[Clinical characteristics of patients with slow progressive schizophrenia combined with alcoholism]

Fifty-eight patients with slow progressive schizophrenia combined with alcoholism have been examined. Different variants of affective pathology described determined an alcohol addiction in patients with slow progressive schizophrenia. According to the structure of affective disorders and related types of excessive drinking, 3 groups of patients were identified. Group 1 was characterized by negative affection with detachment, continuous (progressive) type of alcoholism course and constant type of alcohol use; group 2 was characterized by positive affection with undulatory course of alcoholism and alcohol use, pseudo-drinking-bout type. Group 3 was distinguished by positive affection with distinct timing of disorder appearance, periodic course of alcoholism and spontaneous form of alcohol drinking. The most unfavorable prognosis was for group 1 and favorable one--for group 3.

Executive function deficits associated with symptoms of schizotypy and obsessive-compulsive disorder

Research suggests that executive dysfunction is seen both in disorders of the schizophrenia constellation and in obsessive-compulsive disorder (OCD), but that the patterns of executive deficits may differ. While disorders of the schizophrenia spectrum reflect impairment of functions such as integration of cognitive activities, a tendency to perseverate, and a failure to notice details (e.g. impairment associated with the dorsolateral prefrontal cortex), OCD may involve problems of impulse control and regulation of behavior, and an inability to maintain cognitive set (e.g. impairment associated with the orbitofrontal cortex). The present study examined differences between high-scorers on a measure of schizotypy, high-scorers on a measure of OCD, high-scorers on both schizotypy and OCD and a control group in performance on executive function tests. As expected, the OCD group demonstrated relative deficits on measures thought to reflect orbitofrontal functioning. However, contrary to expectations, the schizotypal group did not demonstrate deficits on neuropsychological tests thought to reflect dorsolateral prefrontal cortex functioning, and the combined group showed no executive impairment.

Schizotypal personality disorder inside and outside the schizophrenic spectrum

The concept of schizotypal personality disorder has been heavily discussed since its introduction into the official classification of mental disorders in DSM-III. The aim of this study was to investigate the difference between schizotypal personality disorder within and outside the genetic spectrum of schizophrenia. Schizotypals with and without schizophrenic cotwins and first-degree relatives were compared, with individuals with other mental disorders and no mental disorders as controls. It appeared that only inadequate rapport and odd communication were more pronounced among schizotypals within, compared to schizotypals outside the schizophrenic spectrum. Schizotypals outside the schizophrenic spectrum, however, scored higher than schizotypals inside the schizophrenic spectrum on ideas of reference, suspiciousness, paranoia, social anxiety, self-damaging acts, chronic anger, free-floating anxiety and sensitivity to rejection. Interestingly, the four last features are seldom observed among schizotypals inside the schizophrenic spectrum. Monozygotic non-schizophrenic cotwins of schizophrenics score high on inadequate rapport, odd communication, social isolation and delusions/hallucinations. Monozygotic non-schizophrenic cotwins of schizotypals outside the schizophrenic genetic spectrum score high on illusions, depersonalization, derealization and magical thinking. Negative schizotypal features appear to be inside the schizophrenic spectrum, while positive borderline-like features are outside having another genetic endowment.

The structure of schizotypy: relationships between neurocognitive and personality disorder features in relatives of schizophrenic patients in the UCLA Family Study

Schizotypal personality features and certain neurocognitive deficits have been shown to aggregate in the relatives of schizophrenic patients, supporting the view that both are likely to reflect genetic contributions to liability to schizophrenia. Within the relatives of schizophrenic patients, however, the interrelationships between these potential indicators of liability to schizophrenia are not well known. Using data from the UCLA Family Study, we examine the interrelationships between personality disorder symptoms and neurocognitive functioning in nonpsychotic first-degree relatives of schizophrenic patients. Factor analyses indicate that several dimensions of schizotypy can be identified. A neurocognitive dysfunction dimension includes loadings from measures of sequential visual conceptual tracking, rapid perceptual encoding and search, and focused, sustained attention as well as the rating of odd and eccentric behavior from schizotypal personality disorder. Other aspects of schizotypal personality disorder form separate positive schizotypy and negative schizotypy dimensions. These analyses support the view that schizotypy is multidimensional in relatives of schizophrenic patients and indicate that neurocognitive deficits in perception and attention are associated with particular schizotypal personality features.

Elucidating continuities and discontinuities between schizotypy and schizophrenia in the nervous system

Genetic epidemiological studies indicate that schizophrenia is a complexly inherited disorder, whereby multiple genes, additively and in interaction with environmental factors, contribute to increasing risk for phenotypic expression. Linkage studies have identified a number of chromosomal regions as likely to harbor susceptibility genes for schizophrenia, but the linked regions span relatively large chromosomal segments in each case. These efforts have been hindered in part by a lack of means to detect nonpenetrant carriers of predisposing genes and in part by uncertainties concerning the nature of the nongenetic factors involved and their mechanisms of action in relation to genetic factors. Our strategy has focused on elucidating changes in central nervous system structure, physiology, and function that mark an inherited genotype for schizophrenia and on identifying specific environmental and etiological contributors and their modes of action in relation to genetic factors. The research reviewed in this paper, making use of family and twin designs, suggests that certain neural system deficits in schizophrenia (e.g., prefrontal cortex, working memory) are reflective of an inherited diathesis to the disorder, while others (e.g., temporal cortex, episodic memory) result from the interacting influences of genetic factors and particular types of biologically disruptive environmental events (e.g., fetal hypoxia). These findings help to reveal continuities and discontinuities in the neural disturbances characteristic of the schizophrenia genotype and phenotype and encourage the use of quantitative neural trait measures in the search for schizophrenia susceptibility genes.

Cognitive and brain function in schizotypal personality disorder

Schizotypal personality disorder, a diagnosis defined partially in terms of a genetic relatedness to schizophrenia, has begun to receive extensive investigative study. While the exact etiologic relationship between schizotypal personality disorder and schizophrenia remains to be determined, three models have been considered: (1) the two may be distinct disorders, (2) they may be essentially identical disorders but expressed with different degrees of severity, or (3) they may be related disorders with a partially overlapping etiology that might account for the many similarities yet the lack of psychosis or severe deficits in schizotypal individuals. Some of the recent research in the structural and functional neuroanatomy, neurochemistry, cognitive function, and pharmacology of schizotypal personality disorder is reviewed with citation of the most recent findings from our laboratory and others. Both schizotypal and schizophrenic subjects appear to show abnormalities in temporal lobe volume, but schizotypal subjects do not appear to show the volumetric decreases in frontal cortex that schizophrenic patients evidence. Abnormalities in thalamic nuclei parallel these findings-the pulvinar, which projects to temporal association and sensory cortices, is reduced in both disorders, but the mediodorsal nucleus, which projects extensively to the frontal cortex, is reduced in schizophrenic patients but not in schizotypal patients. Functional imaging studies suggest that there may be abnormalities in frontal activation in both disorders, but that schizotypal individuals can recruit alternative regions to accomplish tasks requiring frontal lobe activation that may help compensate. Imaging studies of the subcortex including FDG/PET imaging of metabolic activity during a verbal learning task, SPECT imaging studies which measure binding of IBZM and its displacement following amphetamine administration, and plasma HVA determinations following 2-deoxyglucose administration all suggest the possibility of relatively reduced dopaminergic subcortical activity in schizotypal individuals compared to schizophrenic patients. Cognitive function is also impaired in the areas of working memory, verbal learning, and attention in schizotypal patients, as in schizophrenic patients, and they may be particularly susceptible to cognitive tasks with high context dependence, as in schizophrenia. Preliminary trials of catecholaminergic agents suggest that these agents may be able to improve these impaired cognitive functions.

Neurocognitive functioning and schizophrenia spectrum disorders can be independent expressions of familial liability for schizophrenia in community control children: the UCLA family study

This study provided a further test of the hypothesis that certain neuromotor, language and verbal memory dysfunctions reflect genetic predisposition to schizophrenia, by examining the effects of family loading for schizophrenia (FLS) in normal controls without personal histories of schizophrenia or attention deficit hyperactivity disorder. In a case control design, 11 community controls (CC) with FLS were compared to 47 CC without FLS on tests of expressive and receptive language, visual motor coordination, full scale intelligence and verbal memory. In this study, FLS primarily reflects the incidence of schizophrenia spectrum diagnoses in the second-degree relatives of CC probands. CC probands with FLS had significantly poorer general intelligence, expressive and receptive vocabulary abilities, visual motor coordination and slower motor speed than CC probands without FLS. The variance in neurocognitive functioning associated with FLS is not due to the presence of any psychiatric disorders in CC probands, nor the presence of schizophrenia spectrum disorders in their parents. The relation between FLS and neurocognitive and neuromotor functioning in CC probands was moderated by the parent's cognitive functioning. The results of the present study indicate that familial liability to schizophrenia can be transmitted across two generations, independent of the presence of schizophrenia spectrum disorders in either the parent or proband, and account for significant variance in proband neurocognitive and neuromotor functioning. These findings suggest the neurocognitive and neuromotor functioning and schizophrenia spectrum disorders can be relatively independent expressions of familial liability to schizophrenia.

Lateralized perceptual organization deficits on the global-local task in schizotypal personality disorder

Right and left hemisphere contributions to perceptual organization functions were examined using a divided-attention version of the global-local task in a sample of 21 unmedicated participants diagnosed with schizotypal personality disorder (SPD) and 20 controls. The SPD participants showed an abnormal global processing advantage. When the visual angle of the hierarchical stimuli was increased from 3 degrees to 9 degrees, the controls showed an increasing local processing advantage, but the SPD participants continued to show an abnormal global processing advantage. These findings suggest a local processing deficit on divided-attention versions of the global-local task in schizophrenia spectrum disorders. Female SPD participants, who had less severe interpersonal deficit symptoms, showed a more abnormal global processing advantage. Hemispheric and processing resource mechanisms that might explain these findings are discussed.

Implicit memory in schizotypal subjects and normal controls: effects of a secondary task on sequence learning

Using a serial reaction-time task, the implicit memory performances of 29 high scoring (schizotypes) and 24 low scoring subjects (controls) on the German version of the 1997 Schizotypal Personality Questionnaire by Klein, Andresen, and Jahn were compared. To test the hypothesis that schizotypes show a differential deficit, subjects participated either in a single task condition of the serial reaction-time task or in a dual task condition of a secondary tone-counting task. Neither under single task conditions nor under dual task conditions did schizotypes show any impairment of implicit memory compared with controls. In addition, a separate analysis of the response latencies for the unique and ambiguous transitions of the repeated sequence did not indicate any differences between the two groups. These findings support and augment the results reported by Ferraro and Okerlund (1995).

Factor versus cluster models of schizotypal traits. II: relation to neuropsychological impairment

Heterogeneity in cognitive performance in schizophrenia and schizotypy may be accounted for, by differences in predominant symptom presentation. However, studies have not demonstrated consistent relations between specific cognitive impairments and specific trait dimensions in either population. Studies of group differences, particularly those using groups defined by cluster analyses are rare, but suggest that the negative trait dimension is more associated with executive function deficits, positive trait dimension with memory and attentional difficulties, and the disorganized trait dimension with attention problems. The present study examined the relation of schizotypal trait dimensions and executive function deficits in schizotypal individuals using two methods. Correlations between schizotypal factor scores and cognitive measures demonstrated that high negative symptoms were associated with poor performance on the WCST, while high scores on other trait dimensions were related to a better WCST performance. High scores in all trait dimensions were related to the naïve rater's observations of unusual social behavior. A cluster analysis revealed three groups of schizotypals (predominantly negative presentation, predominantly positive symptom presentation, and high on all dimensions). The cluster with predominantly negative symptoms performed worse, than all other schizotypal groups and unselected controls, on the WCST and a higher percentage of them were rated as clinically impaired on the neuropsychological battery. However, schizotypals who were high on all trait dimensions were rated as having the most unusual social behavior by the naïve raters. Overall, results support the hypothesis of a relation between executive function deficits and negative symptoms in schizotypal individuals.

Associations of P50 suppression and desensitization with perceptual and cognitive features of "unreality" in schizotypy

BACKGROUND

P50 suppression is an electrophysiologic index of early sensory gating and has consistently been found deficient in schizophrenic patients. This gating deficit is thought to lead to sensory overload and cognitive fragmentation, and correspondingly many symptoms of the disorder. However, the link between P50 suppression deficits and symptomatology is yet to be established, and so this study was designed to determine whether such a relation is present within a nonclinical population.

METHODS

P50 suppression and schizotypy measures were obtained from 36 healthy volunteers, and correlation analyses determined whether measures of schizotypy were related to P50 suppression.

RESULTS

Consistent with the view that P50 gating deficits are related to schizophrenic symptoms, subjects with poorer P50 suppression reported more perceptual anomalies and magical ideation--an unreality syndrome--in contrast to other positive symptoms and to withdrawal. This study also found a trend to P50 suppression desensitization, and that whereas subjects low on "unreality" demonstrated desensitization to the second of the paired clicks, subjects high on "unreality" demonstrated sensitization.

CONCLUSIONS

It is concluded that early sensory gating deficits, in the form of poor P50 suppression, are related to unreality aspects of schizotypy. This supports the view that poor P50 suppression in schizophrenia is related to symptomatology.

Pain insensitivity in the relatives of schizophrenia patients

The psychiatric literature contains anecdotal reports of diminished pain sensitivity in schizophrenia that date back to Kraepelin. Yet, the phenomenon of pain insensitivity in schizophrenia remains largely unstudied. For example, it is not clear if pain insensitivity is a consequence of the illness or if it is also present in the well relatives of schizophrenia patients. To explore this issue, we examined pain thresholds and pain tolerances in healthy young adults. Compared with controls with no family history of psychopathology (n=21), participants with a family history of schizophrenia (n=32) showed elevated pain thresholds and pain tolerances to finger pressure. Pain insensitivity was also significantly correlated with elevated scores on measures of self-referential thinking, magical ideation, and perceptual disturbances. Finally, a sizeable minority (19%) of well relatives of schizophrenia patients showed extreme pain insensitivity compared to other participants. The pattern of findings suggests that pain insensitivity may warrant further exploration as a potential marker of underlying liability to psychosis.

Unilateral olfactory perception and magical ideation

We assessed olfactory detection thresholds and discrimination abilities in 40 healthy right-handers (20 women and 20 men). All subjects were also required to complete the Magical Ideation (MI) scale, a well-validated 30-item schizotypy inventory. Over both nostrils, we found elevated thresholds for subjects with high MI scores (at or above the median score of 9.0) compared with those with low scores. In men but not women, specifically left-nostril acuity was inversely correlated to MI raw scores. MI was unrelated to olfactory discrimination performance. These results suggest an association, at least in healthy men, between even moderate signs of schizotypy and deficits in odor detection. The selective impairment of left-nostril performance adds to the growing evidence for left temporal lobe functional abnormalities in people high on MI. This laterality effect is known from previous studies in patients with schizophrenia. However, as a rule, in psychiatric patients olfactory identification rather than simple detection performance was found to be impaired, indicating that the integration of odor information is affected at different levels of processing in schizotypy compared with schizophrenia. Work with completely normal subjects may reasonably complement clinical studies of olfactory perception. Among its advantages are the good subject compliance and the absence of medication effects.

Is the attentional dysfunction in schizotypy related to anxiety?

Two factors, 'anxiety-loaded' (AL) and 'perceptual-disorganization' (PD), emerged in a factor analysis of the Schizotypal Personality Questionnaire (SPQ). Sixty of the 219 participants performed a latent inhibition (LI) task. During the pre-exposure phase, one group was exposed to repeated non-reinforced presentations of an irrelevant stimulus and the other was not pre-exposed. In the subsequent test phase, learning was slower in the pre-exposed group than in the non-pre-exposed group. The LI effect was assessed, separately, as a function of SPQ, trait-anxiety sub-scale (TASS) of the State and Trait Anxiety Inventory (STAI), and AL and PD factors scores. LI was disrupted in participants with either high scores on SPQ, STAI, or the AL factor. A regression analysis indicated that both TASS and SPQ independently accounted for LI disruption in high schizotypals, but that the contribution of TASS was stronger. It was suggested that the anxiety component of schizotypy, more than the perceptual-disorganization (schizophrenia-like) component, accounts for the attentional dysfunction in high schizotypals, and for their greater than normal distraction by irrelevant stimuli.

Saccadic eye movement abnormalities in relatives of patients with schizophrenia

Recent studies note abnormalities in saccadic eye movements of relatives of patients with schizophrenia. The current study examined which aspects of the saccadic system are affected, whether these saccadic abnormalities are associated with schizophrenia spectrum personality symptoms (SSP), and whether such an association is dependent on a family history of schizophrenia. Furthermore, the study examined what proportion of relatives have the saccadic abnormality(ies). Fifty-five first-degree relatives with no DSM-III-R Axis I diagnosis participated in the study. Twenty-one of these relatives experienced SSP symptoms and 34 had no Axis II diagnosis. Sixty-two subjects with no Axis I diagnosis were recruited from the community. Twenty-five experienced SSP symptoms and 37 had no Axis II diagnosis. Prosaccades (saccades toward the target) and antisaccades (saccades made in the opposite direction of the target jump) were examined. Relatives, particularly those with SSP, had difficulties with the antisaccade task as suggested by higher error rates and longer antisaccade latency. Prosaccades were not different in relatives compared to the community subjects, although the effects of field were different in the two groups on some measures. The antisaccade latency was 'abnormal' in only a small proportion (1.6%) of community subjects compared to 14.9% of all relatives (35.3% of SSP relatives and 3.3% of non-SSP relatives). Relatives of patients with schizophrenia have deficits in aspects of the saccadic system involved in generating internally driven saccades and inhibition of unwanted saccades. These deficits implicate frontal ocular motor neuronal circuitry involving frontal cortical and basal ganglia areas. These deficits are associated with SSP symptoms, but not in the absence of a blood relationship to schizophrenia. The relatively high prevalence rate of the abnormality in at-risk subjects may have relevance for use of these measures in linkage analysis.

Shape and size of the corpus callosum in schizophrenia and schizotypal personality disorder

The size and shape of the corpus callosum were assessed on sagittal section magnetic resonance images in 27 patients with schizophrenia, 13 patients with schizotypal personality disorder (SPD), and 30 healthy volunteers. High-resolution 1.2mm axial SPGR images were acquired and resectioned so that the sagittal plane passed through the anterior and posterior commissures and was parallel to the interhemispheric fissure. The corpus callosum and the whole brain were traced on midsagittal section slices of each brain, and the callosum was divided into 30 anteroposterior sectors. Pixel-by-pixel chi-square and thin-plate spline analyses were used to assess between-group shape differences. Size of the corpus callosum was smaller anteriorly in the genu of the corpus callosum and posteriorly in the splenium in schizophrenic patients than in normal controls. The genu of the corpus callosum was larger in SPD patients than in schizophrenic patients or normal controls. The posterior corpus callosum was largest in normal controls, smaller in SPD patients, and smallest in schizophrenic patients. Shape analysis was consistent with these size comparisons, and suggested a downward bowing of the corpus callosum in schizophrenic and SPD patients. SPD patients also had a region of the callosum just posterior to the genu that was narrower than in the other two groups. The decreases in corpus callosal size in schizophrenia varied directly with length of illness, perhaps indicative of a progressive process. The patient-control differences in callosal size and shape are consistent with a hypothesis of decreased connectivity between the left and the right hemispheres in schizophrenia and SPD.

Auditory working memory and verbal recall memory in schizotypy

Deficits on verbal memory tasks, as well as on spatial and auditory working memory tasks, have been observed in schizophrenia patients. A useful strategy in the determination of the premorbid indicator status of specific cognitive and memory deficits observed in patients is to examine those persons at increased biological risk for schizophrenia (e.g. first-degree relatives), schizotypal personality disorder patients, and/or psychometrically identified schizotypes for comparable deficits, though perhaps less profound than those seen in actual patients. We examined verbal memory and auditory working memory functioning in 31 schizotypic and 26 normal control subjects from a large randomly ascertained non-clinical university population. Schizotypy status was determined psychometrically using the well-known Perceptual Aberration Scale. Contrary to our theory-guided expectations, noteworthy deficits in verbal memory and auditory working memory were not observed in the schizotypic subjects and the two experimental groups did not differ significantly on any of the memory measures. These results were discussed in light of prior results obtained using the spatial delayed response task (i.e. spatial working memory) and Wisconsin Card Sorting Test performance on these same subjects. The theoretical implications of these findings are discussed in relation to the putative processes involved in the working memory system, as well as in relation to the schizotypy construct.

Two-point discrimination thresholds and schizotypy: illuminating a somatosensory dysfunction

The current study sought to determine if somatosensory deviations, assessed by determining two-point discrimination thresholds, were associated with schizotypic features in non-psychotic subjects (N=100). It was hypothesized that elevated two-point discrimination thresholds would be associated with an increased likelihood of higher levels of schizotypy features. The results of the study suggested that at the level of individual differences, higher two-point discrimination thresholds (ascending series assessments) were associated with higher levels of schizotypy as operationalized by several prominent measures of schizotypy. A deviant subgroup analysis clearly suggested that, for ascending series two-point threshold assessments, those persons requiring the greatest distance (i.e. highest thresholds) to detect two-point stimulation were substantially more schizotypic than a contrast group. Control analyses that focused on psychological state (depression, anxiety) and intellectual functioning variables revealed that these factors were, more or less, unrelated to two-point discrimination thresholds and they did not account for the observed significant relations between the schizotypy scales and two-point threshold values. The results of this study are discussed within a neuropsychological context implicating parietal cortex involvement with schizotypy and schizophrenia.

Executive functions in adolescents with schizotypal personality disorder

Adolescents meeting diagnostic criteria for schizotypal personality disorder (SPD) are presumed to be at risk for developing schizophrenia in adulthood, making them an important group for exploring the developmental trajectory of the disease. Deficits in executive functioning have been documented in schizophrenia patients and adults with SPD. The present study examined executive functions in adolescents with SPD. It was predicted that the SPD group would score below comparison groups (normals and adolescents with other disorders) on measures of executive function, and that those with greater 'negative' signs of SPD would show more pronounced performance deficits. Analyses revealed that the performance of the SPD subjects was impaired relative to the other groups on the modified Wisconsin Card Sorting Test (MCST), but not on the Tower of London or the Controlled Oral Word Association Test. Consistent with prediction, regression analyses indicated that MCST deficits were associated with greater negative signs of SPD, but not positive signs.

Co-occurrence of Axis I and Axis II disorders in substance abusers

OBJECTIVE

This study examined the co-occurrence of anxiety/mood and personality disorders (PDs) in substance abusers, the impact of anxiety/ mood disorders on the symptom profiles of PDs, and the impact of anxiety/mood disorders and PDs on pre-treatment status.

METHOD

Current anxiety/mood disorders and PDs and pre-treatment status were assessed using semi-structured interviews in 370 treated substance abusers.

RESULTS

Anxiety/mood disorders and PDs frequently co-occurred, with the overall pattern of associations being non-specific. The strongest associations were of social phobia with avoidant and schizotypal PD, and of major depression with borderline PD. However, symptom profiles of PDs were not associated with anxiety/mood disorders. Finally, anxiety/mood disorders and PDs were both independently and differentially associated with poor pre-treatment characteristics.

CONCLUSION

The findings suggest the clinical importance of obtaining both Axis I and Axis II diagnoses in treated substance abusers, and highlight the distinctiveness of the Axis I and Axis II disorders.

Associations of self-reported past "psychotic" phenomena with features of personality disorders

Patients with borderline personality disorder (BPD) may present with "psychotic" phenomena, which can be defined as a range of specified "altered experiences of reality." This study investigated the associations between self-reported past psychotic phenomena and features of DSM-III-R personality disorders (PDs) in 57 inpatients without a previous diagnosis of the main disorders that involve delusions and hallucinations. The present findings include associations between past psychotic phenomena and features of BPD, between repeated self-harm and a report that "thoughts seemed put into head," and between psychotic phenomena and features of other PDs, particularly schizotypal PD. There was a high prevalence of BPD in the present sample. Dissociation, in the context of the features of BPD, may be a causal factor for the development of some of the psychotic phenomena presented by patients with PD.

Evidence of a schizotypy subtype in OCD

OCD patients represent a heterogeneous mix of clinical phenotypes, likely reflecting a wide range of genetic vulnerabilities. In other medical illnesses, neurobiologically-based traits with a genetic component that are associated with the target disorder have been successfully used to detect patients with a specific genetic liability to disease. The overlap between symptoms of OCD and Schizophrenia suggested that schizotypal traits could have the potential to distinguish a relatively homogeneous subtype of OCD. We obtained schizotypy scores for 119 affected adult probands who met lifetime criteria for DSM-IV OCD. Five subscales from the Structured Interview of Schizotypy were used to assess ideas of reference, suspiciousness, magical thinking, illusions and psychotic-like thought. Selected for their obvious face validity with the cardinal signs of schizophrenia, Cronbach's alpha suggested that these subscales also provided a reliable measure of positive sign schizotypy (0.83). Fifty percent of our OCD sample had mild to severe positive schizotypy signs. t- and chi2 tests of significance suggested seven variables that distinguished OCD patients with schizotypy, including earlier age of onset, greater number of comorbid diagnoses and increased rates of learning disability, aggressive and somatic obsessions and counting and arranging compulsions. Three of these seven variables, including learning disabilities, counting compulsions and history of specific phobia, significantly increased the odds of schizotypy among patients with lifetime OCD. These findings enhanced the validity of the schizotypy construct in OCD. Whether this schizotypy subtype can distinguish a subgroup of patients with relatively homogeneous genetic characteristics waits further investigation.

Motor dysfunction and risk for schizophrenia

Motor dysfunction is associated with schizophrenia, and recent longitudinal studies indicate that it precedes the onset of clinical symptoms. Of particular interest is the heightened occurrence of involuntary movements, which are apparent as early as infancy and suggest the presence of subcortical brain abnormalities. In this article, we present the results of a study of spontaneous movements in adolescents with schizotypal personality disorder (SPD). SPD is a syndrome that has been shown to be genetically linked with schizophrenia and is often observed prior to the early adult onset of schizophrenia. Systematic coding of videotapes of diagnostic interviews revealed that the SPD group showed significantly more involuntary movements of the head, trunk, and upper limbs than did normals and adolescents with other personality disorders. There were no diagnostic group differences in the rate of voluntary movements. Salivary cortisol, measured before the interview, was positively correlated with involuntary movements. Taken together, the findings provide further support for the hypothesized etiologic relation between SPD and schizophrenia. Based on a neural diathesis-stress model, potential underlying mechanisms are discussed.

Motor dysfunction in schizotypal personality disorder

Past research has revealed that schizophrenia is associated with voluntary movement abnormalities, as well as higher rates of involuntary movements. On instrumental motor tasks, patients manifest reduced motor stability, excessive force and more contralateral motor overflow (movement in the non-responding hand). In the present study, an instrumental motor task (manual response forced-choice task) was administered to a group of adults with schizotypal personality disorder (SPD) in order to determine whether they show motor deficits similar to those observed in schizophrenia. As predicted, the schizotypal subjects were excessive and more variable in motor force, compared to healthy controls and other personality-disordered subjects. Additionally, the force and variability of the motor responses were positively correlated with ratings of both positive and negative SPD symptoms. Finally, motor overflow and negative symptoms were associated with higher salivary cortisol levels. The pattern of findings is consistent with previous reports linking motor abnormalities and heightened cortisol with schizotypal personality disorder.

Neurological soft signs in adolescents with poor performance on the continous performance test: markers of liability for schizophrenia spectrum disorders?

There is much evidence that neurological soft signs (NSS) are highly prevalent in both adults and children with schizophrenia. In addition, they have been detected as early precursors of a schizophrenic outcome in at-risk subjects. Such findings point to the possible value of NSS as neurointegrative markers in schizophrenia which has been hypothesized to be a neurodevelopmental disease. In our study we used a biobehavioral criterion to select the 'at-risk' group, a sustained attentional deficit as measured by the continuous performance test (CPT). We compared 140 normal adolescents with 162 'CPT-linked vulnerable' adolescents (index subjects) on a battery for the assessment of NSS (including laterality), IQ, frontal lobe function and schizotypy. An association was found between NSS and attentional deficit. Furthermore, index subjects with NSS were characterized by lower IQ scores, poorer performance on frontal lobe tests and greater problems with social interaction. There was also a trend for an association between male sex and both left-handedness and NSS.