Modulation of brain response to emotional images by alcohol cues in alcohol-dependent patients

Alcohol is often used to modulate mood states. Alcohol drinkers report that they use alcohol both to enhance positive affect and to reduce dysphoria, and alcohol-dependent patients specifically state reduction of negative affect as a primary reason for drinking. The current study proposes that alcohol cues may reduce negative affect in alcoholics. We used functional magnetic resonance imaging to examine brain activation in response to combination images that juxtaposed negative or positive International Affective Picture System (IAPS) images with an alcohol or non-alcohol-containing beverage. We found that in the absence of the alcohol cue, alcoholics showed more activation to negative than to positive images and greater activation than controls to negative images. When the IAPS images were presented with the alcohol cue, there was a decreased difference in activation between the positive and negative images among the alcoholics, and a decreased difference in response to the negative images between controls and alcoholics. Additionally, in the neutral-beverage conditions, anxiety ratings significantly predicted activation in the right parahippocampal gyrus but did not predict activation when the alcohol cues were presented. In conclusion, the alcohol cues may have modulated cortical networks involved in the processing of emotional stimuli by eliciting a conditioned response in the alcoholics, but not in the controls, which may have decreased responsiveness to the negative images.

Incentive-elicited striatal activation in adolescent children of alcoholics

AIMS

Deficient recruitment of motivational circuitry by non-drug rewards has been postulated as a pre-morbid risk factor for substance dependence (SD). We tested whether parental alcoholism, which confers risk of SD, is correlated with altered recruitment of ventral striatum (VS) by non-drug rewards in adolescence.

DESIGN

During functional magnetic resonance imaging, adolescent children of alcoholics (COA; age 12-16 years) with no psychiatric disorders (including substance abuse) and similarly aged children with no risk factors responded to targets to win or avoid losing $0, $0.20, $1, $5 or a variable amount (ranging from $0.20 to $5).

RESULTS

In general, brain activation by either reward anticipation or outcome notification did not differ between COA and age/gender-matched controls. Cue-elicited reward anticipation activated portions of VS in both COA and controls. In nucleus accumbens (NAcc), signal change increased with anticipated reward magnitude (with intermediate recruitment by variable incentives) but not with loss magnitudes. Reward deliveries activated the NAcc and mesofrontal cortex in both COA and controls. Losses activated anterior insula bilaterally in both groups, with more extensive right anterior insula activation by losses in controls. NAcc signal change during anticipation of maximum rewards (relative to non-reward) correlated positively with both Brief Sensation-Seeking Scale scores and with self-reported excitement in response to maximum reward cues (relative to cues for non-reward).

CONCLUSIONS

Among adolescents with no psychiatric disorders, incentive-elicited VS activation may relate more to individual differences in sensation-seeking personality than to presence of parental alcoholism alone. Future research could focus on adolescents with behavior disorders or additional risk factors.

Striatal sensitivity to reward deliveries and omissions in substance dependent patients

Some motivational theories of substance dependence (SD) posit either pathologically increased or decreased ventral striatum (VS) recruitment by cues for nondrug rewards. The incentive-sensitization hypothesis, alternatively, attributes SD to enhanced incentive salience of drug-predictive cues specifically, with no requirement for altered nondrug incentive processing. We assessed whether individuals undergoing inpatient therapy for SD are characterized by altered recruitment of mesolimbic incentive neurocircuitry by cues and deliveries of nondrug rewards. During functional magnetic resonance imaging, substance-dependent patients (SDP) and controls performed a modified monetary incentive delay task featuring: a) anticipatory cues that signaled opportunities to respond to a target to either win money or avoid losing money, b) notifications of wins and losses, and c) unexpected replacement of reward trial outcomes with a demand to repeat the trial. Both anticipatory reward cues and loss cues elicited similar mood responses and VS activation between SDP and controls. However, in SDP (but not controls), reward notifications also activated VS and mesial frontal cortex, and loss notifications activated anterior insula. Finally, substitution of expected outcomes in reward trials with notifications to repeat the trial deactivated the VS in SDP but not in controls. These data do not suggest that SD is characterized by altered recruitment of VS circuitry by cues for nondrug incentives. Rather, SDP may instead have increased limbic system sensitivity to reward and loss delivery, consistent with the role of impulsivity in SD.

Reduced posterior mesofrontal cortex activation by risky rewards in substance-dependent patients

Substance-dependent individuals show disadvantageous decision-making, as well as alterated frontocortical recruitment when performing experimental tasks. We investigated whether substance-dependent patients (SDP) would show blunted recruitment of posterior mesofrontal cortex (PMC) by a conflict between concurrently increasing reward and risk of penalty in a monetary game of "chicken." SDP and controls performed: motor control (no reward) trials, guaranteed reward trials in which reward was not at risk, and risky trials where subjects were required to terminate their reward accrual before a secret varying time limit or else "bust" and forfeit that trial's winnings (low penalty) or the current trial's winnings plus an equal amount of previous winnings (high penalty). Reward accrual duration at risk of "busting" correlated negatively with trait neuroticism. The contrast between winning guaranteed reward versus non-reward activated the caudate head bilaterally in SDP but not controls. Accumulation of money at risk of low- or high-penalty (contrasted with accumulating guaranteed money) activated the PMC in both groups, but with a greater magnitude and more anterior extent in controls. Pre-decision signal increase in a PMC volume of interest negatively correlated with risk-taking in low-penalty trials, and was blunted in SDP relative to controls under both penalty conditions after controlling for individual differences in actual risk-taking and the higher neuroticism of SDP. These data suggest that SDP are characterized by a combination of: (a) striatal hypersensitivity to reward, and (b) under-recruitment of the specialized conflict-monitoring circuitry of the PMC when reward entails potential penalties.

Parental alcohol use and brain volumes in early- and late-onset alcoholics

BACKGROUND

Studies have shown that alcoholics have smaller brain volumes than non-alcoholic cohorts, but an effect of family history (FH) of heavy drinking on brain volume has not been demonstrated. We examined the relationship between an FH of heavy drinking and both brain shrinkage as measured by the ratio of brain volumes to intracranial volume (ICV) as well as maximal brain growth as measured by ICV in early-onset and late-onset alcoholics.

METHODS

With T1-weighted resonance imaging, we measured ICV, brain volume, and white and gray matter volume in adult treatment-seeking late-onset and early-onset alcoholics with either a positive or a negative FH of heavy alcohol use, and in healthy control subjects. We also calculated brain shrinkage using a ratio of soft tissue volumes to ICV.

RESULTS

The FH positive alcoholic patients had significantly smaller ICVs than FH negative patients, suggesting smaller premorbid brain growth. Brain shrinkage did not correlate with FH. Late-onset alcoholics showed a greater difference in ICV between FH positive and FH negative patients than early-onset alcoholics. Late-onset FH positive patients also had significantly lower IQ scores than late-onset FH negative patients, and IQ scores were correlated with ICV.

CONCLUSIONS

These data provide evidence that parental alcohol use might increase risk for alcoholism in offspring in part by a genetic and/or environmental effect that might be related to reduced brain growth.

Blunted rostral anterior cingulate response during a simplified decoding task of negative emotional facial expressions in alcoholic patients

BACKGROUND

Alcoholism is characterized by deficits in emotional functioning as well as by deficits in cognitive functioning. However, most brain imaging research on alcoholism has focused on cognition rather than emotion.

METHOD

We used an event-related functional magnetic imaging approach to examine alcoholics' brain blood oxygenation level dependent (BOLD) response to evaluation of emotional stimuli and to compare their response to that of nonalcoholic controls. The task used was a simplified variant of a facial emotion-decoding task in which subjects determined the intensity level of a target emotion displayed as a facial expression. Facial expressions of happy, sad, anger, disgust, and fear were used as stimuli.

RESULTS

Alcoholics and controls did not differ in accurately identifying the intensity level on the simple emotional decoding task but there were significant differences in their BOLD response during evaluation of facial emotion. In general, alcoholics showed less brain activation than nonalcoholic controls. The greatest differences in activation were during decoding of facial expressions of fear and disgust during which alcoholics had significantly less activation than controls in the affective division of the anterior cingulate cortex (ACC). Alcoholics also had significantly less activation than controls in the affective division of the ACC, while viewing sad faces. Only to facial expressions of anger did the alcoholics show significant activation in the affective ACC and in this case, their BOLD response did not significantly differ from that of the controls.

CONCLUSION

Alcoholics show a deficit in the function of the affective division of the ACC during evaluation of negative facial emotions that can serve as cues for flight or avoidance. This deficit may underlie some of the behavioral dysfunction in alcoholism.

Relationships among aging, IQ, and intracranial volume in alcoholics and control subjects

The current article examined the relationships among aging, intelligence, intracranial volume, and brain shrinkage in alcoholics and nonalcoholic controls. Magnetic resonance imaging was used to measure intracranial and cerebral volumes in 146 subjects with alcohol use disorders and 42 comparison subjects who were not alcoholic. The authors' findings show that performance on Block Design decreases as alcoholics age, and this decrease is predicted by brain shrinkage. This is consistent with a process of cumulative brain damage related to alcohol use. However, the authors' data also show that vocabulary does not decrease with age and is correlated with premorbid brain size as measured by intracranial volume, suggesting that lower verbal ability precedes heavy alcohol use and may be a risk factor for alcoholism.

Developmental differences in posterior mesofrontal cortex recruitment by risky rewards

Might increased risk taking in adolescence result in part from underdeveloped conflict-monitoring circuitry in the posterior mesofrontal cortex (PMC)? Adults and adolescents underwent functional magnetic resonance imaging during a monetary game of "chicken." As subjects watched ostensible winnings increase over time, they decided when to press a button to bank their winnings, knowing that if they did not stop pursuing money reward before a secret varying time limit, they would "bust" and either lose the money accrued on the current trial (low-penalty trials) or forfeit trial winnings plus a portion of previous winnings (high-penalty trials). Reward accrual at risk of low penalty (contrasted with guaranteed reward) activated the PMC in adults but not in adolescents. Across all subjects, this activation (1) correlated positively with age but negatively with risk exposure and (2) was greater when subjects busted on the previous low-penalty trial. Reward accrual at risk of high penalty was terminated sooner and recruited the PMC in both adults and adolescents when contrasted with guaranteed reward. Predecision PMC activation in the high-penalty trials was significantly reduced in trials when subjects busted. These data suggest that (1) under threat of an explicit severe penalty, recruitment of the PMC is similar in adolescents and adults and correlates with error avoidance, and (2) when potential penalties for a rewarding behavior are mild enough to encourage some risk taking, predecision PMC activation by a reward/risk conflict is sensitive to previous error outcomes, predictive of risk-aversive behavior in that trial, and underactive in adolescents.

Anticipating instrumentally obtained and passively-received rewards: a factorial fMRI investigation

During functional magnetic resonance imaging (fMRI), subjects saw cues signaling probabilities of 1.0, 0.5, and 0 of winning $1 for hitting a subsequent target, and cues signaling similar probabilities of reward delivery requiring no instrumental response. Non-instrumental reward anticipation did not elicit activation. Instrumental reward anticipation activated multiple nodes of the basal ganglia-thalamocortical motor circuit. Ventromesial striatum was activated by joint requirement for an instrumental response together with uncertain (but not certain) reward.

Single subject image analysis using the complex general linear model--an application to functional magnetic resonance imaging with multiple inputs

A linear time invariant model is applied to functional fMRI blood flow data. Based on traditional time series analysis, this model assumes that the fMRI stochastic output sequence can be determined by a constant plus a linear filter (hemodynamic response function) of several fixed deterministic inputs and an error term assumed stationary with zero mean. The input function consists of multiple exponential distributed (time delay between images) visual stimuli consisting of negative and erotic images. No a priori assumptions are made about the hemodynamic response function that, in essence, is calculated at each spatial position from the data. The sampling rate for the experiment is 400 ms in order to allow for filtering out higher frequencies associated with the cardiac rate. Since the statistical analysis is carried out in the Fourier domain, temporal correlation problems associated with inference in the time domain are avoided. This formal model easily lends itself to further development based on previously developed statistical techniques.

Childhood-onset schizophrenia: smooth pursuit eye-tracking dysfunction in family members

BACKGROUND

Childhood-onset schizophrenia (COS), a severe form of the disorder, is of interest for etiologic studies. Smooth pursuit eye-tracking dysfunction (ETD) is a biological marker for schizophrenia.

AIMS

To compare familial eye-tracking abnormalities for COS and adult-onset schizophrenia (AOS).

METHOD

Eye-tracking performance for 70 COS parents, 64 AOS parents and 20 COS siblings was compared to their respective age-matched control groups.

RESULTS

COS and AOS parents had higher rate of dichotomously rated eye-tracking dysfunction than their respective controls (16% vs. 1% and 22% vs. 4%, respectively). COS parents and siblings also differed from controls on several continuous measures. However, scores for COS, AOS and control groups overlapped extensively.

CONCLUSIONS

Genetic factors underlying eye-tracking dysfunction appear more salient for COS. However, eye-tracking measures have to be used with caution for endophenotypic definition due to low predictive power.

DECLARATION OF INTEREST

The study was done at the National Institutes of Health.

Impulsivity in abstinent alcohol-dependent patients: relation to control subjects and type 1-/type 2-like traits

Extensive literature has linked behavior control problems in childhood to risk for alcoholism, but impulsivity in alcohol-dependent adults has not been well characterized. Using a variety of laboratory measures of impulsivity, we assessed whether detoxified alcohol-dependent patients [(ADP); n = 130] were more impulsive than control subjects [(CS); n = 41]. In comparison with CS, ADP demonstrated (1) increased rates of commission errors, but not omission errors, in a continuous performance test, (2) a more severe devaluation of delayed reward, (3) increased rates of risky responses in a new risk-taking paradigm, and (4) higher psychometric scores of impulsivity and aggression. Across all subjects, aggressiveness correlated significantly with severity of delay discounting. A post hoc analysis of data obtained for male ADP indicated that, in comparison with patients with late onset of problem drinking and no problem-drinking parent, those ADP with earlier age of problem drinking and who reported a problem-drinking father (type 2-like alcohol dependence) demonstrated faster response latencies and more responses to non-target stimuli (commission errors) in the continuous performance test, as well as higher psychometric aggression. In contrast, these subtypes of male ADP did not differ in delay discounting and risk taking. These findings collectively indicate that, in comparison with CS, ADP are more impulsive in several dimensions, with elevated impulsivity in a working memory task as well as aggressivity characteristic of alcohol-dependent men with type 2-like features.

Incentive-elicited brain activation in adolescents: similarities and differences from young adults

Brain motivational circuitry in human adolescence is poorly characterized. One theory holds that risky behavior in adolescence results in part from a relatively overactive ventral striatal (VS) motivational circuit that readily energizes approach toward salient appetitive cues. However, other evidence fosters a theory that this circuit is developmentally underactive, in which adolescents approach more robust incentives (such as risk taking or drug experimentation) to recruit this circuitry. To help resolve this, we compared brain activation in 12 adolescents (12-17 years of age) and 12 young adults (22-28 years of age) while they anticipated the opportunity to respond to obtain monetary gains as well as to avoid monetary losses. In both age groups, anticipation of potential gain activated portions of the VS, right insula, dorsal thalamus, and dorsal midbrain, where the magnitude of VS activation was sensitive to gain amount. Notification of gain outcomes (in contrast with missed gains) activated the mesial frontal cortex (mFC). Across all subjects, signal increase in the right nucleus accumbens during anticipation of responding for large gains independently correlated with both age and self-rated excitement about the high gain cue. In direct comparison, adolescents evidenced less recruitment of the right VS and right-extended amygdala while anticipating responding for gains (in contrast with anticipation of nongains) compared with young adults. However, brain activation after gain outcomes did not appreciably differ between age groups. These results suggest that adolescents selectively show reduced recruitment of motivational but not consummatory components of reward-directed behavior.

Cross-sectional volumetric analysis of brain atrophy in alcohol dependence: effects of drinking history and comorbid substance use disorder

OBJECTIVE

The authors assessed whether individual differences in drinking history as well as lifetime incidence of comorbid cocaine or marijuana use disorder underlie differential patterns of brain atrophy in subjects with alcohol dependence.

METHOD

Segmented magnetic resonance images were used to compare whole brain cerebral gray matter and white matter in 134 male subjects age 30-50 with alcohol dependence, either alone or with comorbid cocaine or marijuana use disorder.

RESULTS

Across all subjects, drinking history variables correlated negatively with both gray matter and white matter after age was controlled. Alcohol-dependent subjects with no comorbid substance use disorder (N=51) showed a steeper negative correlation between age and the gray matter/white matter ratio than did alcohol-dependent subjects with a comorbid lifetime cocaine use disorder diagnosis (N=50). Alcohol-dependent subjects with comorbid cocaine use disorder tended to have a steeper negative correlation between age and white matter (adjusted for intracranial volume) than did alcohol-dependent subjects with no comorbid substance use disorder. After age and the greater estimated cumulative alcohol consumption of alcohol-dependent subjects with comorbid cocaine use disorder were controlled in a multiple regression analysis, however, comorbid cocaine use disorder did not account for any independent variance in any volumetric measure.

CONCLUSIONS

Brain atrophy among subjects with alcohol dependence reflects individual differences in exposure to alcohol, and the data provide mixed evidence that comorbid cocaine use disorder may exacerbate white matter atrophy in alcoholism.

CSF monoamine metabolites and MRI brain volumes in alcohol dependence

Correlations between cerebrospinal fluid (CSF) concentrations of monoamine metabolites (MAM) and brain structure have been described in schizophrenia, but not in alcoholism. To investigate the relationship between monoaminergic transmission and brain structure in alcoholism, the metabolites of dopamine (homovanillic acid, HVA), norepinephrenine (3-methoxy-4-hydroxyphenylethyleneglycol, MHPG) and serotonin (5-hydroxyindoleacetic acid, 5-HIAA) were measured in lumbar CSF in 54 alcohol-dependent patients and 20 healthy subjects. The volumes of the cerebrum, total grey and white matter, total and ventricular CSF, left and right hippocampus, and corpus callosum area were measured with MRI. MHPG and age were positively correlated in alcoholic women. The MAM concentrations were not significantly correlated with the MRI volumes in the subject categories. There were no differences in MAM across subjects defined by diagnosis and gender, age of onset of alcoholism or comorbidity of psychiatric disorders. Total CSF, cerebrum, and white and grey matter tissue volumes differed between patients and healthy subjects. The greatest difference was the white matter reduction in alcoholic women. In alcoholic women and men, monoaminergic neurotransmission measured by the CSF MAM HVA, MHPG, and 5-HIAA is not significantly correlated with the size of different brain structures.

Male and female sensitivity to alcohol-induced brain damage

Women are more vulnerable than men to many of the medical consequences of alcohol use. Although research has shown that male alcoholics generally have smaller brain volumes than nonalcoholic males, the few studies that have compared brain structure in alcoholic men and women have had mixed results. To adequately compare brain damage between alcoholic women and men, it is necessary to control for age and to have separate control groups of nonalcoholic men and women. Although the majority of studies suggest that women are more vulnerable to alcohol-induced brain damage than men, the evidence remains inconclusive.

Altered performance on an ocular fixation task in attention-deficit/hyperactivity disorder

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is a common psychiatric disorder without validated objective markers. Eye movement studies may be useful in providing objective criteria for characterizing the disorder.

METHODS

We compared 53 children (29 girls) with ADHD to 44 healthy control children (18 girls) on a 21-sec fixation task. Large saccades (> 4 degrees ) away from the fixation point were analyzed.

RESULTS

Children with ADHD made more large saccades that interrupted fixation than did control children (p =.001). Mean scores of the ADHD group did not change significantly with subsequent retesting on placebo (p =.11); however, there was poor intrasubject correlation (r =.16).

CONCLUSIONS

Both boys and girls with ADHD made significantly more intrusive saccades during fixation than did control subjects, possibly reflecting intrinsic neurologic dysfunction; however, a probable "floor effect" obviates conclusions about the reliability of this measure.

Smooth pursuit eye-tracking impairment in childhood-onset psychotic disorders

OBJECTIVE

Although childhood-onset schizophrenia is relatively rare, a sizable group of children with severe emotional disturbances have transient psychotic symptoms that fall outside of current syndrome boundaries. The relationship of this group of children to those with childhood-onset schizophrenia and other childhood psychiatric disorders is unclear. In this study, the authors compared smooth pursuit eye tracking, a biological trait marker associated with schizophrenia, of children and adolescents with psychotic disorder not otherwise specified to that of children with childhood-onset schizophrenia and healthy comparison subjects.

METHOD

By means of infrared oculography, smooth pursuit eye movements during a 17 degrees /second visual pursuit task were quantitatively and qualitatively compared in 55 young adolescents (29 with childhood-onset schizophrenia and 26 with psychotic disorder not otherwise specified) and their respective independent healthy comparison groups (a total of 38 healthy subjects).

RESULTS

Subjects with childhood-onset schizophrenia had qualitatively poorer eye tracking, higher root mean square error, lower gain, and a greater frequency of catch-up saccades than healthy children. Subjects with psychotic disorder not otherwise specified also had qualitatively poorer eye tracking, higher root mean square error, and lower gain than healthy children, but saccade frequency did not differ significantly.

CONCLUSIONS

Children with childhood-onset schizophrenia exhibit a pattern of eye-tracking dysfunction similar to that reported for adult patients. Similar abnormalities were seen in the subjects with psychotic disorder not otherwise specified except that they did not exhibit a greater frequency of catch-up saccades. Prospective longitudinal neurobiological and clinical follow-up studies of both groups are currently underway to further validate the distinction between these two disorders. Also, family studies are planned to establish whether eye-tracking dysfunction represents a trait- or state-related phenomenon in subjects with psychotic disorder not otherwise specified.

Neuroimaging in alcoholism: ethanol and brain damage

This article represents the proceedings of a symposium at the 2000 ISBRA Meeting in Yokohama, Japan. The co-chairs were Karl Mann and Ingrid Agartz. The presentations were (1) Neuropathological changes in alcohol-related brain damage, by Clive Harper; (2) Regional brain volumes including the hippocampus and monoamine metabolites in alcohol dependence, by Ingrid Agartz, Susan Shoaf, Robert R, Rawlings, Reza Momenan, and Daniel W Hommer; (3) Diffusion tensor abnormalities in imaging of white matter alcoholism, by Adolf Pfefferbaum and Edith V. Sullivan; (4) Use of functional MRI to evaluate brain activity during alcohol cue exposure in alcoholics: Relationship to craving, by Raymond F. Anton, David J. Drobes, and Mark S. George; and (5) mu-Opiate receptor availability in alcoholism: First results from a positron emission tomography study, by Karl Mann, Roland Bares, Hans-Juergen Machulla, Goetz Mundle, Matthias Reimold, and Andreas Heinz.

Premorbid speech and language impairments in childhood-onset schizophrenia: association with risk factors

OBJECTIVE

As both premorbid neurodevelopmental impairments and familial risk factors for schizophrenia are prominent in childhood-onset cases (with onset of psychosis by age 12), their relationship was examined.

METHOD

Premorbid language, motor, and social impairments were assessed in a cohort of 49 patients with childhood-onset schizophrenia. Familial loading for schizophrenia spectrum disorders, familial eye-tracking dysfunction, and obstetrical complications were assessed without knowledge of premorbid abnormalities and were compared in the patients with and without developmental impairments.

RESULTS

Over one-half of the patients in this group had developmental dysfunction in each domain assessed. The patients with premorbid speech and language impairments had higher familial loading scores for schizophrenia spectrum disorders and more obstetrical complications, and their relatives had worse smooth-pursuit eye movements. The boys had more premorbid motor abnormalities, but early language and social impairments did not differ significantly between genders. There were no other significant relationships between premorbid social or motor abnormalities and the risk factors assessed here.

CONCLUSIONS

Premorbid developmental impairments are common in childhood-onset schizophrenia. The rates of three risk factors for schizophrenia (familial loading for schizophrenia spectrum disorders, familial eye-tracking dysfunction, and obstetrical complications) were increased for the probands with premorbid speech and language impairments, suggesting that the pathophysiology of schizophrenia involves the abnormal development of language-related brain regions.

Executive function oculomotor tasks in girls with ADHD

OBJECTIVE

To assess executive function in girls with attention-deficit/hyperactivity disorder (ADHD) using oculomotor tasks as possible trait markers for neurobiological studies.

METHOD

Thirty-two girls aged 6 to 13 years with DSM-IV ADHD and 20 age-matched, normal control girls were tested on a variety of oculomotor tasks requiring attention, working memory, and response inhibition, which included smooth pursuit, delayed response, and go-no go tasks.

RESULTS

Girls with ADHD performed the delayed response task correctly on 32% of trials as measured by number of memory-guided saccades, in contrast to 62% of trials for control subjects (p = .0009). Patients made twice as many commission errors to no go stimuli (p = .0001) and 3 times as many intrusion errors (saccades in the absence of go or no go stimuli; p = .004) during the go-no go task compared with controls. Smooth pursuit performance was statistically equivalent across subject groups. Repeated testing in a subgroup of 15 patients revealed substantial practice effects on go-no go performance.

CONCLUSIONS

The data confirm that girls with ADHD exhibit impairments in executive function, as has been reported in boys, implying a similar pathophysiology of ADHD in both sexes. However, practice effects may limit the utility of the oculomotor go-no go task for some neurobiological studies.

Hippocampal volume in patients with alcohol dependence

BACKGROUND

Smaller hippocampal volumes have been reported in the brains of alcoholic patients than in those of healthy subjects, although it is unclear if the hippocampus is disproportionally smaller than the brain as a whole. There is evidence that alcoholic women are more susceptible than alcoholic men to liver and cardiac damage from alcohol. It is not known whether the hippocampi of the female brain are more vulnerable to alcohol.

METHODS

We compared the hippocampal volumes in 52 hospitalized alcoholic men and women with those of 36 healthy nonalcoholic men and women. All subjects were between 27 and 53 years of age. The hippocampal volumes were measured from sagittal T-weighted high-resolution magnetic resonance images.

RESULTS

The alcoholic women had less lifetime drinking and a later age at onset of heavy drinking than alcoholic men. Both alcoholic men and women had significantly smaller right hippocampi and larger cerebrospinal fluid volumes than healthy subjects of the same sex. Only among women were the left hippocampus and the nonhippocampal brain volume also significantly smaller. The proportion of hippocampal volume relative to the rest of the brain volume was the same in alcoholic patients and healthy subjects, in both men and women. The right hippocampus was larger than the left among all subjects. Women demonstrated larger hippocampal volumes relative to total brain volume than men. Psychiatric comorbidity, including posttraumatic stress disorder, did not affect hippocampal volume.

CONCLUSIONS

In chronic alcoholism, the reduction of hippocampal volume is proportional to the reduction of the brain volume. Alcohol consumption should be accounted for in studies of hippocampal damage.