depressive symptoms during childhood were associated with adult obesity and asthma, partially explaining the asthma-obesity comorbidity.

CONCLUSION

This study encourages further research on mechanisms underlying the asthma-obesity comorbidity, particularly on shared psychosocial factors operating during critical periods in childhood and adolescence that may influence the development and persistence of both obesity and asthma during adulthood.

Depressive symptoms during childhood and adult obesity: the Zurich Cohort Study

Depression and obesity have become major health problems with increasing prevalence. Given the limited effectiveness of treatment for weight problems, the identification of novel, potentially modifiable risk factors may provide insights on new preventive approaches to obesity. The purpose of this study was to test the hypothesis that depressive symptoms during childhood are associated with weight gain and obesity during young adulthood. Participants were from a prospective community-based cohort study of young adults (N=591) followed between ages 19 and 40 years. The sample was stratified to increase the probability of somatic and psychological syndromes. Information was derived from six subsequent semistructured diagnostic interviews conducted by professionals over 20 years. The outcome measures were body mass index (BMI) and obesity (BMI>30). Among women, depressive symptoms before age 17 years were associated with increased weight gain (4.8 vs 2.6% BMI increase per 10 years) representing greater risk for adult obesity (hazard ratio=11.52, P<0.05). Among men, only after controlling for confounders, depressive symptoms before age 17 years were associated with increased weight gain (6.6 vs 5.2% BMI increase per 10 years) in adulthood but not with occurrence of obesity. These associations between childhood depressive symptoms and adult body weight were adjusted for baseline body weight, a family history of weight problems, levels of physical activity, consumption of alcohol and nicotine, and demographic variables. As the magnitude of the associations was high, and depression during childhood is a prevalent and treatable condition, this finding may have important clinical implications for the prevention and treatment of obesity. Whether the results of this study are limited to populations with elevated levels of psychopathology remains to be tested.

Nosology and treatment of primary headache in a Swiss headache clinic

We assessed demographics, diagnoses, course, severity, impact and treatment of primary headache outpatients from records in the Headache and Pain Clinic, Neurological Department, Zürich University Hospital. All outpatients seen from 1996 to 1998 for migraine, tension–type headache, and both, were included. Diagnoses, drug, physical and alternative treatments before and after referral were listed. Descriptive statistics were used for differences between the general population and this sample, the diagnoses, and treatments. The coexistence of migraine and tension–type headache, and the high frequencies of headache days would have excluded most migraine patients from typical drug trials: at best, only one third were eligible. The socioeconomic impact of combined and difficult syndromes calls for comprehensive management beyond simple treatment with instant relief drugs. The diagnostic and therapeutic practices of referring physicians exposed a deficit of information on headache, and a need for relevant education.

The associations between psychopathology and being overweight: a 20-year prospective study

BACKGROUND

Psychiatric disorders and being overweight are major health problems with increasing prevalence. The purpose of this study was to test the hypothesis that being overweight is associated with a range of psychiatric conditions including minor and atypical depressive disorders, binge eating, and aggression.

METHOD

Prospective community-based cohort study of young adults (n = 591) followed between ages 19 and 40. Information derived from six subsequent semi-structured diagnostic interviews conducted by professionals over twenty years. Outcomes were being overweight [body-mass index (BMI)> 25] and average yearly weight change between ages 20 and 40 (BMI slope).

RESULTS

18.9 % of the participants were classified as being overweight. Being overweight turned out to be a stable trait: 77.7% of subjects were assigned to the same weight class at each interview. Atypical depression and binge eating were positively associated with both, increased weight gain and being overweight, while psychiatric conditions associated with aggressive behaviors (aggressive personality traits, sociopathy) were positively associated with being overweight, but were not related to the rate of weight change. Generalized anxiety disorder was negatively associated with overweight. These results persisted after controlling for substance use, levels of physical activity, demographic variables and family history of weight problems.

CONCLUSIONS

This study shows relatively strong associations between eating-related and aggressive psychopathology and being overweight. Given the high prevalence rates of these conditions, this study encourages further research on the causality of psychopathology-overweight associations that might provide insight on novel preventive approaches for major health problems.

Risk factors for the bipolar and depression spectra

OBJECTIVE

To identify risk factors for mood disorders in a community sample studied from the ages of 20 to 35 years.

METHOD

Social characteristics, a family history of mood disorders and some personality features were analysed as risk factors for bipolar and depressive disorders by means of logistic regression.

RESULTS

Frequent 'ups and downs' of mood were the strongest risk factor for both bipolar and depressive disorders; a weaker risk factor for both was emotional/vegetative lability (neuroticism). An additional risk factor for bipolar disorders was a positive family history of mania, whereas for depression it was a positive family history of depression/fatigue. As a risk factor for bipolar disorders, 'ups and downs' were much stronger than a positive family history of mania. Frequent ups and downs were independent of the family history of mood disorders.

CONCLUSION

The results suggest that mood regulation should be investigated as a new, very important independent risk factor for mood disorders.

The Zurich Study: participation patterns and Symptom Checklist 90-R scores in six interviews, 1979-99

OBJECTIVE

The Zurich study is a longitudinal study in psychiatric epidemiology that started in the late 1970s. The sixth interview in 1999 provides the basis to investigate and update the participation and drop-out patterns of the Zurich subjects.

METHOD

Aside from descriptive analyses, particular attention was paid to the Symptom Checklist 90-R (SCL-90-R), used initially to stratify the Zurich sample.

RESULTS

The initial proportions of high-scorers vs. low-scorers (two-thirds vs. one-third) have not changed significantly in the 367 subjects who participated in the 1999 interview. More detailed analyses indicate a selective and changing dependence of participation/drop-out on health status as measured by the SCL-90 R. In recent interviews drop-out has become more likely in subjects with extremely high SCL scores and in subjects with low SCL scores.

CONCLUSION

Drop-out in the Zurich Study is associated with extreme SCL scores.

Gender differences in depression. Epidemiological findings from the European DEPRES I and II studies

BACKGROUND

While there is ample evidence that the prevalence rates for major depressive disorder (MDD) in the general population are higher in women than in men, there is little data on gender differences as regard to symptoms, causal attribution, help-seeking, coping, or the consequences of depression.

METHOD

The large DEPRES Study dataset covering representative population samples of six European countries (wave I: 38,434 men and 40,024 women; wave II: 563 men and 1321 women treated for depression) was analyzed for gender differences.

RESULTS

In wave I marked gender differences were found in the six-month prevalence rate for major depression but less so for minor depression; the gender differences for major depression persisted across all age groups. Even after stratification by clinically significant impairment and paid employment status, men reported fewer symptoms than women; as a consequence, men reached the diagnostic threshold less often. In wave II there were clear gender differences in causal attribution and in coping. Men coped by increasing their sports activity and consumption of alcohol and women through emotional release and religion. Women felt the effects of depression in their quality of sleep and general health, whereas men felt it more in their ability to work.

LIMITATIONS

The second wave of the study comprises treated depressives only and may be less representative than the first wave.

Gender differences in the subjective effects of MDMA

RATIONALE

3.4-Methylenedioxymethamphetamine (MDMA) mainly releases serotonin (5-HT) and is contained in the recreational drug Ecstasy. 5-HT is known to play an important role in mood and anxiety disorders, for which there is a female preponderance. To date, there are no systematic data on gender differences in the subjective effects of MDMA.

OBJECTIVES

The present work analyzed the pooled data from three controlled studies on the psychological and physiological effects of MDMA in healthy volunteers with no or minimal MDMA experience. A particular focus of the analyses were possible gender differences.

METHODS

A total of 74 subjects (54 male, 20 female) participated in all three studies. MDMA in oral doses ranging from 70-150 mg (1.35-1.8 mg/kg) was administered under double-blind placebo-controlled conditions. Subjective peak changes were assessed by standardized psychometric rating scales. Physiological measures were blood pressure, heart rate, and peripheral body temperature. Adverse drug effects were assessed during the experimental session and after 24 h.

RESULTS

Psychoactive effects of MDMA were more intense in women than in men. Women especially had higher scores for MDMA-induced perceptual changes, thought disturbances, and fear of loss of body control. The dose of MDMA positively correlated with the intensity of perceptual changes in women. Acute adverse effects and sequelae were also more frequent in female than in male subjects. In contrast, men showed higher increases in blood pressure than woman.

CONCLUSIONS

The fact that equal doses of MDMA per kilogram body weight produce stronger responses in women compared to men is consistent with an increased susceptibility of women to the 5-HT-releasing effects of MDMA. Our results also indicate that increasing doses of MDMA produce more hallucinogen-like perceptual alterations, particularly in women.

No difference in brain activation during cognitive performance between ecstasy (3,4-methylenedioxymethamphetamine) users and control subjects: a [H2(15)O]-positron emission tomography study

The long-term use of the serotonin-releaser and uptake-inhibitor 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy") has been associated with memory impairments and increased liability to depressive mood and anxiety attacks. It is unclear, however, whether these psychologic deviations are reflected in alterations of the underlying neurophysiologic substrate. The authors compared mood and regional cerebral blood flow (rCBF) profiles between regular polytoxic Ecstasy users and Ecstasy-naive controls. Brain activity as indexed by rCBF was measured during cognitive activation by an attentional task using positron emission tomography and [H2(15)O]. Mood was assessed by means of the Hamilton Rating Scale for Depression (HAM-D) and the EWL Mood Rating Scale. Statistical parametric mapping revealed that brain activity did not differ between the two groups. Both groups also performed equally on the cognitive task requiring sustained attention. However, significantly higher levels of depressiveness as determined by the HAM-D and EWL scales were found in Ecstasy-using subjects. These data indicate that, despite differences in mood, polytoxic Ecstasy users do not differ from Ecstasy-naive controls in terms of local brain activity. Heightened depressiveness in the Ecstasy group was consistent with results from previous studies and could be related to serotonergic hypofunction resulting from repeated MDMA consumption. However, this study cannot exclude the possibility that the observed differences are preexisting rather than a result of Ecstasy use.

Concurrent psychiatric comorbidity and multimorbidity in a community study: gender differences and quality of life

This study analysis of a community cohort at the age of 35 focused on the effects of gender and multimorbidity on quality of life and subjective distress. Consistent with an earlier analysis, quality of life decreased with increasing numbers of concurrent psychiatric diagnoses. Women generally reported lower quality of life and higher distress than men. Relative to men, well-being in women was subject to more diagnostic (alcohol abuse/dependence, depression, generalized anxiety disorder, bulimia) and social influences (partner, promotion). The same factors predicted women's psychological and physical well-being, indicating a more holistic experience in women. Men's physical well-being did not correlate with any of the diagnostic or social variables measured.

3,4-Methylenedioxymethamphetamine (MDMA) modulates cortical and limbic brain activity as measured by [H(2)(15)O]-PET in healthy humans

[H(2)(15)O]-Positron Emission Tomography (PET) was used to examine regional cerebral blood flow (rCBF) after administration of a single oral dose of the serotonin realeaser and uptake inhibitor MDMA (1.7 mg/kg) or placebo to 16 MDMA-naïve subjects. Psychological changes were assessed by psychometric rating scales. MDMA produced distributed changes in regional blood flow including increases in ventromedial frontal and occipital cortex, inferior temporal lobe and cerebellum; and decreases in the motor and somatosensory cortex, temporal lobe including left amygdala, cingulate cortex, insula and thalamus. Concomitant with these changes, subjects experienced heightened mood, increased extroversion, slight derealization and mild perceptual alterations. MDMA also produced increases in blood pressure and several side effects such as jaw clenching, lack of appetite and difficulty concentrating. These results indicate that a distributed cluster of brain areas underlie the various effects of MDMA in humans.

Psychological and physiological effects of MDMA ("Ecstasy") after pretreatment with the 5-HT(2) antagonist ketanserin in healthy humans

MDMA (3,4-methylenedioxymethamphetamine, "Ecstasy") mainly releases serotonin and dopamine. In animals, pretreatment with 5-HT(2) antagonists has been shown to attenuate neurochemical and behavioral effects of MDMA. In humans, the role of 5-HT(2) receptors in the action of MDMA has not been studied. We investigated the effect of pretreatment with the 5-HT(2A/C) antagonist ketanserin (50 mg p.o.) on subjective responses to MDMA (1.5 mg/kg p.o.) in 14 healthy volunteers using a double-blind placebo-controlled within-subject design. Subjective effects were rated by psychometric rating scales. Physiological effects measured were blood pressure, heart rate, and body temperature. Adverse effects were assessed during the sessions, and after one and three days. Ketanserin attenuated MDMA-induced perceptual changes, emotional excitation, and acute adverse responses but had little effect on MDMA-induced positive mood, well-being, extroversion, and short-term sequelae. Body temperature was lower under MDMA plus ketanserin compared to MDMA alone. The results suggest a contributing role for 5-HT(2) receptors in the action of MDMA in humans.

Acute psychological effects of 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy") are attenuated by the serotonin uptake inhibitor citalopram

3,4-Methylenedioxymethamphetamine (MDMA, "Ecstasy") is a recreational drug that has been shown to release serotonin (5-HT) and dopamine (DA) in animals. The effect of MDMA on 5-HT release can be blocked by 5-HT uptake inhibitors such as citalopram, suggesting that MDMA interacts with the 5-HT uptake site. It is unknown whether this mechanism is also responsible for the psychological effects of MDMA in humans. We investigated the effect of citalopram pretreatment (40 mg iv) on the psychological effects of MDMA (1.5 mg/kg po) in a double-blind placebo-controlled psychometric study in 16 healthy human volunteers. MDMA produced an emotional state with heightened mood, increased self-confidence and extroversion, moderate derealization, and an intensification of sensory perception. Most of these effects were markedly reduced by citalopram. This finding suggests that the psychological effects of MDMA are mediated via action at the 5-HT uptake site to increase 5-HT release through the carrier, as expected from animal studies.

Mood state and brain electric activity in ecstasy users

Resting EEG during open and closed eyes and subsequent mood ratings were obtained from 15 Ecstasy users and 14 Ecstasy-naive controls. Absolute spectral power on the scalp, and the three-dimensional, intracerebral distribution of neuroelectric activity using low resolution brain electromagnetic tomography (LORETA) were computed. LORETA revealed global increases of theta, alpha 1 and beta 2/3 power during eyes open in Ecstasy users, and spectral analyses revealed a right-posterior increase of alpha 2 power (confirmed by LORETA) and increased beta band activity during open eyes. Ecstasy users had higher levels of state depressiveness, emotional excitability and a trend-level increase in state anxiety. The observed differences may be related to regular exposure to Ecstasy or other illicit drugs, or may be pre-existing.

Psychological and cardiovascular effects and short-term sequelae of MDMA ("ecstasy") in MDMA-naïve healthy volunteers

3, 4-methylenedioxymethamphetamine (MDMA, "Ecstasy") is a recreational drug reported to produce a different psychological profile than that of classic hallucinogens and stimulants. It has, therefore, been tentatively classified into a novel pharmacological class termed entactogens. This double-blind placebo-controlled study examined the effects of a typical recreational dose of MDMA (1.7 mg/kg) in 13 MDMA-naïve healthy volunteers. MDMA produced an effective state of enhanced mood, well-being, and increased emotional sensitiveness, little anxiety, but no hallucinations or panic reactions. Mild depersonalization and derealization phenomena occurred together with moderate thought disorder, first signs of loss of body control, and alterations in the meaning of percepts. Subjects also displayed changes in the sense of space and time, heightened sensory awareness, and increased psychomotor drive. MDMA did not impair selective attention as measured by the Stroop test. MDMA increased blood pressure moderately, with the exception of one subject who showed a transient hypertensive reaction. This severe increase in blood pressure indicates that the hypertensive effects of MDMA, even at recreational doses, should not be underestimated, particularly in subjects with latent cardiovascular problems. Most frequent acute somatic complaints during the MDMA challenge were jaw clenching, lack of appetite, impaired gait, and restless legs. Adverse sequelae during the following 24 hours included lack of energy and appetite, feelings of restlessness, insomnia, jaw clenching, occasional difficulty concentrating, and brooding. The present findings are consistent with the hypothesis that MDMA produces a different psychological profile than classic hallucinogens or psychostimulants.

Functional hemispheric asymmetry and belief in ESP: towards a "neuropsychology of belief"

30 right-handed subjects were given a lateralized tachistoscopic lexical-decision task. Subjects' belief in extrasensory perception (ESP) was assessed with a single six-point scale; 16 subjects were designated as believers in ESP and 14 subjects as nonbelievers. Believers in ESP did not exhibit a hemispheric asymmetry for the task while nonbelievers exhibited the expected right visual-field/left-hemisphere dominance documented in the literature. Believers' lack of asymmetry was not caused by an impaired left-hemisphere performance but rather by a significantly enhanced lexical-decision accuracy in the left visual field/right hemisphere compared to nonbelievers. These results are compatible with previous studies indicating a correlation between belief in ESP and a bias for right-hemisphere processing. Moreover, the results are relevant for a discussion of an association between paranormal beliefs and schizotypy: highly schizotypal individuals are not only particularly prone to believe in ESP but are also known to show an attenuation of hemispheric asymmetries in lateralized verbal tasks due to an enhanced contribution of the right hemisphere. We suggest that the neurological basis of delusion-like beliefs may involve a release of right-hemisphere function from left-hemisphere control and sketch the focus of research for a future "neuropsychology of belief."