Richard C Josiassen

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Patients with more recently diagnosed Huntington's disease (RHD) were compared on a neuropsychological test battery with patients who had had the disease one to eight years (moderate HD) and with asymptomatic offspring. Though the patients with HD showed deficits in motor and motor-independent abilities, the patients with RHD were less impaired on factors(More)
OBJECTIVE The authors evaluated the efficacy and safety of augmenting clozapine with risperidone in patients with treatment-resistant schizophrenia. METHOD In a randomized, double-blind, placebo-controlled 12-week trial, 40 patients unresponsive or partially responsive to clozapine monotherapy received a steady dose of clozapine combined with either(More)
Polydipsia among chronic psychiatric patients is poorly understood and underdiagnosed. It may have three stages: simple polydipsia, polydipsia with water intoxication, and physical complications. Epidemiological surveys have used staff reports and polyuria measures to identify polydipsic patients. Water intoxication has been screened by chart review,(More)
To replicate the findings of a sensory gating deficit in schizophrenia, and to determine if normals and schizophrenics are equally affected by cognitively mediated task-relevant factors, 10 healthy and 10 schizophrenic young adults were tested in two experimental conditions. In the first condition a pair of identical auditory clicks (conditioning stimulus(More)
In normal subjects after a single oral dose, haloperidol half-life has been reported to range 14.5-36.7 hours (or up to 1.5 days). After chronic administration, half-lives of up to 21 days have been reported. The objective of this study was to evaluate specific factors that might account for differences in haloperidol half-life in patients taking(More)
To determine if attentional factors influence the suppression of the auditory P50 in a conditioning-testing paradigm, known as the 'sensory gating' effect, we tested 10 healthy young adults in four experimental conditions. The first condition was the traditional passive conditioning-testing paradigm in which a pair of identical auditory clicks is(More)
To evaluate possible influences of differences in intelligence on evoked potential (EP) relations to psychopathology, EPs of subjects with high and low scores on Raven's Progressive Matrices were compared. EPs to left median nerve (LSEP), right median nerve (RSEP), visual (VEP), and auditory (AEP) stimul were recorded from 15 leads. EPs of age- and(More)
Symbolic measures of complexity provide a quantitative characterization of the sequential structure of symbol sequences. Promising results from the application of these methods to the analysis of electroencephalographic (EEG) and event-related brain potential (ERP) activity have been reported. Symbolic measures used thus far have two limitations, however.(More)
Auditory and visual evoked potentials elicited by acoustic click (AEP) and checkerboard pattern flash (VEP) were recorded from 15 locations in 21 patients with Huntington's disease (HD) and 21 controls matched for age and sex. Peak latencies were approximately the same for both groups, except that AEP peak N100 appeared earlier in HDs. The main deviation in(More)