Children with a schizophrenic disorder: neurobehavioral studies

Early-onset schizophrenia: studying the links between cognitive and clinical dimensions

BACKGROUND

Early-onset schizophrenia (EOS), a rare and severe chronic psychiatric condition, is defined by an onset of schizophrenia symptoms before the age of 18. Core symptoms also include cognitive impairments. However, little is known about links between psychiatric symptoms of EOS and cognitive abilities.

OBJECTIVE

To explore the clinical and neurocognitive profiles of EOS patients and their links.

METHOD

EOS patients have been phenotyped using standardised psychiatric assessments for DSM-5 diagnoses (K-SADS-PL) and for symptoms (PANSS and SANS), together with neurocognitive evaluations.

RESULTS

The EOS sample (n = 27, 12.4 +/-3.2 years) presented hallucinations (83%), negative symptoms (70%) and delusion (59%). 81% of patients presented comorbidities such as anxiety disorders (33%), autism spectrum disorder (26%) and attention-deficit hyperactivity disorder (26%). Patients presented borderline intellectual deficiency (total IQ = 72.5 +/-4.7), with low performances in working memory subtest. We highlight a positive correlation between the IQ and intensity of positive symptoms (PANSS) and between the IQ and a first treatment being administered at an older age. We also highlight a negative correlation between the IQ and attention items of SANS.

CONCLUSION

Cognitive skills are correlated with symptom intensity in EOS patients. An older age of onset seems to be a protective factor for cognitive development.

Impaired automatization of a cognitive skill in first-degree relatives of patients with schizophrenia

We studied healthy, first-degree relatives of patients with schizophrenia to test the hypothesis that deficits in cognitive skill learning are associated with genetic liability to schizophrenia. Using the Weather Prediction Task (WPT), 23 healthy controls and 10 adult first-degree Relatives Of Schizophrenia (ROS) patients were examined to determine the extent to which cognitive skill learning was automated using a dual-task paradigm to detect subtle impairments in skill learning. Automatization of a skill is the ability to execute a task without the demand for executive control and effortful behavior and is a skill in which schizophrenia patients possess a deficit. ROS patients did not differ from healthy controls in accuracy or reaction time on the WPT either during early or late training on the single-task trials. In contrast, the healthy control and ROS groups were differentially affected during the dual-task trials. Our results demonstrate that the ROS group did not automate the task as well as controls and continued to rely on controlled processing even after extensive practice. This suggests that adult ROS patients may engage in compensatory strategies to achieve normal levels of performance and support the hypothesis that impaired cognitive skill learning is associated with genetic risk for schizophrenia.

The ontogeny of learned inhibition

Previous studies have examined the maturation of learning and memory abilities during early stages of development. By comparison, much less is known about the ontogeny of learning and memory during later stages of development, including adolescence. In Experiment 1, we tested the ability of adolescent and adult rats to learn a Pavlovian negative occasion setting task. This procedure involves learning to inhibit a behavioral response when signaled by a cue in the environment. During reinforced trials, a target stimulus (a tone) was presented and immediately followed by a food reward. On nonreinforced trials, a feature stimulus (a light) was presented 5 sec prior to the tone and indicated the absence of reward following presentation of the tone. Both adult and adolescent rats learned to discriminate between two different trial types and withhold responding when the light preceded the tone. However, adolescent rats required more sessions than adults to discriminate between reinforced and nonreinforced trials. The results of Experiment 2 revealed that adolescents could learn the task rules but were specifically impaired in expressing that learning in the form of withholding behavior on nonreinforced trials. In Experiment 3, we found that adolescents were also impaired in learning a different version of the task in which the light and tone were presented simultaneously during the nonreinforced trials. These findings add to existing literature by indicating that impairments in inhibitory behavior during adolescence do not reflect an inability to learn to inhibit a response, but instead reflect a specific deficit in expressing that learning.

Practitioner review: schizophrenia spectrum disorders and the at-risk mental state for psychosis in children and adolescents--evidence-based management approaches

BACKGROUND

Schizophrenia spectrum disorders are severe mental illnesses which often result in significant distress and disability. Attempts have been made to prospectively identify and treat young people viewed as at high risk of impending nonaffective psychosis. Once a schizophrenia spectrum disorder has developed, prompt identification and management is required.

METHODS

This article reviews the literature relating to the assessment and management of 'at-risk mental states' (ARMS) and the treatment of schizophrenia spectrum disorders in children and adolescents. A systematic search of the literature was undertaken using EMBASE, MEDLINE, PsycINFO databases for the period January 1970-December 2012.

RESULTS

Evidence suggests that young people fulfilling the ARMS criteria are at high risk of adverse mental health outcomes but that the majority do not develop nonaffective psychosis over the medium term. Although clinical trial findings have been inconsistent, psychosocial approaches, such as cognitive behaviour therapy, may reduce the risk of transition to psychosis and improve some symptoms, at least over the short term. The effectiveness of psychotropic medication for the ARMS is uncertain although there is accumulating evidence for potential adverse effects of antipsychotic medication, even at low dose, in this population. For the schizophrenias, clinical trial findings suggest that, as in adults, antipsychotics should be selected on the basis of side-effect profile although clozapine may be helpful in treatment refractory illness. There are almost no studies of psychosocial treatments for schizophrenia in young people under 18, and some caution must be exercised when extrapolating the findings of adult studies to younger individuals.

CONCLUSIONS

A stepped care approach to the ARMS in young people represents a plausible potential management approach for those at high risk of serious mental health problems. However, predictive models currently lack precision and should focus on accurately identifying those at high risk for a variety of poor outcomes who may benefit most from intervention. There is also an urgent need for age-specific research in the area of psychosocial treatments for children and adolescents with schizophrenia.

Psychosis in children: diagnosis and treatment

The diagnosis of childhood psychosis raises a host of unresolved problems, despite the Diagnostic and Statistical Manual Of Mental Disorders, 4th edition, Text Revision (DSM-IV-TR) giving identical symptoms and definitions for children, adolescents, and adults. The fantasy lives of children, and issues of developing language and cognition (including retardation), all impair diagnostic accuracy, particularly when differentiating between childhood-onset schizophrenia (COS) (≤12 years), bipolar affective disorder, major depressive disorder, and even obsessive-compulsive disorder and attention-deficit/hyperactivity disorder: the catch-all classification, psychosis not otherwise specified (PNOS), is always available for conundra that prove unsolvable. Typical if nonpathognomonic features include neurocognitive difficulties. Multiple screening instruments and specialized versions of semistructured diagnostic interviews are available. Although smooth-pursuit eye-tracking movements may prove a genetic marker for COS, etiologies are likely to be oligogenetic rather than related to a single gene. No specific biological markers or neuroimages have been identified. As such, psychoses may be indicative of a more general pattern of brain dysfunction. Drug treatments are largely based on the adult literature because of a dearth of controlled data below age 18. There are still no rigorous studies of psychosocial treatments and psychotherapy specific to childhood psychosis.

Finding behavioral and network indicators of brain vulnerability

Resilience research has usually focused on identifying protective factors associated with specific stress conditions (e.g., war, trauma) or psychopathologies (e.g., post-traumatic stress disorder [PTSD]). Implicit in this research is the concept that resilience is a global construct, invariant to the unfavorable circumstances or the psychopathologies that may develop (i.e., the mechanisms underlying the resilience of an individual in all cases are expected to be similar). Here we contribute to the understanding of resilience—and its counterpart, vulnerability—by employing an approach that makes use of this invariant quality. We outline two main characteristics that we would expect from indicators of a vulnerable state: that they should appear across disorders regardless of specific circumstances, and that they should appear much before the disorder is evident. Next, we identify two sets of factors that exhibit this pattern of association with psychopathological states. The first was a set of “low-level” sensory, motor and regulatory irregularities that have been reported across the clinical literature; we suggest that these can serve as behavioral indicators of a vulnerable state. The second was the set of aberrations in network metrics that have been reported in the field of systems neuroscience; we suggest that these can serve as network indicators of a vulnerable state. Finally, we explore how behavioral indicators may be related to network indicators and discuss the clinical and research-related implications of our work.

From bench to bedside: translating new research from genetics and neuroimaging into treatment development for early-onset schizophrenia

OBJECTIVE

Children and adolescents with schizophrenia share a similar pattern of phenomenological, genetic and cognitive abnormalities to adults with schizophrenia. However, an early-onset of schizophrenia (EOS) (prior to 18 years of age) is associated with a higher frequency of risk indicators associated with schizophrenia (e.g. developmental delays and familial spectrum disorders) and a worse long-term outcome. This overview examines recent research on the neurobiological alterations, possible causes, developmental trajectory and treatment of EOS and attempts to identify gaps in the field.

METHOD

The authors provide a selective review of major findings from genetics, neuroimaging and treatment studies of pediatric schizophrenia that were presented at a workshop sponsored by the National Institute of Mental Health. These data are synthesized in conjunction with preclinical studies into a model of the pathophysiology of EOS.

RESULTS

EOS is associated with a high frequency of cytogenetic abnormalities (e.g. velocardiofacial syndrome, sex chromosome anomalies) and other rare denovo chromosomal aberrations. Brain imaging research in adolescents with EOS has revealed a progressive loss of cortical grey matter post-onset of psychosis and subtle abnormalities in white matter microstructure. Although EOS patients are more likely to be treatment-refractory than their adult counterparts, there are substantial data that this subgroup is particularly responsive to clozapine.

CONCLUSIONS

Genetic or environmental factors operating during adolescence that reduce frontal capacity might contribute to an EOS in susceptible individuals. Additional longitudinal studies of adolescents with schizophrenia are needed to better understand the relationship between structural changes in fronto-limbic regions, stress responsivity, and cognitive and neurochemical development.

A novel syndrome with psychiatric features and review of malformation syndromes with psychiatric disorders

Psychiatric disease occurs with increased frequency in a number of malformation syndromes. We hypothesize that the study of these disorders is helpful for understanding the pathophysiology of psychiatric disease. With this objective, we have been screening for individuals with malformations and prominent psychiatric disease. We report on a man with visual and auditory hallucinations and behavioral problems who was the product of an incestuous relationship and had anomalies primarily of his face, hands and feet. His distinctive features define an undescribed acro-auricular malformation syndrome with a psychiatric component. The study of Mendelian syndromes such as the one presented will likely be helpful for isolating novel genes involved in psychiatric illness.

Efficacy and tolerability of second-generation antipsychotics in children and adolescents with schizophrenia

Early-onset schizophrenia-spectrum (EOSS) disorders (onset of psychotic symptoms before 18 years of age) represent a severe variant associated with significant chronic functional impairment and poor response to antipsychotic treatment. All drugs with proven antipsychotic effects block dopamine D(2) receptors to some degree. The ongoing development of the dopamine and other neurotransmitter receptor systems during childhood and adolescence may affect clinical response and susceptibility to side effects in youth. A literature search was conducted of clinical trials of antipsychotics in children and adolescents with EOSS disorders between 1980 and 2007 from the Medline database, reference lists, and conference proceedings. Trials were limited to double-blind studies of duration of 4 or more weeks that included 15 or more patients. Ten clinical trials were identified. Antipsychotic medications were consistently found to reduce the severity of psychotic symptoms in children and adolescents when compared with placebo. The superiority of clozapine has been now demonstrated relative to haloperidol, standard-dose olanzapine, and "high-dose" olanzapine for EOSS disorders. However, limited comparative data are available regarding whether there are differences among the remaining second-generation antipsychotics (SGAs) in clinical effectiveness. The available data from short-term studies suggest that youth might be more sensitive than adults to developing antipsychotic-related adverse side effects (eg, extrapyramidal side effects, sedation, prolactin elevation, weight gain). In addition, preliminary data suggest that SGA use can lead to the development of diabetes in some youth, a disease which itself carries with it significant morbidity and mortality. Such a substantial risk points to the urgent need to develop therapeutic strategies to prevent and/or mitigate weight gain and diabetes early in the course of treatment in this population.

Inhibitory control in children with autism spectrum disorder

Impairments in executive abilities such as cognitive flexibility have been identified in individuals with autism spectrum disorder (ASD). It remains unclear, however, whether such individuals also experience impairments in another executive ability: inhibitory control. In the present study, we administered three inhibitory tasks to 18 children with ASD, 23 siblings of children with ASD, and 25 typically developing children. After controlling for individual differences in age, overall IQ, and processing speed, children with ASD demonstrated impaired performance on two of the three inhibitory tasks. Results suggest that children with ASD experience circumscribed deficits in some but not all aspects of inhibitory control. More generally, the findings underscore the importance of using multiple measures to assess a putative single cognitive ability.

Inhibitory control in children with phenylketonuria

Past studies have reported impairments in children with early-treated phenylketonuria (PKU) in executive abilities such as strategic processing and working memory. Findings have been inconsistent in terms of the integrity of inhibitory control, another executive ability. This study administered 4 inhibitory tasks (flanker, Stroop, go/no-go, antisaccade) to 26 children with PKU and 25 typically developing control children. Children with PKU performed more poorly than typically developing children on the 2 inhibitory tasks with the strongest experimental manipulations (go/no-go and antisaccade) between control and inhibitory conditions. Findings suggest that the inhibitory deficit associated with PKU is subtle and that inconsistent findings in past studies may be largely due to the insensitivity of experimental manipulations in some tasks.

Comparative study of neuropsychological correlates in schizophrenia with onset in childhood, adolescence and adulthood

Childhood onset schizophrenia (COS) patients have marked neuropsychological deficits in areas of attention, working memory and executive functions. Similar deficits have been found in studies on Adolescent onset (AdOS) and Adult onset schizophrenia (AOS). In this study we compared the neuropsychological profile of COS with AdOS and AOS to test the hypothesis that earlier the onset greater is the severity of illness and greater are the neuropsychological deficits. A sample of 15 patients of COS was compared with 20 patients each of AdOS and AOS group. Assessment of neuropsychological profile was done using standard neuropsychological battery for Indian population. Nahor Benson Test and Bender Visual Motor Gestalt Test were used to assess perceptuomotor functioning. COS patients showed significantly greater deficits on scales of IQ, memory and perceptuomotor skills as compared to AdOS that in turn had greater deficits than AOS. The persistence of differences across the three groups inspite of controlling for education and age suggest that these deficits may have been present even before the onset of illness and was not the result of poor academic achievements. These findings also point towards a brain damage in schizophrenia that occurs on a continuum of severity with COS being the most virulent, AOS being the least and AdOS falling in between these two extremes.

Premorbid factors in relation to motor, memory, and executive functions deficits in adult schizophrenia

This study examined two areas of premorbid adjustment (attentional functioning and social adaptation) and three areas of adult neuropsychological performance (executive functions, learning/memory, and motor functions) in a clinically stable outpatient sample of schizophrenics (n=61). The study examined three components of premorbid attentional functioning (concentration, hyperactivity, and requiring supervision for organizing activities or tasks) and three components of premorbid social adaptation (socialization skills, disciplinary problems, and antisocial behavior) in relation to the neuropsychological variables assessed in adulthood. Findings indicated that premorbid difficulties in all three attentional functioning areas and two of the three social functioning areas were related to adult neuropsychological performance. Childhood concentration deficits were not as significant an influence as distractibility on adult neuropsychological functioning, nor was excessive premorbid activity level as important as inhibiting impulsivity. Premorbid socialization deficits were related to motor dysfluency in adulthood. A history of disciplinary problems but not antisocial behavior in childhood had an adverse influence on adult neuropsychological deficits. This study demonstrated selective influences of premorbid attentional and social adjustment impairments on a broad range of cognitive abilities in adult schizophrenia.

Clinical, imaging, lesion, and genetic approaches toward a model of cognitive control

The ability to suppress or override competing attentional and behavioral responses is a key component of cognitive processes. This ability continues to develop throughout childhood and appears to be disrupted in a number of childhood disorders (e.g., attention deficit/hyperactivity disorder and Tourette syndrome). At least two brain regions have been implicated repeatedly in these disorders--the frontal lobes and the basal ganglia. The common problem in cognitive control and overlap in implicated brain regions across disorders suggest a single underlying biological mechanism. At the same time, the distinct symptomatology observed across these disorders suggests multiple mechanisms are at play. This article presents converging evidence from clinical, neuroimaging, lesion, and genetic studies to provide a mechanistic model of cognitive control whereby the basal ganglia are involved in inhibition of competing actions and the frontal cortex is involved in representing the relevant thoughts and guiding the appropriate behaviors.

Childhood-onset schizophrenia: research update

This review is a research update of recent literature related to childhood-onset schizophrenia (onset of psychotic symptoms by age 12 years). This subgroup of patients has attracted considerable research interest because patients with a childhood onset may represent a more homogeneous patient population in which to search for risk or etiologic factors. We examine data indicating that childhood-onset schizophrenia (COS) shares the same clinical and neurobiologic features as later-onset forms of the disorder. Compared with adults with schizophrenia, however, this subgroup of patients appears to have more severe premorbid neuro-developmental abnormalities, more cytogenetic anomalies, and potentially greater family histories of schizophrenia and associated spectrum disorders. While preliminary, these data indicate that a greater genetic vulnerability may be one of the underpinnings of COS. Future studies of this subgroup may provide important clues as to the genetic basis for schizophrenia and how gene products influence certain features of the disease, such as age of onset and mode of inheritance.

Thought disorder in attention-deficit hyperactivity disorder

OBJECTIVE

This study compared thought disorder and associated cognitive variables in attention-deficit hyperactivity disorder (ADHD) and schizophrenia.

METHOD

Speech samples of 115 ADHD, 88 schizophrenic, and 190 normal children, aged 8 to 15 years, were coded for thought disorder. A structured psychiatric interview, the WISC-R, the Continuous Performance Test, and the Span of Apprehension task were administered to each child.

RESULTS

The ADHD and schizophrenic groups had thought disorder compared with the normal children. However, the subjects with ADHD had a narrower range of less severe thought disorder than did the schizophrenic subjects. The younger children with ADHD and schizophrenia had significantly more thought disorder than did the older children with these diagnoses. IQ, attention, and working memory were associated with thought disorder in the ADHD but not the schizophrenic group.

CONCLUSIONS

Thought disorder in childhood is not specific to schizophrenia and reflects impaired development of children's communication skills.

Brain abnormalities observed in childhood-onset schizophrenia: a review of the structural magnetic resonance imaging literature

Childhood-onset schizophrenia (COS) is a rare, severe form of schizophrenia in which there are structural brain abnormalities that may be related to the psychotic symptomatology and neurocognitive deficits found in these patients. While there are numerous structural imaging studies of the adult-onset variant of schizophrenia (with many conflicting findings), relatively few brain imaging studies of COS have been conducted. This paper summarizes the extant literature of magnetic resonance imaging (MRI) studies of structural brain abnormalities in COS, and compares findings to similar studies of adult-onset patients. Volumetric MRI studies of COS patients have consistently shown evidence for increased ventricular volume, reduced cerebral gray matter, and increased caudate volume, consistent with findings from adult-onset studies. Other volumetric brain abnormalities are observed in COS patients, such as reduced total brain volume, but not consistently across all studies. Voxel-based morphometric analyses have revealed abnormalities in the shape and spatial location of structures in COS such as the corpus callosum, caudate, and thalamus that could not be observed in the more traditional volumetric assessments. Similar findings also are observed in adult-onset patients. Progressive degenerative changes, such as ventricular enlargement, appear to occur in COS only until young adulthood where there is an apparent asymptote with no further degenerative changes. This is consistent with the lack of progressive changes noted in most longitudinal studies of adult-onset schizophrenia.

Neuropsychological deficits in pediatric patients with childhood-onset schizophrenia and psychotic disorder not otherwise specified

OBJECTIVE

Children with transient psychotic symptoms and serious emotional disturbances who do not meet current criteria for schizophrenia or other presently recognized diagnostic categories commonly present diagnostic and treatment problems. Clarifying the connections between children with narrowly defined schizophrenia and children with a more broadly defined phenotype (i.e., Psychotic Disorder Not Otherwise Specified, PD-NOS) has implications for understanding the pathophysiology of schizophrenia. In this study, the neuropsychological test performance of a subgroup of children with atypical psychosis was compared with that of patients with childhood-onset schizophrenia (COS).

METHOD

Cognitive function was assessed with neuropsychological test battery regimens in 51 neuroleptic-nonresponsive patients within the first 270 at NIMH testing (24 PD-NOS, 27 COS) were included in this analysis. Seventeen (39%) of 44 COS subjects were unavailable for this study as their IQ tested <70. The PD-NOS patients were younger than the COS patients at the time of testing (12.0+/-2.8 vs 14.4+/-1.8years, respectively, p<0.004). The test levels of these groups were compared with each other.

RESULTS

The neuropsychological test results for the PD-NOS and COS patients were 1-2standard deviations below normative data across a broad array of cognitive functions. There were no overall differences in the test levels for the six summary scales (F=2.82, df=1, 36, p=0.10) or in the profile shape (F=1.70, df=5, 180, p=0.14) between the PD-NOS and COS groups. For the COS patients, there was a significant difference between their mean full-scale WISC IQ (84.7+/-16.2) and their average standard scores for both the spelling (97.7+/-16.1, n=23, t=4.0, p=0.001) and reading decoding subtests (97.7+/-13.7, n=23, t=3.7, p=0.001) of the Kaufman Test of Educational Achievement.

CONCLUSIONS

Treatment-refractory PD-NOS and COS patients share a similar pattern of generalized cognitive deficits, including deficits in attention, learning and abstraction which are commonly observed in adult patients with schizophrenia. These data support a hypothesis that at least some of the PD-NOS cases belong within the schizophrenic spectrum, which is of importance for future genetic studies planned for this cohort.

Schizophrenia with onset before the age of eleven: clinical characteristics of onset and course

This study reports on the long-term course of 11 patients (6 girls, 5 boys) with childhood onset schizophrenia (COS, age at onset < 10 years). Patients were examined twice (mean follow-up period 38 years after onset). The premorbid development is assessed in terms of the Modified Premorbid Adjustment Scale (M-PAS) and additionally described by distinct psychopathological categories. The psychopathology at the onset of psychosis and at the second follow-up examination was assessed by categorical application of the Positive and Negative Syndrome Scale (PANSS). The outcome was rated with the Disability Assessment Score (DAS). The course of psychotic episodes and intervals between them is presented according to DSM-IV subtype classifications. Ten of 11 patients presented premorbid developmental peculiarities that were not adequately covered by the M-PAS subscales. Whereas in the 4 patients with acute onset of psychosis the positive PANSS-type was predominant, in the 7 patients with an insidious onset the negative PANSS-type prevailed. The nature of the diagnostic subtypes varied markedly across the course of the illness. In case of a continuous predominant catatonic symptomatology the outcome was poor. Detailed case descriptions help to illuminate the heterogeneous psychopathology of COS. Various temporary premorbid behavioral peculiarities were precursors of COS. A differentiation between premorbid and prodromal signs proved to be arbitrary. Our results contradict the assumption that COS is characterized only by a negative symptomatology.

The ESSEN study of childhood-onset schizophrenia: selected results

INTRODUCTION

We present the results of a 42 year long-term follow-up of 44 patients (19 males, 25 females) with childhood-onset schizophrenia (COS, age at onset: 7-14 years) who could be traced for a second follow-up examination 27 years after the first follow-up.

METHOD

Data from interviews, clinical records, premorbid and social disability assessments were evaluated for statistical analyses. The symptomatology observed during the whole course of illness was rediagnosed by DSM-IV criteria.

RESULTS

The paranoid, catatonic, and schizoaffectives subtypes appeared most frequently. There have been no gender differences in age of first psychiatric symptoms (AFS), AFPS, and age of first hospitalization. Kaplan-Meier's survival-analysis carried out for AFPS with sex as the grouping factor revealed that the cumulative prevalence appears to be earlier in females (between 7 and 15 years) than in males (between 10 and 18 years). Of the 44 patients 50 % had a continuing severe course. Patients with onset before 12 years of age were characterized by a chronic/insidious onset, marked premorbid abnormalities, and by a poorer remission. Premorbid features of social withdrawal and reluctance indicated a risk for social disability within the later course.

CONCLUSION

COS, as a rare but severe variant of schizophrenia, frequently develops from premorbid social maladaptation to an insidious onset but is subsequently followed by a transition to a course and outcome not distinguishable from that of adult-onset schizophrenia.

Some remarks on etiological aspects of early-onset schizophrenia

Neurophysiological, neuropsychological, neuroanatomical, and neuroradiological findings in schizophrenic psychoses demonstrate that subcortical (e.g., mesolimbic and diencephalic regions) as well as neocortical structures (e.g., dorsolateral prefrontal cortex, superior temporal and inferior parietal cortices) are involved. Special significance is accorded to the neuroanatomical connection between limbic structures and the dorsolateral prefrontal cortex. Here myelinization begins relatively late in humans, during the second and third decade of life - a particularly vulnerable period for schizophrenic onset. The nature of prepsychotic behavioral abnormalities in patients with early-onset schizophrenia as well as the existence of typical cognitive dysfunctions preceding the manifestation of psychotic symptoms points to the importance of a dynamic imbalance of neocortical-subcortical interactions in the etiology of schizophrenia. Based on the crucial importance of the prefrontal-hippocampal circuitry a stimulus barrier model of schizophrenic psychoses is elaborated, which integrates recent neurobiological findings as well as results of research in modern developmental psychology. One of the implications of this model is the multidimensional treatment of schizophrenic patients.

A lack of cerebral lateralization in schizophrenia is within the normal variation in brain maturation but indicates late, slow maturation

The planum temporale (PT) bias, PT leftward, PT symmetry, and PT rightward reversal and sidedness preference, consistent right-handedness, ambilaterality, and consistent left-handedness are placed on a continuum mirroring the normal variation in rate of brain maturation. Maturational rate declines as we pass from PT leftward bias and consistent right-handedness to PT reversal and consistent left-handedness. Concomitantly, we expect an increased prevalence of males due to their pubertal age being about 2 years later than that of females, and a shift in cognitive profile from higher verbal scores than performance scores on the WAIS to higher performance than verbal scores. Three disorders fulfilling the criteria of late CNS maturation apart from the corresponding cognitive profile were studied: infantile autism (IA), schizophrenia (S), and developmental dyslexia (DD). These disorders have in common deficits in cognition, perception, and somatomotor function. The deficits range from an arrest in brain development (which is evident in infancy superimposed on late maturation in IA) to overall delayed brain and somatic development in S (culminating in postpubertal psychotic episodes and persistent and generalized residual deficits). Finally, reading inability, problems in perception (vision and hearing) and in motor coordination, particularly between the two hemispheres, characterize DD. Enhancing brain maturation and the prevalence of 'normal' cerebral asymmetry--laterality is preferable if we want to reduce the risk of developing the above-mentioned disorders. It is suggested that in the past environmental challenges have favored early maturation, with its abundant neuronal population, arborization and excessive density of synapses and cerebral excitability which has powered evolution through the mechanism of natural selection. Early maturation is obtainable through optimal nutrition, including a satisfactory amount of marine fat (PUFA), before and during pregnancy and later in life.

Components of visual search in childhood-onset schizophrenia and attention-deficit/hyperactivity disorder

This study tested the hypotheses that visual search impairments in schizophrenia are due to a delay in initiation of search or a slow rate of serial search. We determined the specificity of these impairments by comparing children with schizophrenia to children with attention-deficit hyperactivity disorder (ADHD) and age-matched normal children. The hypotheses were tested within the framework of feature integration theory by administering children tasks tapping parallel and serial search. Search rate was estimated from the slope of the search functions, and duration of the initial stages of search from time to make the first saccade on each trial. As expected, manual response times were elevated in both clinical groups. Contrary to expectation, ADHD, but not schizophrenic, children were delayed in initiation of serial search. Finally, both groups showed a clear dissociation between intact parallel search rates and slowed serial search rates.

Working memory in childhood-onset schizophrenia and attention-deficit/hyperactivity disorder

We investigated verbal and spatial working memory in participants with childhood-onset schizophrenia (N=13), attention-deficit/hyperactivity disorder (ADHD; N=31) and age-matched normal children (N=27). The ages of the participants ranged from 9 to 20 years, with an average age of approx. 14 in all groups. Diagnoses were based on structured interviews (Kiddie-Schedule for Affective Disorders and Schizophrenia) with the children and their parents and made using DSM-III-R criteria. Verbal working memory was assessed by the highest number of digits recalled in forward and backward order on the Digit Span subtest of the Wechsler Intelligence Scale. Results showed that normal children recalled more digits than schizophrenic and ADHD children, who did not differ. Spatial working memory was assessed with the Dot Test of Visuospatial Working Memory: The children were presented with a dot on a page for 5 s and asked to mark its location on a blank page immediately after presentation or 30 s later. A distracter task was used during the delay to prevent verbal rehearsal. The average distance between the target dot and the child's mark in the 30-s condition was shorter for normal than for schizophrenic and ADHD children, who did not differ. Thus, both schizophrenic and ADHD children showed deficits in verbal and spatial working memory. These results suggest that in both disorders, the capacity of the sensory buffers may be diminished, and/or the availability and allocation of resources to the central executive may be limited.

Childhood-onset schizophrenia: an open-label study of olanzapine in adolescents

OBJECTIVE

Olanzapine, a potent 5-HT2a/2c, dopamine D1D2D4 antagonist with anticholinergic activity, has a profile of known receptor affinity similar to that of clozapine. This pilot study examined the efficacy of olanzapine for treatment-refractory childhood-onset schizophrenia in eight patients who had received 8-week open-label trials. For comparison, data are included from 15 patients who had received 6-week open-label clozapine trials using identical rating instruments (largely by the same raters) in the same treatment setting.

METHOD

Twenty-three children and adolescents with an onset of DSM-III-R schizophrenia by age 12 for whom at least two different typical neuroleptics had been ineffective participated in the two separate studies. Some of the patients were intolerant of clozapine, although it had been effective (n = 4). Patients receiving olanzapine were evaluated over 8 weeks with the Brief Psychiatric Rating Scale (BPRS), the Scale for the Assessment of Positive Symptoms, the Scale for the Assessment of Negative Symptoms, and the Clinical Global Impressions Scale for Improvement.

RESULTS

For the eight patients who received olanzapine trials, at week 8 there was a 17% improvement in the BPRS total score, a 27% improvement in the Scale for the Assessment of Negative Symptoms, and a 1% improvement in the Scale for the Assessment of Positive Symptoms, relative to "ideal" admission status on typical neuroleptics. In contrast, the magnitude of the effect sizes for each of the clinical ratings was larger at week 6 of the previous clozapine trial than for an 8-week olanzapine trial, relative to admission status on typical neuroleptics. For the four children who had received both clozapine and olanzapine, BPRS total scores were significantly lower at week 6 of clozapine treatment compared with week 6 of olanzapine treatment (p = .03).

CONCLUSION

These data provide preliminary evidence for the efficacy of olanzapine for some children and adolescents with treatment-refractory schizophrenia, but they also suggest the need for a more rigorous double-blind comparison of these two atypical antipsychotics.

"Multidimensionally impaired disorder": is it a variant of very early-onset schizophrenia?

OBJECTIVE

To examine the validity of diagnostic criteria for a subgroup of children with atypical psychosis (n = 19), designated here as "multidimensionally impaired." These children are characterized by poor attention and impulse control, psychotic symptoms, and poor affective control.

METHOD

Children and adolescents (n = 19) meeting our criteria for multidimensionally impaired syndrome with onset of psychotic symptoms at or before age 12 years were identified from a total of 150 in-person screenings for very early-onset schizophrenia between 1990 and 1996. We compared the premorbid adjustment, family history, follow-up status, and laboratory measures for a subgroup of these children with those of (1) a rigorously defined group of 29 children with DSM-III-R schizophrenia and (2) 19 children with attention-deficit hyperactivity disorder.

RESULTS

Patients with multidimensionally impaired syndrome and patients with very early-onset schizophrenia shared a similar pattern of early transient autistic features, postpsychotic cognitive decline, and an elevated risk of schizophrenic-spectrum disorders among their first-degree relatives. This pattern was not seen in the attention-deficit hyperactivity disorder group. In contrast to very early-onset schizophrenia, the multidimensionally impaired group had significantly poorer scores on the Freedom From Distractibility factor on the WISC-R, a less deviant pattern of autonomic reactivity, and no progression to schizophrenia.

CONCLUSIONS

The findings support the distinction of the multidimensionally impaired cases as separate from those with other psychiatric disorders, and there is somewhat greater evidence to suggest that this disorder belongs in the schizophrenia spectrum.