Consensus Paper: Cerebellum and Emotion

Over the past three decades, insights into the role of the cerebellum in emotional processing have substantially increased. Indeed, methodological refinements in cerebellar lesion studies and major technological advancements in the field of neuroscience are in particular responsible to an exponential growth of knowledge on the topic. It is timely to review the available data and to critically evaluate the current status of the role of the cerebellum in emotion and related domains. The main aim of this article is to present an overview of current facts and ongoing debates relating to clinical, neuroimaging, and neurophysiological findings on the role of the cerebellum in key aspects of emotion. Experts in the field of cerebellar research discuss the range of cerebellar contributions to emotion in nine topics. Topics include the role of the cerebellum in perception and recognition, forwarding and encoding of emotional information, and the experience and regulation of emotional states in relation to motor, cognitive, and social behaviors. In addition, perspectives including cerebellar involvement in emotional learning, pain, emotional aspects of speech, and neuropsychiatric aspects of the cerebellum in mood disorders are briefly discussed. Results of this consensus paper illustrate how theory and empirical research have converged to produce a composite picture of brain topography, physiology, and function that establishes the role of the cerebellum in many aspects of emotional processing.

Event-related potentials indicating impaired emotional attention in cerebellar stroke--a case study

The cerebellum has been implicated in affective and attentional processes, but little is known about corresponding neural signatures. We investigated early and late components of event-related potentials (ERPs) to emotionally arousing pictures, with and without competing attentional tasks, in a patient with an ischemic right posterior cerebellar infarction, at two months post infarct and two year follow-up. The early posterior negativity (EPN) response to highly arousing emotional cues in the competing visual attention condition revealed that the augmentation over occipital areas, as typically seen in normals, was absent post-infarct but was restored after two years. The late positive potentials (LPP) response to highly arousing emotional cues showed augmentation over frontal areas post-infarct, and over centro-parietal regions after two years. These ERP findings suggest a specific pattern of disruption of neural function associated with emotional-behavioral disturbances following cerebellar lesions, which can revert to normal with long term recovery.

[Schizophrenic disorders. The development of immunological concepts and therapy in psychiatry]

Immunological changes reported in patients with schizophrenia may play an aetiological role in these disorders. Further, immunomodulatory medications can influence the symptoms of psychiatric disorders. Antipsychotic agents such as clozapine may act therapeutically through the modulation of the immune system and also lead to side effects in that domain.Both the understanding and factual foundations of immunological concepts and immunological therapies of schizophrenic disorders have changed throughout the history of medicine. These are important considerations in psychiatry where diagnostic, nosological and therapeutic complexity is the norm. The article exemplarily presents publications of the psychiatrists such as Julius Wagner von Jauregg, Lewis Campbell Bruce and Friedrich Ostmann as well as neuropathologist Hermann Lehmann-Facius and haematologist William Dameshek.

A genome screen of 35 bipolar affective disorder pedigrees provides significant evidence for a susceptibility locus on chromosome 15q25-26

Bipolar affective disorder is a heritable, relatively common, severe mood disorder with lifetime prevalence up to 4%. We report the results of a genome-wide linkage analysis conducted on a cohort of 35 Australian bipolar disorder families which identified evidence of significant linkage on chromosome 15q25-26 and suggestive evidence of linkage on chromosomes 4q, 6q and 13q. Subsequent fine-mapping of the chromosome 15q markers, using allele frequencies calculated from our cohort, gave significant results with a maximum two-point LOD score of 3.38 and multipoint LOD score of 4.58 for marker D15S130. Haplotype analysis based on pedigree-specific, identical-by-descent allele sharing, supported the location of a bipolar susceptibility gene within the Z(max-1) linkage confidence interval of 17 cM, or 6.2 Mb, between markers D15S979 and D15S816. Non-parametric and affecteds-only linkage analysis further verified the linkage signal in this region. A maximum NPL score of 3.38 (P=0.0008) obtained at 107.16 cM (near D15S130), and a maximum two-point LOD score of 2.97 obtained at marker D15S1004 (affecteds only), support the original genome-wide findings on chromosome 15q. These results are consistent with four independent positive linkage studies of mood and psychotic disorders, and raise the possibility that a common gene for susceptibility to bipolar disorder, and other psychiatric disorders may lie in this chromosome 15q25-26 region.

FMR1 alleles in Tasmania: a screening study of the special educational needs population

The distribution of fragile X mental retardation-1 (FMR1) allele categories, classified by the number of CGG repeats, in the population of Tasmania was investigated in 1253 males with special educational needs (SEN). The frequencies of these FMR1 categories were compared with those seen in controls as represented by 578 consecutive male births. The initial screening was based on polymerase chain reaction analysis of dried blood spots. Inconclusive results were verified by Southern analysis of a venous blood sample. The frequencies of common FMR1 alleles in both samples, and of grey zone alleles in the controls, were similar to those in other Caucasian populations. Consistent with earlier reports, we found some (although insignificant) increase of grey zone alleles in SEN subjects compared with controls. The frequencies of predisposing flanking haplotypes among grey zone males FMR1 alleles were similar to those seen in other Caucasian SEN samples. Contrary to expectation, given the normal frequency of grey zone alleles, no premutation (PM) or full mutation (FM) allele was detected in either sample, with only 15 fragile X families diagnosed through routine clinical admissions registered in Tasmania up to 2002. An explanation of this discrepancy could be that the C19th founders of Tasmania carried few PM or FM alleles. The eight to ten generations since white settlement of Tasmania has been insufficient time for susceptible grey zone alleles to evolve into the larger expansions.

Attitudes toward psychiatry among students entering medical school

OBJECTIVE

To survey the attitudes of Australian medical students to determine their views about the relative attractiveness of psychiatry as a career compared with other specialties, and against findings from a North American study.

METHOD

We surveyed 655 first-year medical students attending six Australian Universities.

RESULTS

Responses indicated that Australian medical students view psychiatry as distinctly less 'attractive' than other career options, as reported in the North American sample. In comparison with other disciplines, psychiatry was regarded as more interesting and intellectually challenging, but also as lacking a scientific foundation, not being enjoyable and failing to draw on training experiences.

CONCLUSION

Our findings suggest that psychiatry has an image problem that is widespread, reflecting community perceptions and the specialist interests of medical students on recruitment. If psychiatry is to improve its 'attractiveness' as a career option, identified image problems need to be corrected and medical student selection processes re-considered.

Computer-aided vicarious exposure versus live graded exposure for spider phobia in children

The efficacy of computer-aided vicarious exposure (CAVE) for the treatment of spider phobia in children was evaluated in a single blind, randomised, controlled trial. Twenty-eight participants, aged 10-17 years, received three 45-min sessions of either Live graded exposure (LGE), CAVE or were assigned to a Waitlist. Phobic symptomatology was measured at pre- and post-treatment, and at one month follow-up on a range of behavioural and subjective assessments. The results showed the superiority of the LGE treatment over the CAVE and Waitlist conditions. Effect sizes support CAVE treatment as being superior to the Waitlist and resulting in reductions of phobic symptomatology.

Seasonal variation in hospital admission for bipolar disorder, depression and schizophrenia in Tasmania

OBJECTIVE

Seasonal variation has been reported for both affective disorders and schizophrenia. The current study examines seasonal variation in admissions in schizophrenia, depression and bipolar disorder in Tasmania, the southernmost state of Australia.

METHOD

All admissions with a diagnosis of schizophrenia, bipolar disorder and depression in Tasmania between 1983 and 1989 were examined for evidence of seasonal variation in admission patterns.

RESULTS

Using the modified Kolmogorov-Smirnov statistic defined by Freedman no significant seasonal variation was found in admissions with diagnoses of mania, depression or schizophrenia. There was a significant seasonal variation in admissions with schizoaffective disorder (winter peak).

CONCLUSION

There is no significant seasonal variation in admissions with schizophrenia, depression or bipolar disorder in Tasmania. This may be due to a combination of geographical location and the stringent test of seasonal variation used in the current study.

Process-outcome analysis in computer-aided treatment of obsessive-compulsive disorder

The study purpose was to examine dose-response relationships between behavior on a computer-delivered treatment program and outcome in obsessive-compulsive disorder (OCD), and to report the use of human-computer interactions (HCIs) as a process measure in psychotherapy research. Thirteen OCD patients completed three 45-minute sessions at weekly intervals on an interactive computer program which provided vicarious exposure and response prevention for OCD. The scenario modeled exposure to dirt for the treatment of a hand-washing ritual. HCIs were recorded and analyzed to provide a detailed description of the behavioral strategies used. The relationship between subject characteristics, process measures, and outcome was examined. Across the three computer treatment sessions, all subjects showed a marked increase in vicarious exposure behavior, that is, enacting a hand-dirtying behavior sequence on the interactive computer program. Some subjects enacted hand-washing, although this decreased across sessions. A higher amount of vicarious hand-dirtying behavior predicted symptom reduction on the Padua Inventory (PI). Higher National Adult Reading Test (NART) scores, an intelligence measure, predicted more enactments of hand-dirtying behavior, but the relationship between hand-dirtying and outcome remained significant after controlling for NART scores. We conclude that HCIs are a novel and objective process measure that may aid in clarifying specific treatment factors. The relationship between hand-dirtying and outcome suggests a likely increased benefit from higher treatment dosages.

Behavioral analysis of computer-administered vicarious exposure in agoraphobic subjects: the effect of personality on in-session treatment process

Pretreatment measures of personality and symptom levels in agoraphobic subjects (N = 18) were correlated with their behavior on an interactive computer simulation that provided vicarious exposure to a phobia of elevators. Behavior during treatment sessions was assessed via human-computer interactions (HCIs). Automated programs analyzed these interactions to provide detailed behavioral descriptions. All subjects engaged in vicarious exposure, but the extent of this varied eightfold. Vicarious exposure increased across treatment sessions, with a qualitative shift to a high-exposure routine of staying in the simulated elevator and repeatedly traveling the maximum number of floors. The amount of activity spent on traveling in the elevator increased from 43% to 62% across three treatment sessions. Correlations were observed between vicarious exposure behaviors and a number of subject characteristics including neuroticism and conscientiousness. We conclude that HCIs provide a detailed record of behavior during computer-administered treatment. Subjects demonstrate learning of exposure strategies across treatment sessions. Interindividual differences in behavior correlate with a number of pretreatment subject personality characteristics.

Comparison between register and structured interview diagnoses of schizophrenia: a case for longitudinal diagnostic profiles

OBJECTIVE

Mental health registers contain diagnoses from serial contacts with mental health facilities over many years. This study examines the relationship between longitudinal diagnostic profiles and structured interview diagnoses. The aim is to improve the definition of diagnoses drawn from clinical case registers.

METHOD

The Tasmanian Mental Health Case Register includes 1922 individuals, each with at least one diagnosis of schizophrenia between 1965 and 1990. A representative subsample of 29 individuals were assessed by the structured diagnostic interview for DSM-III-R (SCID). Diagnostic agreement between Register and SCID diagnoses was compared.

RESULTS

Twenty-four subjects (82.8%) received a lifetime diagnosis of schizophrenia on the SCID. For each subject, 'schizophrenia diagnostic dominance', the percentage of register entries with schizophrenia diagnoses over total entries, was calculated. Agreement between register and SCID correlated positively with schizophrenia diagnostic dominance and negatively with register mood diagnoses.

CONCLUSIONS

Longitudinal diagnostic profiles on databases may be superior to cross-sectional clinical diagnoses in predicting structured interview diagnoses, and may be useful in defining caseness in epidemiological studies using register diagnoses.

Predictability of rehospitalisation over 5 years for schizophrenia, bipolar disorder and depression

OBJECTIVE

The aim of this study was to examine the rate of rehospitalisation for schizophrenia, bipolar disorder and depression over a 5-year period in Tasmania, and to identify predictors of the number and duration of readmissions.

METHOD

The Tasmanian Mental Health Register was used to study the 5-year pattern of rehospitalisation for all patients admitted to a Tasmanian public psychiatric inpatient facility with a primary diagnosis of schizophrenia, bipolar disorder or depression, in 1983 or 1984.

RESULTS

Seventy-one percent of patients receiving a diagnosis of schizophrenia were readmitted in the 5-year period, compared to 59% for bipolar disorder and 48% for depression. For all three diagnoses, the number of prior admissions was a predictor of the number of readmissions and the total number of days spent in hospital in the follow-up period. Age and sex also had significant effects, which varied across diagnostic groups.

CONCLUSIONS

A substantial proportion of patients hospitalised for schizophrenia, bipolar disorder or schizophrenia were rehospitalised during the next 5 years. Patients with more previous admissions had more readmissions than those with fewer previous admissions.

A pilot study of computer-aided vicarious exposure for obsessive-compulsive disorder

OBJECTIVE

This study reports the use of an interactive computer program to instruct vicarious exposure and ritual prevention for obsessive-compulsive disorder (OCD).

METHOD

Thirteen OCD volunteers and 10 non-OCD volunteers completed three 45-minute sessions at weekly intervals. Subjects with OCD completed the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), the Padua Inventory (PI) and the Beck Depression Inventory (BDI) 1 week prior to and 1 week after the three computer treatment sessions. Non-OCD subjects only completed these measures at baseline, allowing confirmation that they had no significant level of OCD symptomatology.

RESULTS

In the OCD subjects, scores fell significantly on the PI and BDI, and Y-BOCS scores fell non-significantly. Engagement in vicarious exposure with ritual prevention improved from sessions 1-3. Compared to the non-OCD participants, OCD subjects did less vicarious exposure in session 1 but not sessions 2 and 3. Performance of vicarious exposure by OCD subjects in session 1 correlated with pre-post improvement in PI and BDI scores.

CONCLUSIONS

The vicarious exposure program may have a role to play as an adjunct in behaviour therapy.

Computer-delivered modeling of exposure for spider phobia: relevant versus irrelevant exposure

Spider phobic subjects (n = 45) completed 3 x 40 minute computer-delivered treatment sessions. Questionnaire ratings of phobic severity were completed pre- and posttreatment (n = 45) and 6-12 month follow-up (n = 38). The program used interactive animations to model self-exposure treatment methods. Subjects were randomized to one of three treatment groups (n = 15), each receiving a different version of the program. These treatment conditions were relevant exposure with feedback (REF), relevant exposure with no feedback (RENoF), or irrelevant exposure with feedback (IEF). Relevant exposure modeled exposure to spiders, irrelevant exposure to elevators. All groups showed significant phobic improvement following the treatment, as measured on a variety of instruments. Learning on the programs was demonstrated by a significantly increased performance (time taken to reach a target score) within each group across the three computer treatment sessions. Outcome was not significantly affected either relevance of exposure or the manipulation of the onscreen feedback. Subjects' report of exposure treatment undertaken at home correlated positively with phobic improvement.

Season of birth and schizophrenia in Tasmania

OBJECTIVE

The purpose of the present study was to determine whether there was a significant seasonal variation in the birth dates of patients with schizophrenia born in Tasmania.

METHOD

The season of birth in Tasmanian-born patients with schizophrenia (n = 1412), born between 1919-1970, was compared with general population data.

RESULTS

No significant variation in month or quarter of birth was detected for the subjects with schizophrenia. Neither was there any significant seasonal excess when data from different decades were analysed separately, nor for subsidiary analyses of gender or paranoid/non paranoid subtype.

CONCLUSION

These results are compared with those of six other published studies of Australasian-born subjects identified through registers in different States. While both positive and negative results are reported, no clear pattern emerges. The relevance of season of birth to the development of schizophrenia in Australia remains an open question.

Decline in diagnoses of schizophrenia in Tasmania during the period 1965-1990

Changes in the rates of diagnosis of schizophrenia in Tasmania, Australia during the period of 1965-1990 were examined using records from the State mental health case register. Analyses were restricted to subjects with diagnoses recorded between the ages of 20 and 29 years in order to reduce possible errors caused by age-standardized methods. There was a significant decrease in the rate of non-paranoid subtypes of schizophrenia in female subjects, accompanied by a commensurate rise in the rate of bipolar diagnoses in that group. Differential changes in male and female subjects support explanations of phenotypic shifts in presentation of psychosis as well as changes in diagnostic practice.

Computer aids to treatment in psychiatry

OBJECTIVE

A critical discussion is presented of computer-administered treatments in psychiatry, focusing on the results of outcome studies, the range of approaches under investigation, and advantages and disadvantages of this treatment approach.

METHOD

A selective review of controlled outcome studies, comparing computer and human therapist administered treatments in clinical populations was made.

RESULTS

The small number of studies reported suggest that computer administered forms are no less effective than human therapists for circumscribed, structured cognitive and behavioural interventions, and are acceptable to patients.

CONCLUSIONS

Putative computer-administered treatments will become commonplace. They will require thorough evaluation of benefits, risks and costs to determine their proper role in relations to the alternative treatments available.

Interference effects on verbal memory function, following oral lorazepam

Previous studies have consistently reported deficits in verbal memory following oral lorazepam administration. The possible role of susceptibility to interference effects as a contributory mechanism in benzodiazepine amnesia has not been examined as an independent variable. In addition, most studies of benzodiazepine amnesia have not controlled for the possible confounding effects of alcohol consumption, recently reported to affect the degree of amnesia produced by lorazepam. The present study assessed the verbal memory capabilities of 24 low social drinkers (MAST score < 3) receiving either oral lorazepam (2 mg) or placebo. Interference effects on verbal memory were assessed using the Auditory herbal Learning Test, with either the interference word list (trial B) or a counting backwards task. Lorazepam significantly reduced the recall scores for list B, compared to the first presentation of list A, suggesting lorazepam may increase susceptibility to proactive interference. There was no drug effect on retroactive interference. With regard to recall per se, lorazepam impaired verbal learning for initial acquisition trials (trials 2 and 3) but not subsequent trials, where learning was comparable to the placebo. Lorazepam did not produce significant impairment in immediate and delayed recall trials. This pattern of recall does not conform to the classic profile of benzodiazepine-induced amnesia; potential explanations for this are discussed.

Aetiology of spider phobia: classificatory differences between two origins instruments

The origins of fear of spiders was investigated in 33 spider phobic Ss entering a treatment study. All Ss completed Menzies and Clarke's (1993a) Origins Questionnaire (OQ) (Behaviour Research and Therapy, 31, 355-365) and Ost and Hugdahl's (1981) Phobic Origins Questionnaire (POQ) (Behaviour Research and Therapy, 19, 439-447). The results for the individual questionnaires were similar to those reported in previous studies. However a comparison of assignments of origin category for the two questionnaires showed widely discrepant results. The POQ returned 17 positive responses for classical conditioning, the OQ only 2. By contrast the OQ returned 10 origins as 'non-conditioning traumatic event', 9 of which returned positive responses for classical conditioning on the POQ. A further 15 Ss on the OQ were categorised as 'always been this way', the preponderance of these being classified as vicarious or informational in origin on the POQ. The POQ does not have a specific question or category for non-associative acquisition of phobias. The results of the origins assignments are detailed and their relation to the structure and questions of the questionnaires is outlined. Past studies using the POQ have produced results supporting acquisition of a substantial proportion of phobias by classical conditioning. The findings of this study suggest that such results mainly reflect inherent bias in that instrument.

Recovery after electroconvulsive therapy: comparison of propofol with methohexitone anaesthesia

We have studied prospectively 39 patients receiving a course of electroconvulsive therapy (ECT) for major depressive disorder; they were allocated randomly to receive either propofol or methohexitone for anaesthesia. Recovery after the third ECT treatment was assessed by finger tap and digit symbol substitution tests at 15, 30, 45, 60 and 90 min after induction. Seizure duration (median (interquartile range)) was shorter with propofol (24 (10) s) than methohexitone (29 (17) s) (P = 0.08). There was no significant difference in psychometric recovery for drug type, duration of the seizure or initial severity of depression. These results suggest that the more rapid recovery rates noted with propofol in other procedures are not evident after electrically induced seizures.

Comparison of propofol and methohexitone in anaesthesia for ECT: effect on seizure duration and outcome

The effect of the induction agents propofol and methohexitone on seizure duration and clinical outcome was assessed in a prospective, randomised, double blind study in 32 depressed patients receiving electroconvulsive therapy (ECT). Assessments comprised Hamilton rating scales pre-ECT, weekly during the course, and at one month follow-up. Patients showed a significant improvement in depression as measured by the Hamilton rating scale across the course of the ECT treatment. This improvement was not significantly different in the propofol and methohexitone groups. Nor was the amount of improvement related to either the total duration of seizure experienced by the patient during the ECT series or the use of tricyclic antidepressants by some patients.

A comparison of age-related deficits in memory and frontal lobe function following oral lorazepam administration

Differential responses on cognitive function of young (18-45 years, n = 17) and elderly (60-75 years, n = 9) subjects were compared before and after a challenge with lorazepam (2 mg oral) or placebo. Tests of memory and frontal lobe function were administered to determine the specificity of the amnesic deficit produced and the interaction of drug and the aging brain. Anterograde amnesia, as assessed by recall of a word list, was noted in both groups and was greater in the elderly. Whereas lorazepam produced only impaired recall in the young group, the elderly group manifested a further range of cognitive impairments, including decreased verbal fluency on the controlled oral word association test and reduced performance on the Wisconsin card-sorting test. These impairments in the elderly group could not be attributed to performance deficits pre-drug. Short-term memory, as evidenced by digit span and the copy trial of the Rey figure, was not impaired by lorazepam. It is concluded that whilst lorazepam produces a relatively `pure' amnesia in young to middle aged adults, in the elderly there is an admixture of deficits in some frontal lobe functions. This is presumed to reflect age-related changes in the brain and may be analogous to the spectrum of results noted in Korsakoff's psychosis as opposed to 'pure' diencephalic amnesia.

Amnesia following gastroscopy with midazolam: a comparison in two age groups

Forty patients, in two age groups, undergoing gastroscopy, received intravenous midazolam as the sole pre- medication. Mean ages were 35 (range 19-47) and 65.5 (range 53-75) and mean dosages 4.52 and 5.82 mg, respectively in the two groups. Neuropsychological testing pre- and post-medication comprised the Rey auditory verbal learning test (RAVLT), word association test, digit span and face memory test. The elderly group gave significantly more false-positive responses on recognition recall on the RAVLT and had significant impairment of reverse digit span. Following midazolam, in both age groups there was a significantly reduced rate of verbal learning and a marked deficit in delayed free recall coupled with substantial preservation of recognition recall. Word fluency and forward digit span were not affected. There was an increase in false-positive responses for face memory. These findings are consistent with a specific processing deficit affecting the acquisition of episodic long-term memory.

A comparison of the effect of lorazepam on memory in heavy and low social drinkers

The cognitive deficits, particularly memory impairment, observed in association with organic brain damage caused by chronic alcohol ingestion, are consistent with the profile of benzodiazepine-induced amnesia. This study examined the cognitive capabilities of a group of heavy social drinkers (n = 11) and a group of low social drinkers (n = 11) under the influence of a pharmacological challenge (lorazepam 2 mg) and a placebo treatment. Lorazepam impaired visual memory and verbal learning in both groups, but the effect of lorazepam was exacerbated in the heavy social drinkers for delayed recall of verbal material. Heavy social drinkers had lower verbal fluency scores and were less able to copy complex figures than low social drinkers whether or not the pharmacological challenge was present. Lorazepam induced deficits, in both groups, which confirmed to the classic profile of those observed in benzodiazepine-induced amnesia. The deficits, both in the absence and presence of lorazepam, shown by heavy social drinkers suggest that changes may have occurred in their brain functioning.

A comparison of the amnesic effects of lorazepam in alcoholics and non-alcoholics

The transient amnesia produced by lorazepam has been suggested to have much in common with the permanent amnesia associated with organic brain damage. The present study examined the amnesia associated with chronic alcoholism and acute lorazepam administration and hypothesised that because alcoholics have prior impairment, their response to lorazepam induced amnesia would differ from that of non-alcoholics. Memory functioning was tested in 20 chronic alcoholics and 20 non-alcoholic controls both before and after administration of either 2 mg lorazepam or a placebo. It was found that, although there were some discrepancies on some of the memory tests, both long term alcohol abuse and acute lorazepam administration impaired visual and verbal episodic memory but did not impair semantic or short-term memory (STM).

Proving the somaticist position: J. B. Friedreich on the nature and seat of mental disease

The emerging specialty of psychiatry in Germany in the first half of the nineteenth century showed a preoccupation with theoretical issues regarding whether mental disease was correctly attributed to somatic or psychic causes. J. B. Friedreich was a champion of the somaticist view, and the methods and evidence which he used to defend this position and which he presented as a series of proofs, are scrutinized in detail in this paper. This illustrates how the dichotomous debate between the somaticist and mentalist viewpoints was sustained by a speculative philosophical method based on a dualistic conception of body and soul and supported by subjective clinical observations ranging from succinct to banal or even absurd.

Comparison of the amnesic effects of midazolam and diazepam

Thirty patients undergoing gastroscopy received intravenous premedication with either midazolam or diazepam in a randomised double blind study. Mean dosages were similar for the midazolam (6.13 mg) and diazepam (6.4 mg) groups. Neuropsychological testing pre- and post-medication comprised the Wechsler Memory Scale, Complex Figure Test, Word Association Test, and a Tactile Memory Test. There was a significant impairment on post-medication tests requiring delayed recall of verbal, visual and tactile stimuli. Midazolam produced significantly greater anterograde amnesia than diazepam at similar mean dosages. With the exception of Digit Span and Associate Learning, cognitive tasks which do not require delayed recall were not affected. It is concluded that the amnesic deficit is discrete and not secondary to sedative effects.