Developmental trajectory and disease progression in schizophrenia: the conundrum, and insights from a 12-year prospective study in the Monaghan 101

Long-Term Effects of Maternal Deprivation on the Volume of Dopaminergic Nuclei and Number of Dopaminergic Neurons in Substantia Nigra and Ventral Tegmental Area in Rats

Early life adversities leave long-lasting structural and functional consequences on the brain, which may persist later in life. Dopamine is a neurotransmitter that is extremely important in mood and motor control. The aim of this study was to investigate the effect of maternal deprivation during the ninth postnatal day on the volume of dopaminergic nuclei and the number of dopaminergic neurons in adolescence and adulthood. Maternally deprived and control Wistar rats were sacrificed on postnatal day 35 or 60, and the dopaminergic neurons were stained in coronal histological sections of ventral midbrain with the tyrosine hydroxylase antibody. The volume of dopaminergic nuclei and the number of dopaminergic neurons in the substantia nigra (SN) and ventral tegmental area (VTA) were analyzed in three representative coordinates. Maternal deprivation caused weight loss on postnatal day 21 (weaning) and corticosterone blood level elevation on postnatal days 35 and 60 in stressed compared to control rats. In maternally deprived animals, the volumes of SN and VTA were increased compared to the controls. This increase was accompanied by an elevation in the number of dopaminergic neurons in both nuclei. Altogether, based on somatic and corticosterone level measurements, maternal deprivation represents a substantial adversity, and the phenotype it causes in adulthood includes increased volume of the dopaminergic nuclei and number of dopaminergic neurons.

Age-Related Reduction in Cortical Thickness in First-Episode Treatment-Naïve Patients with Schizophrenia

Substantial evidence supports the neurodevelopmental hypothesis of schizophrenia. Meanwhile, progressive neurodegenerative processes have also been reported, leading to the hypothesis that neurodegeneration is a characteristic component in the neuropathology of schizophrenia. However, a major challenge for the neurodegenerative hypothesis is that antipsychotic drugs used by patients have profound impact on brain structures. To clarify this potential confounding factor, we measured the cortical thickness across the whole brain using high-resolution T1-weighted magnetic resonance imaging in 145 first-episode and treatment-naïve patients with schizophrenia and 147 healthy controls. The results showed that, in the patient group, the frontal, temporal, parietal, and cingulate gyri displayed a significant age-related reduction of cortical thickness. In the control group, age-related cortical thickness reduction was mostly located in the frontal, temporal, and cingulate gyri, albeit to a lesser extent. Importantly, relative to healthy controls, patients exhibited a significantly smaller age-related cortical thickness in the anterior cingulate, inferior temporal, and insular gyri in the right hemisphere. These results provide evidence supporting the existence of neurodegenerative processes in schizophrenia and suggest that these processes already occur in the early stage of the illness.

The slow death of the concept of schizophrenia and the painful birth of the psychosis spectrum

The concept of schizophrenia only covers the 30% poor outcome fraction of a much broader multidimensional psychotic syndrome, yet paradoxically has become the dominant prism through which everything 'psychotic' is observed, even affective states with mild psychosis labelled 'ultra-high risk' (for schizophrenia). The inability of psychiatry to frame psychosis as multidimensional syndromal variation of largely unpredictable course and outcome - within and between individuals - hampers research and recovery-oriented practice. 'Psychosis' remains firmly associated with 'schizophrenia', as evidenced by a vigorous stream of high-impact but non-replicable attempts to 'reverse-engineer' the hypothesized biological disease entity, using case-control paradigms that cannot distinguish between risk for illness onset and risk for poor outcome. In this paper, the main issues surrounding the concept of schizophrenia are described. We tentatively conclude that with the advent of broad spectrum phenotypes covering autism and addiction in DSM5, the prospect for introducing a psychosis spectrum disorder - and modernizing psychiatry - appears to be within reach.

Decreased Resting-State Interhemispheric Functional Connectivity Correlated with Neurocognitive Deficits in Drug-Naive First-Episode Adolescent-Onset Schizophrenia

BACKGROUND

Given that adolescence is a critical epoch in the onset of schizophrenia, studying aberrant brain changes in adolescent-onset schizophrenia, particularly in patients with drug-naive first-episode schizophrenia, is important to understand the biological mechanism of this disorder. Previous resting-state functional magnetic resonance imaging studies have shown abnormal functional connectivity in separate hemispheres in patients with adult-onset schizophrenia. Our aim to study adolescent-onset schizophrenia can provide clues for the early aetiology of schizophrenia.

METHOD

A total of 48 drug-naïve, first-episode, adolescent-onset schizophrenia outpatients and 31 healthy controls underwent resting-state functional magnetic resonance imaging scans. Data were subjected to voxel-mirrored homotopic connectivity and support vector machine analyses.

RESULTS

Compared with the healthy controls, the adolescent-onset schizophrenia group showed significantly lower voxel-mirrored homotopic connectivity values in different brain regions, including the fusiform gyrus, superior temporal gyrus/insula, precentral gyrus, and precuneus. Decreased voxel-mirrored homotopic connectivity values in the superior temporal gyrus/insula were significantly correlated with Trail-Making Test: Part A performance (r = -0.437, P = .002). A combination of the voxel-mirrored homotopic connectivity values in the precentral gyrus and precuneus may be used to discriminate patients with adolescent-onset schizophrenia from controls with satisfactory classification results, which showed sensitivity of 100%, specificity of 87.09%, and accuracy of 94.93%.

CONCLUSION

Our findings highlight resting-state interhemispheric FC abnormalities within the sensorimotor network of patients with adolescent-onset schizophrenia and confirm the relationship between adolescent-onset schizophrenia and adult-onset schizophrenia. These findings suggest that reduced interhemispheric connectivity within the sensorimotor network has a pivotal role in the pathogenesis of schizophrenia.

Management of schizophrenia in late life with antipsychotic medications: a qualitative review

Although patients with schizophrenia are reported to have excess mortality compared with the general population, many affected patients will nonetheless survive and continue to have the disorder in later life. Consequently, geriatric schizophrenia will be a significant public health concern in the years to come, and evidence-based treatment of schizophrenia in older patients is becoming an urgent issue. However, there has been a paucity of comparative data to guide selection of antipsychotics for schizophrenia in late life. The primary aim of this review was to synthesize the available evidence on management of late-life schizophrenia with antipsychotic medications; a secondary aim was to evaluate treatment resistance in this population. Accordingly, PubMed and EMBASE were searched using the keywords 'antipsychotics', 'age' and 'schizophrenia' to identify psychopharmacological studies of antipsychotics in late-life schizophrenia (last search 30 April 2011). The literature search identified 23 prospective studies of use of antipsychotics for schizophrenia in older patients (generally age ≥65 years), including eight double-blind trials. The sample size was smaller than 40 patients for 52% of the studies. Two of the double-blind studies were post hoc analyses and one was a placebo-controlled trial. In the largest double-blind study, olanzapine (n = 88, median dose 10 mg/day) and risperidone (n = 87, median dose 2 mg/day) were compared in patients not resistant to these therapies, with similar effects. There have also been several open-label trials of these two agents that have shown efficacy and tolerability in non-resistant patients. Evidence on other antipsychotics has been scarce and less robust. The gold standard for treatment-resistant schizophrenia is clozapine. However, almost all of the studies of clozapine to date have effectively excluded older patients with schizophrenia. Only one small study has evaluated clozapine (n = 24, mean dose 300 mg/day) in comparison with chlorpromazine (n = 18, mean dose 600 mg/day) in a difficult-to-treat older population; the investigators reported that both treatments were similarly efficacious. Furthermore, there has been little compelling evidence in favour of or against augmentation of antipsychotics with other psychotropic medications in the older age group. Treatment of non-resistant, late-life schizophrenia with olanzapine and risperidone appears to be supported by the available evidence. However, data on geriatric patients with schizophrenia are generally scarce, particularly for treatment-resistant subpopulations, underscoring the need for more research in this important area.

Predictors of 10-year outcome of first-episode psychosis

BACKGROUND

Predictors of outcome for psychosis are poorly understood. Duration of untreated psychosis (DUP) appears to predict short-term outcome although its medium- to long-term role remains unclear. Neurodevelopmental indices such as pre-morbid function and/or neurological soft signs may predict longer-term outcome. We aimed to assess the impact of a range of clinical and demographic variables on long-term outcome of a geographically defined, epidemiological first-episode psychosis cohort.

METHOD

A 10-year follow-up was undertaken of a consecutively presenting sample of 109 cases of first-episode psychosis aged 16-50 years. Baseline assessments included positive, negative and depression symptoms, DUP, neurological soft signs and pre-morbid functioning. Multi-dimensional outcomes were assessed blind to baseline data.

RESULTS

All participants were traced at a mean of 10.5 years post-index admission: 11 had died, 10 from non-natural causes. Of the surviving cases, 70% were comprehensively re-assessed by interview. Summary data on the remainder were collected from their family practitioner and chart review. Poor 10-year outcomes were predicted independently by poor pre-morbid functioning, baseline negative symptoms and longer DUP. The same measures, plus neurological soft signs, appeared to predict outcomes in a DSM-IV schizophrenia/schizo-affective subgroup.

CONCLUSIONS

Poor pre-morbid functioning, baseline symptoms, DUP and neurological soft signs at onset independently predict poor long-term outcome in first-episode psychosis.

Longitudinal brain changes in early-onset psychosis

Progressive losses of cortical gray matter volumes and increases in ventricular volumes have been reported in patients with childhood-onset schizophrenia (COS) during adolescence. Longitudinal studies suggest that the rate of cortical loss seen in COS during adolescence plateaus during early adulthood. Patients with first-episode adolescent-onset schizophrenia show less marked progressive changes, although the number of studies in this population is small. Some studies show that, although less exaggerated, progressive changes are also present in nonschizophrenia early-onset psychosis. The greater loss of brain tissue seen in COS, even some years after the first episode, as compared to adolescent- or adult-onset schizophrenia may be due to variables such as sample bias (more severe, treatment refractory sample of childhood-onset patients studied), a process uniquely related to adolescent development in COS, differential brain effects of drug treatment in this population, clinical outcome, or interactions among these variables. Findings from both cross-sectional studies of first-episode patients and longitudinal studies in COS and adolescent onset support the concept of early-onset schizophrenia as a progressive neurodevelopmental disorder with both early and late developmental abnormalities. Future studies should look for correlates at a cellular level and for pathophysiological explanations of volume changes in these populations. The association of risk genes involved in circuitries associated with schizophrenia and their relationship to developmental trajectories is another promising area of future research.

Progressive and interrelated functional and structural evidence of post-onset brain reduction in schizophrenia

CONTEXT

Progressive brain abnormalities in schizophrenia remain controversial. Evidence of interrelated progressive functional impairment would buttress the case for structural progression. Mismatch negativity (MMN) is reduced in chronic but not first-hospitalized schizophrenia and may index progressive structural changes.

OBJECTIVE

To determine whether MMN shows associations with underlying auditory cortex gray matter at first hospitalization and progressive reduction longitudinally.

DESIGN

Cross-sectional (first hospitalization) and longitudinal (1.5-year follow-up).

SETTING

A private psychiatric hospital.

PARTICIPANTS

Protocol entrance: MMN and magnetic resonance imaging at first hospitalization in 20 subjects with schizophrenia, 21 subjects with bipolar disorder with psychosis, and 32 control subjects. Longitudinal electrophysiologic testing: MMN in 16 subjects with schizophrenia, 17 subjects with bipolar disorder, and 20 control subjects. Longitudinal electrophysiologic testing and magnetic resonance imaging: MMN and magnetic resonance imaging in 11 subjects with schizophrenia, 13 subjects with bipolar disorder, and 13 control subjects. At each time point, reported samples were group matched for age, handedness, and parental socioeconomic status.

INTERVENTIONS

Electrophysiologic testing and high-resolution structural magnetic resonance imaging.

MAIN OUTCOME MEASURES

Mismatch negativity amplitude and Heschl gyrus and planum temporale gray matter volumes.

RESULTS

Initially, groups did not differ in MMN amplitude. Subjects with schizophrenia showed associations between MMN and Heschl gyrus (r=-0.52; P=.02) not present in the other groups. At longitudinal MMN testing, schizophrenia showed MMN reduction (P=.004). Only schizophrenia evinced longitudinal left hemisphere Heschl gyrus reduction (P=.003), highly correlated with MMN reduction (r=0.6; P=.04).

CONCLUSIONS

At first hospitalization for schizophrenia, MMN indexed left hemisphere Heschl gyrus gray matter volume, consistent with variable progression of pre-hospitalization cortical reduction. Longitudinally, the interrelated progressive reduction of functional and structural measures suggests progressive pathologic processes early in schizophrenia. An active process of progressive cortical reduction presents a potential therapeutic target. Mismatch negativity may be a simple, sensitive, and inexpensive index not only of this progressive pathologic process but also of successful intervention.

Acute and transient psychotic disorders: precursors, epidemiology, course and outcome

BACKGROUND

ICD-10 has introduced the diagnostic group acute and transient psychotic disorders (ATPDs; F23).

AIMS

To validate the nosological distinctiveness of ICD-10 ATPDs by following up an inception cohort with first-episode psychosis.

METHOD

All patients with first-episode psychosis identified in Nottingham between 1992 and 1994 and diagnosed using ICD-10 criteria were reassessed 3 years later. ATPD outcomes were compared with schizophrenia and affective psychosis. Multivariate analyses were conducted to determine whether acute onset and early remission predicted favourable 3-year outcome in first-episode psychosis.

RESULTS

Of 168 cases of first-episode psychosis, 32 (19%) received an intake diagnosis of ATPD. The diagnosis of ATPD was stable in women over 3 years, but not in men. Outcomes in ATPD were better than in schizophrenia and similar to affective psychosis. In non-affective psychoses, favourable outcomes were a function of gender and premorbid functioning rather than acute onset and early remission.

CONCLUSIONS

The ICD-10 criteria for ATPDs identify a diagnostically unstable group of disorders. Acute onset and early remission do not independently predict favourable outcome over 3 years in first-episode psychosis.

Longitudinal assessment of psychopathological domains over late-stage schizophrenia in relation to duration of initially untreated psychosis: 3-year prospective study in a long-term inpatient population

There remains uncertainty regarding any progressive nature of psychopathology and cognitive dysfunction in late-stage schizophrenia, and whether duration of initially untreated psychosis (DUP) might be associated with such 'progression'. This study examines longitudinally, over 3 years, the psychopathology and neuropsychology in 82 inpatients with DSM-IV schizophrenia, many of whom were admitted in the pre-neuroleptic era. Increase in executive dysfunction exceeded that in general cognitive impairment. Positive but not negative symptom severity decreased modestly; the primary predictor of negative symptom severity was DUP. On index assessment, psychopathology evidenced a three-factor structure; at follow-up, psychomotor poverty evidenced greater prominence and cohesion, and was on both occasions predicted primarily by DUP, while reality distortion was altered and disorganisation disassembled into alternative elements. It would appear that as years of chronic, refractory illness accrue, psychomotor poverty becomes more sharply delineated and dominant within the overall structure of psychopathology, and its prominence is predicted enduringly by DUP.

Differential regulation of hippocampal BDNF mRNA by typical and atypical antipsychotic administration

Apart from their differential propensities to block dopamine D2 and serotonin 5-HT2 receptors, the molecular mechanisms underlying the clinical efficacy of typical and atypical antipsychotics in schizophrenia are largely unknown. Given recent interest in the effects of antipsychotics on neurotrophic and other growth related factors, the effects of antipsychotics on brain-derived neurotrophic factor (BDNF), a neurotrophin crucial to the structural integrity of adult neurons, were investigated in male Wistar rats. Chronic (19 day) but not acute (45 min) antipsychotic administration significantly altered levels of hippocampal BDNF mRNA. In addition, whereas chronic treatment with the strong D2 receptor-blocker haloperidol significantly downregulated hippocampal BDNF mRNA, the selective 5-HT2 receptor-blocker ritanserin significantly upregulated CA1 hippocampal BDNF mRNA in comparison to controls. Since high doses of risperidone and clozapine produce potent inhibition of both 5-HT2 and D2 receptors, while lower doses produce significantly greater 5-HT2 vs. D2 receptor blockade, a dose-response study was employed to determine whether low doses of these atypical antipsychotics would also upregulate hippocampal BDNF mRNA in the absence of significant D2 receptor blockade. Whereas chronic haloperidol and high-dose risperidone significantly downregulated hippocampal BDNF mRNA, intermediate and lower doses of risperidone and clozapine were, unlike ritanserin, without effect when compared to controls. Thus, although the long-term downregulation of hippocampal BDNF mRNA may underlie the different clinical profiles of certain antipsychotics, this effect seems to be associated with antipsychotic doses that not only cause significant D2 receptor inhibition, but are usually associated with side effects rather than therapeutic efficacies.

Rationale for the study of early intervention

Consistent but relatively weak evidence exists that treating patients with schizophrenia early in the course of their illness can decrease long-term morbidity. Relatedly, it is possible that treating individuals even earlier might produce better results. The findings presented set the stage for early and even earlier formal intervention studies, where the potential benefits are thought to outweigh the potential risks.

Relationship of the factor structure of psychopathology in schizophrenia to the timing of initial intervention with antipsychotics

Timing of intervention with antipsychotic medication may influence long-term outcome in schizophrenia in a manner that is poorly understood. This study evaluated psychopathology, its factor structure, and cognitive dysfunction in older patients with chronic schizophrenia in relation to the intervals from onset of psychosis to initiation of treatment with antipsychotics, and from initiation of antipsychotic treatment to current assessments. The subjects were 129 patients with schizophrenia, many of whom became ill in the preneuroleptic era. Their current psychopathology was assessed using the Positive and Negative Syndrome Scale, and its factor structure examined using principal component analysis. Current general and executive cognitive function was evaluated using the Mini-Mental State Examination and the Executive Interview, respectively. Using multiple regression modelling, increasing duration of initially unmedicated psychosis, but not the much longer duration of subsequently treated illness, was the primary predictor of psychomotor poverty (negative symptoms) but not of reality distortion or disorganisation over the three domains of psychopathology resolved; duration of initially unmedicated psychosis marginally predicted the severity of general, but not of executive, cognitive dysfunction. Delayed intervention with antipsychotics appears associated with poorer long-term course in terms of increased severity of psychopathology in the psychomotor poverty domain.

A prospective longitudinal 10-year study of schizophrenia's three major factors and depression

This study investigated the nature, independence, and stability of schizophrenia's syndrome factors and depression at 2, 4.5, 7.5 and 10 years post-index hospitalization. At the four follow-ups, 71 patients (48 with schizophrenia and 23 with schizoaffective disorder) were assessed for symptoms hypothesized to constitute the reality distortion, disorganized, and negative factors of schizophrenia. At the last three follow-ups, the patients were also assessed for symptoms of depression. Factor analyses of schizophrenia symptoms revealed more than three syndrome factors at each follow-up. Longitudinally, reality distortion was a stable and relatively independent factor. The negative syndrome was independent but was bifurcated into two dimensions, interpreted as social/emotional withdrawal and diminished movement/expressiveness. Although signs of disorganization were not unified or independent early in schizophrenia's course, speech/thought disorder, disorganized affect, and poverty of speech content coalesced to form a disorganization factor by the 7.5-year follow-up. When depressive symptoms were added to the analyses, depression constituted an independent and stable dimension of schizophrenia over time. Each schizophrenia factor demonstrated a unique longitudinal course. Courses included stable symptom consistency (reality distortion), evolving symptom convergence (disorganization), and recurrent bifurcation and symptom instability (the negative syndrome).

Early cerebro-craniofacial dysmorphogenesis in schizophrenia: a lifetime trajectory model from neurodevelopmental basis to 'neuroprogressive' process

Understanding the temporal origin(s) of schizophrenia, through specifying the earliest identifiable pathology, might indicate when to look for etiological factor(s), what their nature might be, and how course of illness might evolve from these origins. From this premise, earlier formulations are elaborated to offer a rigorously data-driven model that roots schizophrenia in cerebro-craniofacial dysmorphogenesis, particularly along the mid-line but involving other structures, over weeks 9/10 through 14/15 of gestation. However, a brain that has been compromised very early in fetal life is still subject to the normal endogenous programme of developmental, maturational and involutional processes on which a variety of exogenous biological insults and psychosocial stressors can impact adversely over later pregnancy, through infancy and childhood, to maturation and into old age, to sculpt brain structure and function; it should be emphasised that the effects of such endogenous programmes and exogenous insults on such an already developmentally-compromised brain may be different from their effects on a brain whose early fetal origins were unremarkable. From these early origins, a lifetime trajectory model for schizophrenia from developmental basis to 'neuroprogressive' process is constructed. Thereafter, consideration is given to what the model can explain, including cerebral asymmetry and homogeneity, what it cannot explain, what empirical findings would challenge or disprove the model, what cellular and molecular mechanisms might underpin the model, and what are its implications.

Is schizophrenia a neurodegenerative disorder? A clinical and neurobiological perspective

The history of psychiatric research is filled with widely accepted etiologic and pathophysiologic theories that eventually were proven wrong. The prevailing pathophysiologic theories of schizophrenia have emphasized the role of abnormal neurodevelopment in determining the onset and course of the illness. Relatively little attention has been paid to the role of neurodegenerative processes despite the clinical course of the illness and the fact that most patients experience varying degrees of behavioral and cognitive deterioration. This is partially due to the absence of clear histologic evidence of neurodegeneration, but may also be due to the narrow traditional conception of neurodegeneration that is generally employed. This article suggests that the rejection of a role for neurodegeneration in the pathophysiology of schizophrenia is unproven and may be premature. A wholly neurodevelopmental perspective of the illness imbues the illness with a pessimistic inevitability and therapeutic nihilism that may be unwarranted. This article reviews selectively a diverse body of evidence that is consistent with the hypothesis that schizophrenia involves a limited neurodegenerative process reflected by the psychotic symptoms and that is most active in the early stages of the illness. The evidence for this hypothesis comes from studies of premorbid status, illness course, symptomatology and treatment effects as well as neuroimaging and postmortem findings. Recent results from the latter interpreted in the context of molecular neurobiology suggest new pathophysiologic models.

CSF N-CAM in neuroleptic-naïve first-episode patients with schizophrenia

An increased concentration of neural cell adhesion molecule (N-CAM) 105-115 kDa has been reported in patients with schizophrenia in both CSF and in post-mortem brain samples. To determine whether increased N-CAM is integral to the disease process or, alternatively, results from early treatment, CSF N-CAM was measured in a blind study of first episode (FE) patients, who were either neuroleptic-naïve (NN) or neuroleptic-treated (NT, < 100 mg Haldol equivalents), multi-episode (ME) patients, and controls. Overall, the FE patients displayed lower N-CAM concentrations as compared to controls (p = 0.043). This decrease in N-CAM in FE patients was seen only in the FE-NT group as compared to both controls (p = 0.0006). The FE-NT group also showed a lower CSF N-CAM compared to that in the FE-NN (p = 0.025) group. No difference in CSF N-CAM between the FE-NN and control group was found. ME patients showed an increased N-CAM as compared with FE patients (p = 0.018), but not as compared to controls (p = 0.93). Neuroleptic-naïve first-episode patients do not display a phenotypic increase in N-CAM. Thus, N-CAM is altered in first-episode patients following acute neuroleptic treatment and withdrawal, as compared to neuroleptic-naïve first-episode patients.

Mini-Mental State Examination (MMSE) performance of partially remitted community-dwelling patients with schizophrenia

Patients with schizophrenia perform worse than healthy controls on many neuro-psychological tests. However, previous studies of neuro-cognitive function have mostly been carried out on acutely ill or institutionalized patients. The objective of this study was to generate norms for performance of partially remitted community-dwelling patients with schizophrenia on the Mini-Mental State Examination (MMSE). Partially remitted outpatients attending a depot antipsychotic clinic or a clozapine clinic (n = 272) were tested using the MMSE. Demographic and clinical characteristics associated with MMSE performance, as well as the performance of specific items, were examined. MMSE score was significantly associated with educational status and race. Patients in our sample performed approximately 2-3 points below the population norms at all ages, but the mean score for the group was not in the impaired range. There was no apparent widening of this gap with advancing age. Patients who did poorly most frequently had difficulty with memory, attention and construction tasks. The MMSE is easy to administer to outpatients with schizophrenia and most patients score in the un-impaired range. The MMSE may be used to identify a subgroup of patients who score in the impaired range, for further investigations.

Course of psychopathology, cognition and neurobiological abnormality in schizophrenia: developmental origins and amelioration by antipsychotics?

It is argued that schizophrenia has origins in events occurring during the first or early second trimester that are reflected in minor physical anomalies and which may at least in part predispose to later obstetric complications. This neurodevelopmental basis underlies certain neuromotor and psychosocial abnormalities of infancy and childhood, which are the early manifestations of what will be reconceptualised later as negative symptoms and (particularly frontal) cognitive dysfunction, but gives rise to positive symptoms only on the maturation of other systems necessary for their expression. This later emergence of psychosis may reflect an active morbid process that is associated with increased accrual of negative symptoms and of general (but not frontal) cognitive impairment that may be ameliorated by effective antipsychotic treatment. The psychological or biological basis of this heuristic process is poorly understood. Contemporary re-appraisal of any impact of antipsychotics on the long-term course of schizophrenia must take into account what is known of the origins of the disease process with which such drugs might interact. Much recent work continues to indicate that very early events, during the embryonic/fetal period, are important in, if not fundamental to, the genesis of schizophrenia; i.e. that there is a neurodevelopmental basis to the disorder. The present article seeks to establish a time-line relating early intrauterine adversity and dysmorphogenesis, through the onset of psychosis, to the chronic phase of the illness over adulthood; from this time-line, a schema is elaborated for a beneficial impact of antipsychotics on the course of psychopathology, cognition and, less clearly, neurobiological abnormality.

Neurodevelopmental and neuroprogressive processes in schizophrenia. Antithetical or complementary, over a lifetime trajectory of disease?

The neurodevelopmental model of schizophrenia maintains ascendancy among current etiopathologic perspectives on schizophrenia. However, inconsistencies across studies and the absence thus far of pathognomic brain changes suggest the need for complex conceptualization of neurodevelopmental arrest, including some reconciliation with the competing neurodegenerative model of schizophrenia. This article critically reviews the preponderance of evidence for each model and provides an account of how these may interact or synergize to produce the characteristic clinical expression of schizophrenia.

The new antipsychotics, and their potential for early intervention in schizophrenia

Over almost four decades, few fundamentally different antipsychotic drugs evolved to challenge classical neuroleptics as the mainstay of the pharmacotherapy of schizophrenia. However, the recent re-emergence of clozapine, together with the emergence of risperidone, portends an increasing number of new antipsychotics which are now either traversing the stages of regulatory approval or else well-advanced in clinical development. This article first evaluates the significance of clozapine and risperidone; it then reviews some of the new antipsychotics and how they might be classified vis-a-vis potential advantages for patients, outlines putative mechanisms and new therapeutic targets, and considers whether such agents may act on any disease process inherent to schizophrenia. One fundamental issue is the extent to which the new antipsychotics might shift materially the risk benefit balance towards intervention, not just at the earliest possible stage following the onset of psychosis but at a yet earlier, 'prodromal' phase of the disorder where there is a considerably greater likelihood of 'treating' behavioural disturbances that prove not to be the harbingers of psychotic illness.

Functional brain imaging and aging in schizophrenia

Patients with schizophrenia, even early in the course of illness, show some similarities in their brain-imaging findings to those in older normal controls: for example, ventricular enlargement and diminished functional activity in the frontal cortex. These findings suggest a possible similarity between the normal aging process and schizophrenia, or the possible existence in some schizophrenic patients of progressive processes that prematurely affect the brain in ways analogous to normal aging. In contrast to other brain regions, the basal ganglia in schizophrenia may show an atypical pattern of volumetric and metabolic change over time, possibly because of the effects of neuroleptic treatment. However, age and illness duration are highly correlated in our samples. Interpretation of imaging results is limited by the lack of studies in an adequate number of either first-break or older schizophrenic patients and the dearth of studies with longitudinal designs.

Executive (frontal) dysfunction and negative symptoms in schizophrenia: apparent gender differences in 'static' v. 'progressive' profiles

BACKGROUND

While executive (frontal lobe) dysfunction appears to be a core feature of schizophrenia, its relationship to psychopathology, age and duration of illness has yet to be explored systematically between the genders.

METHOD

Executive dysfunction, positive and negative symptoms were evaluated in 27 male and 21 female in-patients who were unusually well-matched on numerous demographic and clinical measures.

RESULTS

Measures of executive dyscontrol and negative symptoms were highly associated in both genders. However, while both executive dyscontrol and negative symptoms increased prominently with age/ duration of illness among women, no such relationship was evident among men.

CONCLUSIONS

The similarly prominent levels of current executive dyscontrol and negative symptoms in male and female patients appear to have emerged via processes that differ fundamentally between the genders; among males these deficits appear to emerge and become 'locked in' earlier in the course of illness and to show little subsequent increase, while among females these same deficits appear to be less evident early in the course but to increase in prominence thereafter.