Cognitive dysfunction in chronic schizophrenia followed prospectively over 10 years and its longitudinal relationship to the emergence of tardive dyskinesia

The association between alterations in motor and cognitive dimensions of schizophrenia-spectrum disorders: A systematic review

Motor and cognitive alterations in schizophrenia-spectrum disorders (SSD) share common neural underpinnings, highlighting the necessity for a thorough exploration of the connections between these areas. This relationship is crucial, as it holds potential significance in unraveling the underlying mechanisms of SSD pathophysiology, ultimately leading to advancements in clinical staging and treatment strategies. The purpose of this review was to characterize the relationship between different hyper and hypokinetic domains of motor alterations and cognition in SSD. We systematically searched the literature (PROSPERO protocol CRD42019145964) and selected 66 original scientific contributions for review, published between 1987 and 2022. A narrative synthesis of the results was conducted. Hyper and hypokinetic motor alterations showed weak to moderate negative correlations with cognitive function across different SSD stages, including before antipsychotic treatment. The literature to date shows a diverse set of methodologies and composite cognitive scores hampering a strong conclusion about which specific cognitive domains were more linked to each group of motor alterations. However, executive functions seemed the domain more consistently associated with parkinsonism with the results regarding dyskinesia being less clear. Akathisia and catatonia were scarcely discussed in the reviewed literature. The present review reinforces the intimate relationship between specific motor alterations and cognition. Identified gaps in the literature challenge the formulation of definitive conclusions. Nevertheless, a discussion of putative underlying mechanisms is included, prompting guidance for future research endeavors.

Efficacy and safety of Transcranial Direct Current Stimulation (tDCS) on cognitive function in chronic schizophrenia with Tardive Dyskinesia (TD): a randomized, double-blind, sham-controlled, clinical trial

OBJECTIVE

Previous studies have shown that transcranial direct current stimulation(tDCS) led to an improvement of cognitive function in patients with schizophrenia, but rare study has explored the effect of tDCS on long-term hospitalized chronic schizophrenia with tardive dyskinesia (TD). The present research explored if cognitive function in patients with long-term hospitalized chronic schizophrenia with TD could be improved through tDCS.

METHODS

This study is a randomized, double-blind, sham-controlled clinical trial. Of the 52 patients, 14 dropped out, and 38 completed the experiment. Thirty-eight patients on stable treatment regimens were randomly assigned to receive active tDCS(n = 21) or sham stimulation(n = 17) on weekdays of the first, third, and fifth weeks of treatment. Patients performed the Pattern Recognition Memory (PRM) and the Intra/Extradimensional Set Shift (IED) from the Cambridge Neuropsychological Test Automated Battery (CANTAB) at baseline and the end of week 3, week 5. Clinical symptoms were also measured at the baseline and the fifth week using the Scale for the Assessment of Negative Symptoms (SANS) and the Positive and Negative Syndrome Scale (PANSS). Side effects of tDCS were assessed with an experimenter-administered open-ended questionnaire during the whole experiment.

RESULTS

There were no significant differences in PRM and IED performance metrics, SANS total score and PANSS total score between active and sham tDCS groups at the end of week 5 (p > 0.05). Furthermore, there was a significant difference in the adverse effects of the tingling sensation between the two groups (p < 0.05), but there was no significant difference in other side effects (p > 0.05).

CONCLUSION

According to these findings, no evidence supports using anodal stimulation over the left dorsolateral prefrontal cortex to improve cognitive function in patients with long-term hospitalized chronic schizophrenia with TD.

Sex difference in association between tardive dyskinesia and cognitive deficits in patients with chronic schizophrenia

BACKGROUND

Tardive dyskinesia (TD), a side effect due to long-term use of antipsychotic medication, is associated with cognitive impairment. Several studies have found sex differences in cognitive impairment in schizophrenia patients, while whether there are sex differences in cognitive performance in schizophrenia patients with TD has not been reported.

METHODS

A total of 496 schizophrenia inpatients and 362 healthy controls were recruited for this study. We used the Positive and Negative Syndrome Scale (PANSS) to assess patients' psychopathological symptoms and the Abnormal Involuntary Movement Scale (AIMS) to assess the severity of TD. Cognitive function was measured in 313 of these inpatients and 310 of healthy controls using the Repeatable Battery for Assessment of Neuropsychological Status (RBANS).

RESULTS

Patients with schizophrenia performed worse in all cognitive domains than healthy controls(all p < 0.001). Compared to patients without TD, patients with TD had higher PANSS total, PANSS negative symptom subscale and AIMS scores (all p < 0.001), while RBANS total, visuospatial/constructional and attention subscale scores were significantly lower (all p < 0.05). In addition, the visuospatial/constructional and attention indices remained significantly lower in male patients with TD than those without TD (both p < 0.05), but these results were not observed in female patients. Moreover, visuospatial/constructional and attention indices were negatively correlated with total AIMS scores only in male patients (both p < 0.05).

CONCLUSION

Our results suggest that there may be sex differences in cognitive impairment in schizophrenia patients with comorbid TD, indicating that female gender may have a protective effect on cognitive impairment in schizophrenia patients caused by TD.

PPARγ receptors are involved in the effects of cannabidiol on orofacial dyskinesia and cognitive dysfunction induced by typical antipsychotic in mice

Tardive dyskinesia (TD) is a movement disorder that appears after chronic use of drugs that block dopaminergic receptors such as antipsychotics. Besides the motor symptoms, patients with TD also present cognitive deficits. Neuroinflammatory mechanisms could be involved in the development of these symptoms. A previous study showed that cannabidiol (CBD), the major non-psychotomimetic compound of Cannabis sativa plant, prevents orofacial dyskinesia induced by typical antipsychotics by activating peroxisome proliferator-activated receptors gamma (PPARγ). Here, we investigated if CBD would also reverse haloperidol-induced orofacial dyskinesia and associated cognitive deficits. We also verified if these effects depend on PPARγ receptor activation. Daily treatment with haloperidol (3 mg/kg, 21 days) increased the frequency of vacuous chewing movements (VCM) and decreased the discrimination index in the novel object recognition test in male Swiss mice. CBD (60 mg/kg/daily) administered in the last 7 days of haloperidol treatment attenuated both behavioral effects. Furthermore, haloperidol increased IL-1β and TNF-α levels in the striatum and hippocampus while CBD reverted these effects. The striatal and hippocampal levels of proinflammatory cytokines correlated with VCM frequency and discrimination index, respectively. Pretreatment with the PPARγ antagonist GW9662 (2 mg/kg/daily) blocked the behavioral effects of CBD. In conclusion, these results indicated that CBD could attenuate haloperidol-induced orofacial dyskinesia and improve non-motor symptoms associated with TD by activating PPARγ receptors.

A systematic review of the prognostic value of motor abnormalities on clinical outcome in psychosis

Schizophrenia spectrum disorders have heterogeneous outcomes and currently no marker predicts the course of illness. Motor abnormalities (MAs) are inherent to psychosis, the risk of psychosis, symptom severity, and brain alterations. However, the prognostic value of MAs is still unresolved. Here, we provide a systematic review of longitudinal studies on the prognostic role of MAs spanning individuals at clinical high risk for psychosis (CHR), patients with first-episode psychosis (FEP), and chronic schizophrenia. We included 68 studies for a total of 23,630 subjects that assessed neurological soft signs (NSS), hypo- or hyperkinetic movement disorders and/or catatonia as a prognostic factor on clinical and functional outcomes. We found increased levels of MAs, in particular NSS, parkinsonism, and dyskinesia, were related to deteriorating symptomatic and poor functional outcome over time. Collectively, the findings emphasize the clinical, prognostic and scientific relevance of MA assessment and detection in individuals with or at risk of psychosis. In the future, instrumental measures of MA are expected to further augment detection, early intervention and treatment strategies in psychosis.

Effects of NBI-98782, a selective vesicular monoamine transporter 2 (VMAT2) inhibitor, on neurotransmitter efflux and phencyclidine-induced locomotor activity: Relevance to tardive dyskinesia and antipsychotic action

Valbenazine, a vesicular monoamine transporter 2 (VMAT2, SLC18A2) inhibitor, is a newly approved treatment for tardive dyskinesia. VMAT2 is present in the membrane of secretory vesicles and transports dopamine (DA), norepinephrine (NE), serotonin (5-HT), histamine, glutamate (Glu), and GABA into vesicles for presynaptic release. We utilized microdialysis in awake, freely moving mice to determine the effect of NBI-98782, the active metabolite of valbenazine, alone, or in combination with several antipsychotic drugs (APDs), to influence neurotransmitter efflux in the medial prefrontal cortex (mPFC), dorsal striatum (dSTR), hippocampus and nucleus accumbens (NAC); we also compared it with tetrabenazine, the prototypical VMAT2 inhibitor. Acute NBI-98782 and tetrabenazine decreased mPFC, dSTR, hippocampus, and NAC DA, 5-HT, and NE efflux, while increasing that of DOPAC, HVA, and 5-HIAA. Sub-chronic NBI-98782 (7 days) decreased baseline DA and 5-HT efflux in both mPFC and dSTR. NBI-98782 elicited similar effects on neurotransmitter efflux in sub-chronic NBI-98782-treated mice but also enhanced ACh and GABA; the decrease in DA efflux in mPFC and dSTR was not significant in the sc-treated animals. NBI-98782 suppressed clozapine-, olanzapine- and risperidone-induced DA efflux in both mPFC and dSTR, and ACh efflux in mPFC. NBI-98782 suppressed the haloperidol-induced DA efflux in dSTR, with minimal effect on GABA efflux. NBI-98782 attenuated PCP-induced DA, 5-HT, NE and Glu efflux, and AMPH-induced DA and NE efflux, in both mPFC and dSTR, as well as PCP- and AMPH-induced hyperlocomotion, suggesting possible beneficial antipsychotic effects.

Community transition at younger ages contributes to good cognitive function outcomes in long-term hospitalized patients with schizophrenia spectrum disorder: A 15-year follow-up study with group-based trajectory modeling

AIM

Cognitive dysfunction is a core symptom of schizophrenia spectrum disorder, but the reported long-term cognitive outcomes are heterogeneous. This study aimed to elucidate the long-term trajectories of patients with schizophrenia spectrum disorder who transitioned to community dwelling with integrated care, and to identify predictors of successful community reintegration.

METHODS

After the closure of a psychiatric hospital, 78 patients with schizophrenia spectrum disorder (mean age: 54.6 years) were transferred to the community. We assessed patients' cognitive function over 15 years with the Mini-Mental State Examination (MMSE) and analyzed the scores every 3 years. Forty-four patients completed all assessments.

RESULTS

The mean MMSE score at discharge was 25.8, which changed to 26.8 after 3 years and 25.3 after 6 years. After 12 and 15 years, it had decreased significantly to 23.3 and 23.0, respectively. Group-based trajectory modeling identified two groups of patients: a 'poor-outcome' group (63.4%), showing a decline in scores after maintaining post-discharge levels for several years, and a 'good-outcome' group (36.6%), maintaining post-discharge scores after showing improved scores.

CONCLUSION

Considering the significant difference in age between the aforementioned groups (P = 0.040), we suggest that community transitions at younger ages contribute to better cognitive function and adaptation to community life. Even middle-aged and elderly patients with chronic schizophrenia spectrum disorder showed improved or maintained cognitive function at least 3 years after discharge, and the good-outcome group maintained cognitive function over 15 years. Improvements were dominated primarily by age at discharge, with cognitive function being maintained longer in patients in the good-outcome group.

Motor abnormalities and cognitive impairment in first-episode psychosis patients, their unaffected siblings and healthy controls

Motor abnormalities (MAs) may be already evidenced long before the beginning of illness and are highly prevalent in psychosis. However, the extent to which the whole range of MAs are related to cognitive impairment in psychosis remains understudied. This study aimed to examine comparatively the relationships between the whole range of motor abnormalities and cognitive impairments in the first-episode of psychosis (FEP), their unaffected siblings and healthy control subjects. Fifty FEP patients, 21 of their healthy siblings and 24 age- and sex matched healthy controls were included. Motor assessment included catatonic, extrapyramidal and neurological soft signs (NSS) by means of standardized instruments. An exhaustive neuropsychological battery was also performed to extract the 7 cognitive dimensions of MATRICS initiative. Higher scores on NSS but not on extrapyramidal and catatonic signs showed significant associations with worse cognitive performance in the three study groups. However, the pattern of associations regarding specific cognitive functions was different among the three groups. Moreover, extrapyramidal signs showed significant associations with cognitive impairment only in FEP patients but not in their unaffected siblings and healthy controls. Catatonic signs did not show any significant association with cognitive functioning in the three study groups. These findings add evidence to the associations between motor abnormalities, particularly NSS and extrapyramidal signs, and cognitive impairment in first-episode psychosis patients. In addition, our results suggest that the specific pattern of associations between MAs and cognitive functioning is different in FEP patients from those of the unaffected siblings and healthy subjects.

Cognitive impairment in schizophrenia and depression: A comparison of stability and course

Cognitive deficits are clinically relevant features in schizophrenia and depression, yet little comparative data on changes in both disorders is available. This study compares cognitive performance of inpatients with schizophrenia (N = 52) and unipolar major depression (N = 67) during psychiatric treatment, assessing performance twice: after admission to hospital (acute) and prior to discharge (postacute) on average seven weeks later. A group of healthy controls was tested at comparable intervals. Data was analyzed using a multivariate linear model. Patients with schizophrenia and depression showed significantly impaired performance compared to healthy controls. On follow-up both patient groups showed improved performance. Contrary to expectation, patients with schizophrenia showed greater improvement in verbal memory, visual memory, and psychomotor speed than depressive patients. Verbal fluency presented as a possible candidate to differentiate between both disorders. Similar profiles of generalized cognitive deficits were observed in both patient-groups on acute and postacute assessment, which might indicate trait-like deficits with persistent functional implications in both disorders. Findings do not support assumptions of greater cognitive impairment in schizophrenia compared to depression. A distinction of the disorders on the grounds of cognitive functioning seems to be less specific than presumed.

The impact of chronic psychiatric disorders on cognitive decline

OBJECTIVES

Based on seemingly contradictory results in the existing literature, the objective of our study was to investigate whether older individuals suffering from chronic psychiatric disorders show a more rapid decline in cognitive performances than their non-psychiatric counterparts, or if the pattern of decline through older age is similar in both groups.

METHOD

A total of 820 older adults were selected from the Ageing Multidisciplinary Investigation (AMI) cohort study, which studies health-related issues of people over 65 years old living in rural areas. Among them, 30 suffer from chronic psychiatric disorders. Cognition was assessed with four neuropsychological tests: the Mini-Mental State Examination, the Digit Symbol Substitution Test, the Free and Cued Selective Reminding test and the Isaacs Set Test. Linear mixed models were used to compare the evolution of cognitive performances in the two groups between baseline and the four-year follow-up.

RESULTS

Despite lower performances at baseline, the pattern of cognitive decline of the psychiatric group is similar to that of the control group.

CONCLUSION

As suggested by this study conducted in rural communities, community-dwelling people suffering from chronic psychiatric disorders should not be considered at greater risk of age-related accelerated cognitive decline than the non-psychiatric older population.

Association between DBH 19bp insertion/deletion polymorphism and cognition in schizophrenia with and without tardive dyskinesia

Long-term antipsychotic treatment for schizophrenia is associated with the development of tardive dyskinesia (TD), which is involved in increased cognitive impairment. Dopamine beta-hydroxylase (DBH) gene associated with dopamine and norepinephrine systems influences cognition. Schizophrenia with TD have higher DBH activity than those without TD. This study examined whether DBH5'-insertion/deletion (-Ins/Del) polymorphism could influence cognitive function in schizophrenia with and without TD. The presence of DBH5'-Ins/Del polymorphism was determined in 345 schizophrenia with TD and 397 schizophrenia without TD. The Abnormal Involuntary Movement Scale and Repeatable Battery for Assessment of Neuropsychological Status (RBANS) were used to assess TD severity and cognition. The allele and genotype frequencies of DBH5'-Ins/Del polymorphism did not differ between patients with and without TD (both p>0.05). RBANS total score and subscales did not differ by DBH5'-Ins/Del genotype groups in patients with TD (all p>0.05). However, attention score significantly differed by DBH5'-Ins/Del genotype groups in those without TD (p<0.05). Patients without TD who were Del homozygous had significantly lower attention score than those without TD who were Ins alleles (p<0.05). Immediate memory and attention scores were lower in patients with TD than without TD (both p<0.05). This study indicated that DBH5'-Ins/Del polymorphism may not play a role in the susceptibility to TD and cognitive deficits in schizophrenia with TD, but it may influence cognitive function in schizophrenia with non-TD. Moreover, schizophrenia with TD experienced greater cognitive deficits than those with non-TD, especially in immediate memory and attention.

Cannabidiol Prevents Motor and Cognitive Impairments Induced by Reserpine in Rats

Cannabidiol (CBD) is a non-psychotomimetic compound from Cannabis sativa that presents antipsychotic, anxiolytic, anti-inflammatory, and neuroprotective effects. In Parkinson's disease patients, CBD is able to attenuate the psychotic symptoms induced by L-DOPA and to improve quality of life. Repeated administration of reserpine in rodents induces motor impairments that are accompanied by cognitive deficits, and has been applied to model both tardive dyskinesia and Parkinson's disease. The present study investigated whether CBD administration would attenuate reserpine-induced motor and cognitive impairments in rats. Male Wistar rats received four injections of CBD (0.5 or 5 mg/kg) or vehicle (days 2-5). On days 3 and 5, animals received also one injection of 1 mg/kg reserpine or vehicle. Locomotor activity, vacuous chewing movements, and catalepsy were assessed from day 1 to day 7. On days 8 and 9, we evaluated animals' performance on the plus-maze discriminative avoidance task, for learning/memory assessment. CBD (0.5 and 5 mg/kg) attenuated the increase in catalepsy behavior and in oral movements - but not the decrease in locomotion - induced by reserpine. CBD (0.5 mg/kg) also ameliorated the reserpine-induced memory deficit in the discriminative avoidance task. Our data show that CBD is able to attenuate motor and cognitive impairments induced by reserpine, suggesting the use of this compound in the pharmacotherapy of Parkinson's disease and tardive dyskinesia.

Long-term trajectories of cognitive deficits in schizophrenia: A critical overview

BACKGROUND

Cognitive disturbances are widely pronounced in schizophrenia and schizophrenia spectrum disorders. Whilst cognitive deficits are well established in the prodromal phase and are known to deteriorate at the onset of schizophrenia, there is a certain discrepancy of findings regarding the cognitive alterations over the course of the illness.

METHODS

We bring together the results of the longitudinal studies identified through PubMed which have covered more than 3 years follow-up and to reflect on the potential factors, such as sample characteristics and stage of the illness which may contribute to the various trajectories of cognitive changes.

RESULTS

A summary of recent findings comprising the changes of the cognitive functioning in schizophrenia patients along the longitudinal course of the illness is provided. The potential approaches for addressing cognition in the course of schizophrenia are discussed.

CONCLUSIONS

Given the existing controversies on the course of cognitive changes in schizophrenia, differentiated approaches specifically focusing on the peculiarities of the clinical features and changes in specific cognitive domains could shed light on the trajectories of cognitive deficits in schizophrenia and spectrum disorders.

Extrapyramidal symptoms and cognitive test performance in patients with schizophrenia

BACKGROUND

Movement disorders are common in individuals with schizophrenia, even in those who are not exposed to antipsychotic medications. Extrapyramidal symptoms (EPS) are among the most common abnormal movements in schizophrenia, but their relationship with other features of the illness such as cognition is not well characterized.

METHODS

Three hundred and twenty-five individuals with schizophrenia who were not receiving any antipsychotic or anticholinergic medication and participated in the baseline visit of the Clinical Antipsychotic Treatment of Intervention Effectiveness study were included in the present study. EPSs were assessed using the Simpson-Angus Scale, while cognition was measured with a comprehensive neuropsychological test battery. The relationship between EPS and cognitive test performance was evaluated both dimensionally and categorically.

RESULTS

Greater severity of EPS was significantly associated with worse cognitive test performance evaluated using a composite score. Eighty-six patients were identified as having parkinsonism and these patients performed worse on cognitive tests than non-parkinsonian patients. These findings remained significant even after accounting for other variables such as severity of psychopathology, sedation, akathisia and dyskinesia.

CONCLUSIONS

The present results demonstrate that severity of EPS is reliably linked with poorer scores on tests of cognition. While this may reflect a common pathophysiology underlying neuromotor and neurocognitive deficits, it may also be the case that parkinsonian symptoms such as rigidity and bradykinesia impede test taking ability. Regardless of mechanism, inferences regarding cognitive impairment should take into account the presence of EPS, as well as other variables that may mediate cognitive test findings.

Altered BDNF is correlated to cognition impairment in schizophrenia patients with tardive dyskinesia

BACKGROUND

Long-term antipsychotic treatment for schizophrenia is often associated with the emergence of tardive dyskinesia (TD), which is linked to greater cognitive impairment. Brain-derived neurotrophic factor (BDNF) plays a critical role in cognitive function, and schizophrenia patients with TD have lower BDNF levels than those without TD.

OBJECTIVE

This study examines the BDNF levels, the cognitive function, and the association of BDNF with cognitive function in schizophrenia patients with or without TD.

METHODS

We recruited 83 male chronic patients with (n=35) and without TD (n=48) meeting DSM-IV criteria for schizophrenia and 52 male control subjects. We examined the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and BDNF levels for all subjects. Positive and Negative Symptom Scale (PANSS) and the Abnormal Involuntary Movement Scale (AIMS) were assessed in patients.

RESULTS

BDNF levels were lower in patients with than those without TD (p<0.05). RBANS total score (p<0.01) and subscales of immediate memory, visuospatial/constructional performance, and attention were lower in patients with than those without TD (all p<0.05). BDNF levels were positively associated with immediate memory in patients without TD, but negatively in TD patients (both p<0.05). Multiple regression analysis confirmed that in either TD or non-TD group, BDNF was an independent contributor to immediate memory (both p<0.05).

CONCLUSIONS

BDNF may be involved in the pathophysiology of TD. While the associations between BDNF and cognition in both TD and non-TD patients suggest a close relationship between BDNF and cognition, the different directions may implicate distinct mechanisms between TD and non-TD patients.

Association of altered CuZn superoxide dismutase and cognitive impairment in schizophrenia patients with tardive dyskinesia

Free radical-mediated abnormalities may contribute to the development of tardive dyskinesia (TD) and specific aspects of schizophrenia symptomatology such as cognitive deficits. Superoxide dismutase (SOD), a critical enzyme in the detoxification of superoxide radicals, was found to be abnormal in TD. While most of previous studies focused on the manganese isoform located in mitochondria, this study investigated the activities of isoform CuZnSOD present in the plasma. We recruited 113 male chronic patients with TD (n = 43) and without TD (n = 70) meeting DSM-IV criteria for schizophrenia, and 84 male control subjects. We examined the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), CuZnSOD activity for both the patient and control groups along with total antioxidant status (TAS) and malondialdehyde (MDA) levels in a subset of the cohort. Positive and Negative Symptom Scale (PANSS) and the Abnormal Involuntary Movement Scale (AIMS) were assessed in the patient group. Our results showed lower CuZnSOD activity and TAS levels, but higher MDA levels in patients with TD than those without TD (all p < 0.05). Patients with TD had lower RBANS subscales of Visuospatial/Constructional (p < 0.05) and attention (p < 0.01) than those without TD. Multiple regression analysis showed that in either TD or non-TD group, CuZnSOD was an independent contributor to the attention index of RBANS (both p < 0.05). These results implicated that TD patients suffered greater oxidative stress and cognitive dysfunction than non-TD patients. Oxidative stress could contribute to both TD development and cognitive impairment.

Cognition impairment in schizophrenia patients with tardive dyskinesia: association with plasma superoxide dismutase activity

Long-term antipsychotic treatment for schizophrenia is often associated with the emergence of tardive dyskinesia (TD), and TD presence is also accompanied by more severe cognitive impairment. Oxidative stress-induced damage may be involved in the development of TD and contribute to cognitive deficits in schizophrenia. We examined the role of oxidative stress in relation to TD and cognitive deficits in schizophrenia using plasma manganese superoxide dismutase (MnSOD) as a biomarker. We recruited 83 male chronic patients with (n=32) and without TD (n=51) meeting DSM-IV criteria for schizophrenia, and 58 male control subjects. We examined the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and MnSOD activity for all subjects. Positive and Negative Symptom Scale (PANSS) and the Abnormal Involuntary Movement Scale (AIMS) were assessed in the patients. MnSOD activity was lower in patients with TD than non-TD, and either TD or non-TD group had lower MnSOD levels than controls (all p<0.05). Patients with TD had lower RBANS total (p<0.05) and Visuospatial/Constructional subscale scores than non-TD patients (p<0.01), and either TD or non-TD group scored lower than the controls on all RBANS subscales (all p<0.001) except for the Visuospatial/Constructional index. Multiple regression analysis showed that in either TD or non-TD group, MnSOD was an independent contributor to the RBANS total score (both p<0.05). These findings suggest that TD patients suffered oxidative stress and cognition impairment at a more severe level than non-TD patients. Oxidative stress might serve as a functionally linking node between TD development and cognition dysfunction in schizophrenia.

Novel directions for psychiatric diagnosis: from psychopathology to motor function to monitoring technology

In the light of the recent publication of the DSM-5, there is renewed debate about the relative merit of categorical diagnosis, as laid down in Diagnostic and Statistical Manual of Mental Disorders (DSM) and International Classification of Diseases (ICD) diagnostic manuals. Issues such as validity, usefulness and acceptability of the diagnoses in this manual are increasingly debated. Several alternative possibilities have been suggested including: (i) the introduction of truly cross-cutting dimensional measures, that would facilitate dynamic multidimensional formulations of psychopathology, (ii) the Research Domain Criteria, that may facilitate biological research but move away from clinical symptoms, (iii) a system of personalized diagnosis based on psychopathology as a network of symptoms and contexts, and (iv) enhanced focus on motor alterations, other than catatonia, as a possible additional informative dimension of diagnosis in psychiatry, particularly as a possible marker of underlying neurodevelopmental alterations. We suggest that novel systems of diagnosis are likely to rely more on continuous monitoring of diagnostically relevant information in daily life, complementing retrospective symptom criteria in DSM and ICD. Patients and their families are likely to benefit from these projects, as novel models of diagnosis based on daily life information may be linked more strongly to treatment needs and prognosis.

Course of cognitive deficits in first episode of non-affective psychosis: a 3-year follow-up study

Cognitive dysfunctions are critical determinants of the quality of life and functionality in schizophrenia. Whether the cognitive deficits present at an early stage, are static or change across one's lifespan is still under debate. This study aims to investigate the long-term (3 years) course of cognitive deficits in a large and representative cohort of first episode schizophrenia spectrum patients (N=155),and evaluate their influence on disability. In addition, a healthy control sample (N=43) was also studied for comparison. This study evaluates the performance of patients and controls in a battery of cognitive assessments using baseline, 1-year and 3-year follow-up designs. The results show that, although cognitively outperformed by the controls at any time, the cognitive performance of the patients improved similar to the controls in all cognitive functions except verbal and visual memory. Even though the course of cognitive performance across the sample as a whole was stable, the subgroup of patients who experienced a cognitive decline had worse functionality and lesser amelioration of negative symptoms. Overall, there is no significant deterioration in the cognitive function in a group of first episode schizophrenia spectrum disorder patients, with the possible exception of tasks that were associated with episodic memory. However, patients whose cognitive performance demonstrated a declining trend may present with a poorer progression in terms of clinical and disability variables.

Tardive dyskinesia is associated with greater cognitive impairment in schizophrenia

OBJECTIVE

Schizophrenia is a psychiatric disorder diagnosed by the presence of a number of symptoms with cognitive impairment as a core feature. Long-term antipsychotic treatment is often associated with the emergence of tardive dyskinesia (TD) and the presence of TD is linked to cognitive impairment. This study examined the relationship between TD and cognitive deficits in Chinese patients with schizophrenia.

METHODS

We recruited 206 chronic patients with TD (n=102) and without TD (n=104) meeting DSM-IV criteria for schizophrenia and 104 control subjects who were matched on age, gender, and education. All the patients completed the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), Positive and Negative Symptom Scale (PANSS), and the Abnormal Involuntary Movement Scale (AIMS).

RESULTS

The PANSS total score (p=0.01), N subscore (p=0.006), and AIMS total score (p<0.001) were significantly higher in patients with TD compared to patients without TD. Patients with TD scored lower for visuospatial/constructional, attention, and total index scores (all p<0.001) on the RBANS. AIMS orofacial scores were identified as an independent contributor to RBANS total scores and attention index (p<0.05), whereas AIMS limb and truncal scores were an independent determinant to the visuospatial/constructional index of RBANS (p<0.05).

CONCLUSION

TD was associated with greater cognitive impairment in patients with schizophrenia compared to those without TD. The orofacial and limb-trunk TD specifically appeared to be a risk factor or contributor to the different aspects of cognitive deficits in schizophrenia. The association between schizophrenia and TD may be explained in part by oxidative stress.

Is there evidence for late cognitive decline in chronic schizophrenia?

Schizophrenia (SZP) has been historically referred to as "dementia praecox" because of the recognition that its onset is associated with deficits in memory, attention and visuospatial orientation. We wondered whether there is evidence for additional cognitive decline late in the course of chronic SZP. This review examined the evidence (1) for cognitive decline late in the course of chronic SZP, (2) for how often the late cognitive decline occurs, and (3) whether the cognitive decline in late-life SZP is related to pathophysiology of SZP versus the superimposition of another type of dementia. A PUBMED search was performed combining the MESH terms schizophrenia and dementia, cognitive decline, cognitive impairment and cognitive deficits. A manual search of article bibliographies was also performed. We included longitudinal clinical studies employing standard tests of cognition. Cross-sectional studies and those that did not test cognition through standard cognitive tests were excluded. The initial search produced 3898 studies. Employing selection criteria yielded twenty-three studies. Our data extraction tool included the number of patients in the study, whether a control group was present, the age of patients at baseline and follow-up, the study setting (inpatients versus outpatients), the cognitive tests employed, study duration, and results. Only three longitudinal studies tested for dementia using Diagnostic and statistical manual of mental disorder (DSM) or International classification of disease (ICD) criteria and compared them to controls: two studies demonstrated an increase in the prevalence of dementia and one did not. Twenty longitudinal studies tested for one or more cognitive domains without employing standard criteria for dementia: twelve studies demonstrated a heterogeneous pattern of cognitive decline and eight did not. Studies generally did not control for known risk factors for cognitive impairment such as education, vascular risk factors, apolipoprotein (ApoE) genotype and family history. The evidence for late cognitive decline in SZP is mixed, but, slightly more studies suggest that it occurs. If it occurs, it is unclear whether it is related to SZP or other risks for cognitive impairment. Hence, prospective, longitudinal, controlled studies are needed to confirm that there is progressive cognitive decline in chronic SZP which occurs independent of other risk factors for cognitive impairment.

Neuropsychological performance in older patients with schizophrenia: a meta-analysis of cross-sectional and longitudinal studies

OBJECTIVE

Cognitive deficits are among the most reliable predictors of functional impairment in schizophrenia and a particular concern for older individuals with schizophrenia. Previous reviews have focused on the nature and course of cognitive impairments in younger cohorts, but a quantitative meta-analysis in older patients is pending.

METHOD

A previously used search strategy identified studies assessing performance on tests of global cognition and specific neuropsychological domains in older patients with schizophrenia and age-matched comparison groups. Both cross-sectional and longitudinal studies were included. Potential methodological, demographic, and clinical moderators were analyzed.

RESULTS

Twenty-nine cross-sectional (2110 patients, 1738 comparison subjects) and 14 longitudinal (954 patients) studies met inclusion criteria. Patients were approximately 65 years old, with 11 years of education, 53% male and 79% Caucasian. Longitudinal analysis (range 1-6 years) revealed homogeneity with small effect sizes (d = -0.097) being observed. Cross-sectional analyses revealed large and heterogeneous deficits in global cognition (d = -1.19) and on specific neuropsychological tests (d = -0.7 to -1.14). Moderator analysis revealed a significant role for demographic (age, sex, education, race) and clinical factors (diagnosis, inpatient status, age of onset, duration of illness, positive and negative symptomology). Medication status (medicated vs nonmedicated) and chlorpromazine equivalents were inconsequential, albeit underrepresented.

CONCLUSIONS

Large and generalized cognitive deficits in older individuals with schizophrenia represent a robust finding paralleling impairments across the life span, but these deficits do not decline over a 1-6 year period. The importance of considering demographic and clinical moderators in cross-sectional analyses is highlighted.

Co-opting psychiatry: The alliance between academic psychiatry and the pharmaceutical industry

The Editorial present the arguments that an alliance between academic psychiatry and the pharmaceutical industry is harmful through a critical review of the academic literature and media coverage of activities of the pharmaceutical industry. The industry and the psychiatric profession both gain advantages from promoting biomedical models of psychiatric disturbance and pharmacological treatment. This confluence of interests has lead to the exaggeration of the efficacy of psychiatric drugs and neglect of their adverse effects and has distorted psychiatric knowledge and practice. Academic psychiatry has helped the industry to colonise more and more areas of modern life in order to expand the market for psychotropic drugs. Persuading people to understand their problems as biological deficiencies obscures the social origin and context of distress and prevents people from seeking social or political solutions. Psychiatry has the power to challenge the dominance of the pharmaceutical industry and should put its efforts into developing alternatives to routine drug treatment. Psychiatry needs to disengage from the industry if it wants to make genuine advances in understanding psychiatric disorder and help reverse the harmful social consequences of the widening medicalisation of human experience.

Violence among persons diagnosed with schizophrenia: how pharmacists can help

Violence among those diagnosed with schizophrenia has been reported but is not a diagnostic component of the disorder. The position of the courts regarding fulfillment of the requisite intent to commit violent acts has not been extensively reported. This article discusses the impact of a diagnosis of schizophrenia in an individual and how the pharmacist can help integrate information into the health care system. The recent Supreme Court case of Clark versus Arizona and the older case of Patterson versus Cockrell are discussed with respect to the concept of intent (to commit the act) and the implications this has on an individual in the midst of a psychotic episode. Quality of life, the perception of the stigma associated with a diagnosis of schizophrenia, and pharmacotherapy are briefly discussed. The origin of schizophrenia is multifactorial. Persons with schizophrenia are not innately violent, but alteration in perception may precipitate aggressive acts. Given the complex and diverse nature of schizophrenia and the fact that even with successful pharmacological treatment residual symptoms may still be present, there is a need to provide information to health care practitioners and the court.

Neurological disorders in schizophrenia

Schizophrenia (SZ) is a complex, heterogeneous, and disabling psychiatric disorder that impairs multiple aspects of human cognitive, perceptual, emotional, and behavioral functioning. SZ is relatively frequent (prevalence around 1%), with onset usually during adolescence or early adulthood, and has a deteriorating course. The rapidly growing area of neuroimaging research has has found clear evidence of many cortical and subcortical abnormalities in individuals with SZ. In this article the most recent findings from multiple studies on neurological disorders in SZ are reviewed, and the authors make a strong argument for a neurological basis of the schizophrenic process.

Recent advances in treating cognitive impairment in schizophrenia

INTRODUCTION

Schizophrenia is often associated with chronic disability and poor outcome. In addition to positive symptoms, such as hallucinations and delusions, and negative symptoms including poverty of speech and blunted affect, schizophrenia is also associated with deficits in cognitive function. It has been increasingly recognized that the severity of cognitive impairment is a major determinant of outcome. Therefore, interventions to improve cognitive function also have the capacity to improve quality of life and social and occupational outcomes. Whilst some of the antipsychotic drugs have shown some selective benefits, there is some controversy about the extent of these benefits.

OBJECTIVES

This article provides an overview of research into drugs that might enhance cognition in schizophrenia.

CONCLUSION

Drugs such as modafanil and galantamine are being evaluated, and a number of new drugs are currently in development. Standardized cognitive assessment measures are being developed so studies can be compared more easily. This field is advancing rapidly, but as yet, no widely applicable, evidence-based treatments are available to the clinician.

1-year follow-up study of cognitive function in first-episode non-affective psychosis

The longitudinal course of primary cognitive dysfunction seen in schizophrenia has yet to be fully clarified. Whereas some studies in chronic patients have revealed a progressive decline in cognitive abilities, those studies with first-episode patients have indicated that initial cognitive deficits might remain stable over time. The aim of this study was to examine the longitudinal course of cognitive functioning in patients with a first episode of schizophrenia. 112 patients with a first episode of schizophrenia-spectrum disorders and 22 healthy controls completed clinical and cognitive evaluations at baseline and again after 1 year. An extensive neuropsychological battery that comprised seven cognitive domains was used. Patients and controls improved their cognitive performance in virtually all the cognitive domains after one year. However, patients continued to show marked cognitive deficits after one year, unlike healthy volunteers. The longitudinal cognitive changes were similar in patients and controls in all domains except Verbal Memory (F = 11.67; df = 1; P = 0.001). The increase in cognitive scores found during early phases of the illness seems to be associated to practice-related changes and would not reflect a real cognitive enhancement but rather stability of deficit. Patients' deficits remained stable over time in all cognitive domains except Verbal Memory, in which less performance improvement was found. Further investigations are warranted to discern the variability in patterns of specific cognitive deficits over time.

Cognitive impairment in schizophrenia: a life span perspective

Cognitive impairment is a core Feature oF schizophrenia. The evolution oF cognitive impairment over the liFe span may clariFy whether schizophrenia is best characterized as a neurodevelopmental or neurodegenerative disorder. Children who later develop schizophrenia show delayed language acquisition, intellectual impairment, and poorer academic perFormance than peers. These premorbid intellectual deFicits may worsen beFore illness onset. Although patients show pervasive intellectual impairment at First episode, this deFicit does not appear to worsen through middle age. Gerontological patients remain poorly characterized, but a subset oF chronic, institutionalized patients may show Further intellectual and Functional decline in old age. From a cognitive perspective, schizophrenia may be best viewed as a neurodevelopmental disorder initiated by genetic or environmental Factors in the prenatal period. These early changes may contribute to premorbid cognitive impairment and to subsequent disturbances oF neural connectivity and transmission.

Orofacial dyskinesia, frontal lobe dysfunction, and coping in older people with psychosis

OBJECTIVE

To investigate whether orofacial tardive dyskinesia (OTD) is associated with frontal lobe dysfunction and whether either are related to the coping abilities independent of psychiatric symptoms in older people with psychotic disorders.

METHODS

A total of 52 patients, aged over 65 years or over, who satisfied International Classification of Diseases, Tenth Revision criteria for psychotic disorders (F20-F29) were recruited into the study. OTD was measured using the Abnormal Involuntary Movements Scale and Waddington et al.'s (1993) criteria. Neuropsychological measures were specifically selected to assess different aspects of frontal function and coping was measured using a semistructured interview. Psychiatric symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS).

RESULTS

Patients with OTD showed more severe global cognitive impairment compared to patients without OTD. Group differences on measures of frontal lobe dysfunction were not maintained following adjustment for global cognitive impairment. Patients with OTD did not differ from patients without OTD on coping measures. Scores on the general psychopathology subscale of the PANSS, which includes symptoms associated with depression and anxiety, consistently predicted patients' negative perceptions of stressors and appraisals of coping, but cognitive impairment did not predict coping independent of symptoms.

CONCLUSION

The association between coping and general psychopathology in older patients with psychosis warrants further investigation as both variables may be amenable to psychological interventions.

Very poor outcome schizophrenia: clinical and neuroimaging aspects

In spite of significant advances in treatment of patients with schizophrenia and continued efforts towards their deinstitutionalization, a considerable group of patients remain chronically hospitalized or otherwise dependent on others for basic necessities of life. It has been proposed that these patients belong to a distinct etiopathological subgroup, termed Kraepelinian, whose course of illness may be progressive and resistant to treatment. Indeed, longitudinal studies appear to show that elderly Kraepelinian patients follow a course of rapid cognitive and functional deterioration, commensurate with a dementing process, and that their poor functional status is closely correlated with the cognitive deterioration. Recent neuroimaging studies described a pattern of posteriorization of grey and white matter deficits with poor outcome in schizophrenia, and produced a constellation of findings implicating primary processing of visual and auditory information as central to the impaired functional status in this patient group. These studies are summarized in detail in this review and future directions for neuroimaging assessment of very poor outcome patients with schizophrenia are suggested.

Antipsychotic-induced tardive dyskinesia and the Ser9Gly polymorphism in the DRD3 gene: a meta analysis

BACKGROUND

A polymorphic site in the gene encoding the dopamine 3 receptor (DRD3) resulting in a serine (Ser) into glycine (Gly) substitution has been shown to affect dopamine binding affinity, and may contribute to individual differences in susceptibility to antipsychotic-induced tardive dyskinesia (TD).

METHODS

A Medline, EMBASE and PsychINFO search of literature published between 1976 and March 2005 yielded 11 studies from which data were extracted for calculation of pooled estimates using meta-analytic techniques.

RESULTS

The Gly allele increased the risk relative to the Ser allele (OR=1.17; 95% CI: 1.01-1.37) with evidence of publication bias. No significant genotype effects were apparent.

CONCLUSIONS

TD may be associated with functional variation in the DRD3 allele. However, caution is required in interpreting this finding, as there is evidence of publication bias, genetic methodology has shortcomings, and the relation between antipsychotics, schizophrenia and TD is complex.

Paul E. Meehl's influence on experimental psychopathology: fruits of the nexus of schizotypy and schizophrenia, neurology, and methodology

Paul E. Meehl made numerous contributions to clinical science and a hallmark of many of these contributions was their integrative nature. Meehl's positions on complex topics, especially one such as schizophrenia, were reflective of input from a variety of disciplines and levels of analysis. In this essay the authors focus on Meehl's uniquely rich contribution to our understanding of schizophrenia through his theoretical model of schizotypy, his abiding interest in exploring neurologically based indicators of schizophrenia liability and encouragement to others to pursue such indicators, and his passion for rigorous research methodology. Meehl's contributions in each of these areas continue to influence the direction and research strategies used in experimental psychopathology to illuminate the fundamental nature of schizophrenia. These contributions have also shaped inquiry into many other psychopathological entities.

Tardive dyskinesia and antipsychotics: a 5-year longitudinal study of frequency, correlates and course

The present study comprised a naturalistic, multicentre, 5-year study of course and correlates of tardive dyskinesia (TD). One hundred and sixty-six patients treated with risperidone were included during 1995/96 and followed once a year for 5 years. Mean age at inclusion was 38 years, and mean illness duration was 12 years. Tardive dyskinesia was assessed by the Abnormal Involuntary Movement Scale, and each patient's cognitive function was tested with a comprehensive computerised test battery. At study entry, 14% had TD according to a criterion index. Fifty percent were aware of it, but few reported distress. Age and sex did not correlate with TD, but schizophrenia and bipolar diagnoses did. The presence and intensity of TD correlated with all Positive and Negative Syndrome Scale for Schizophrenia symptom dimensions except the affective factor, but not with type of medication or chlorpromazine-equivalent levels. Tardive dyskinesia patients were cognitively impaired in tests reflecting mental speed, but not in other cognitive modalities. Over the 453 patient years of exposure, five patients developed TD and 14 became free of it. Our findings support the view that TD: (i) is a dynamic phenomenon; (ii) is only partly drug-induced; (iii) has a mild course during treatment with modern neuroleptics; and (iv) appears to have some correlation with mental slowness.

Disability reduction in elderly patients with schizophrenia

This article reviews a frequently overlooked subject, the topic of schizophrenia in late life. By examining the available literature on schizophrenia in this particular population, we hope to provide clinicians with a better understanding of the distinguishing characteristics, course, and optimal treatments of this disease in elderly patients. The validity of the concept of symptom "burn out" is discussed and the cognitive changes seen in schizophrenia as patients age are examined. Similarities and differences between late-onset schizophrenia and early-onset schizophrenia in aging patients are compared. The similarities and differences between schizophrenia and dementia in the elderly are also discussed. Finally, treatments for the illness, including both typical and atypical antipsychotic treatments, as well as nonpharmacological intervention strategies, along with their advantages and disadvantages, are reviewed.

Neuropsychological functioning in first-break, never-medicated adolescents with psychosis

The purpose of the current study was to examine neuropsychological functioning in a group of never-medicated first-break adolescents with psychosis. It is the first report of cognition in a sample of adolescents with psychosis in which all patients were drug-naive. Twenty-nine adolescent patients (mean age = 16.07; SD = 2.00; 15 male and 14 female patients) experiencing their first psychotic episode and 17 age-matched and sex-matched normal volunteers (mean age = 16.88; SD = 2.39; 9 male and 8 female subjects) were recruited and assessed with a neuropsychological battery. Measures of attention, memory, language, executive functioning, perceptual motor processing, and motor speed were obtained. Psychiatric symptomatology, estimated verbal IQ, and parental socioeconomic status were also determined. Patients with psychosis were significantly more impaired than normal volunteers; effect sizes were greatest in the areas of executive functioning, attention, and memory, and significantly smaller in areas of language, perceptual motor processing, and motor speed. The pattern was not altered when differences in verbal IQ and parental socioeconomic status were controlled. Sex and age interactions indicated that younger male patients were particularly impaired. The findings demonstrate neuropsychological deficits in adolescents with psychosis and suggest that cognitive deficits are core symptoms in psychotic disorders.

Accelerated age-related decline of visual information processing in first-degree relatives of persons with schizophrenia

A recent cross-sectional study suggested that persons with schizophrenia experience an accelerated age-related decline in performance on the Span of Apprehension task, a visual information processing paradigm. However, this study was not able to determine if such decline was primarily related to genetic loading for schizophrenia, as the decline may have been related to chronic neuroleptic use or other confounds found when studying persons with schizophrenia directly. To help address this question, the current study examined healthy first-degree relatives of persons with schizophrenia over a wide age range to investigate whether such age effects may be related to genetic loading for schizophrenia. Twenty-eight healthy first-degree relatives of persons with schizophrenia (ages 21-72) and 31 healthy controls (ages 19-75) were evaluated using the Span of Apprehension task with cross-sectional methodology. Results replicated and extended the earlier report examining persons with schizophrenia, as the data indicated a statistically significant accelerated age-related decline in performance in the relatives. While the study is limited by cross-sectional methodology, it suggests a genetically driven, age-related decline in visual information processing related to schizophrenia and informs future longitudinal studies that can more definitively address such a possibility.

Relationship of good and poor Wisconsin Card Sorting Test performance to illness duration in schizophrenia: a cross-sectional analysis

The authors investigated whether schizophrenic patients with good and poor performance on the Wisconsin Card Sorting Test (WCST) showed cognitive modifications related to duration of illness. Of the 154 patients evaluated with the WCST, 56 subjects had normal or mildly impaired performance and 98 showed impairment on the basis of the number of categories achieved (0-3 categories = poor performance). These subsamples were then cross-sectionally divided into three subsamples depending on length of illness (< 5 years, 6-10 years, > 10 years). The inclusion of 69 healthy controls allowed the effect of age to be taken into account. The schizophrenic group as a whole and the group of poor performers did not show differences in any of the WCST indices related to length of illness. Good performers instead showed improvement on the intermediate length-of-illness group (6-10 years of illness), and then decline in the third one (> 10 years). Good performers only showed a positive significant correlation between age, age at onset, educational level and successful WCST performance. Results for the poor performers support the hypothesis of no progressive 'deteriorating' course of schizophrenia, while good performers show an unstable pattern of cognitive functions. These data support the hypothesis that cognitive deficits associated with schizophrenia cannot be considered a unitary trait, but emerge along different hypothetical trajectories.

Gender related differences in clinical characteristics and hospital based resource utilization among older adults with schizophrenia

OBJECTIVE

This report is an analysis of gender related differences in clinical characteristics and hospital based health resource utilization among older adults with schizophrenia and schizoaffective disorder in an acute care, state hospital over a one-year period.

METHODS

This retrospective record review is an analysis of age of illness onset, psychiatric and medical comorbidity, hospital utilization, and psychotropic medication use.

RESULTS

There were a total of 66 individuals with either schizophrenia or schizoaffective disorder. Mean age of this group was 55.2 +/- 4.62 years. Women were significantly over-represented among individuals with late onset schizophrenia and schizoaffective disorder. Men with schizophrenia had more comorbid substance abuse compared to women with schizophrenia (p < 0.05). Women and men did not differ significantly in hospital length of stay, amount or type of antipsychotic medication prescribed, or in utilization of seclusion/restraint in hospital. Both genders had substantial utilization of antipsychotic medication. Use of conventional antipsychotic medication monotherapy was always associated with use of anti-extrapyramidal symptom (anti-EPS) medication, while use of atypical antipsychotic medication monotherapy was more rarely associated with use of anti-EPS medication.

CONCLUSIONS

In later life, women and men may have some areas of differing health care needs. Women in particular may benefit from psychoeducational approaches that address the experience of psychiatric illness of relatively recent onset (for example, symptom identification and acceptance of illness). Men may benefit from particular emphasis on treatment of comorbid substance abuse disorders.

Neuropsychological function in subjects with psychotic and affective disorders. Relationship to diagnostic category and duration of illness

OBJECTIVE

To explore the links between neuropsychological performance, diagnostic category and duration of illness in subjects with psychotic and affective disorders.

METHODS

Memory and executive abilities were tested in consecutively admitted patients with schizophrenia (N = 20), other non-schizophrenic psychotic disorders (N = 29), bipolar disorder (N = 33) and major depression (N = 19).

RESULTS

Subjects with schizophrenia had poorer global memory performances than subjects with major depression, and poorer delayed verbal memory abilities than those from the other three diagnostic groups. Executive abilities explored by the Stroop test and the Wisconsin Card Sorting Test did not differ between diagnostic groups. Neuropsychological performances were not influenced by previous duration of illness.

CONCLUSION

Memory deficits are the most discriminatory cognitive features between subjects with schizophrenia and those with other psychotic or mood disorders. The fact that cognitive deficits are static whatever the diagnostic group indirectly suggests that they may have a neurodevelopmental origin in subjects with schizophrenia, but perhaps also in subjects with other psychotic and mood disorders.

Tardive dyskinesia is associated with impaired retrieval from long-term memory: the Curaçao Extrapyramidal Syndromes Study: IV

Tardive dyskinesia may be associated with cognitive dysfunction. It is not clear whether this dysfunction occurs in the form of a global or specific cognitive deficit. A cross-sectional study was conducted in a well-defined catchment area (Curaçao, The Netherlands Antilles). All schizophrenic inpatients who had been taking neuroleptic medication for at least 3months and who were younger than 65years were included (n=53). Tardive dyskinesia was assessed with the Abnormal Involuntary Movement Scale. The neuropsychological assessment comprised tests of memory, executive function, and speed of information processing. Of the six cognitive measures, only delayed recall was significantly associated with orofacial dyskinesia. Limb-truncal dyskinesia was not associated with any of the cognitive measures. The pattern of memory impairment is consistent with there being a frontal-subcortical disturbance in orofacial dyskinesia. The results underscore the importance of using specific cognitive test procedures in the search for the cognitive correlates of dyskinesia.

Prevalence and correlates of parkinsonism in an institutionalized population of geriatric patients with chronic schizophrenia

BACKGROUND

Geriatric patients with chronic schizophrenia are at increased risk for parkinsonism and cognitive impairment, but the relationship between the two has been insufficiently studied.

OBJECTIVES

(1) To determine the prevalence of parkinsonism in a cohort of institutionalized geriatric patients with chronic schizophrenia (N=79). (2) To examine the relationship of parkinsonism to potentially relevant variables including cognitive functioning, positive and negative symptoms, sex, age, age at first hospitalization, psychopharmacological regimen and tardive dyskinesia (TD).

METHOD

Tremor, rigidity and bradykinesia were rated on a five-point severity scale. Clinically significant parkinsonism was defined by the unambiguous presence of at least two of those signs. TD was assessed with the Modified Simpson Dyskinesia Scale. Schizophrenic symptoms were rated with the Positive and Negative Syndrome Scale, and cognitive functioning with the Mini-Mental State Examination and the Consortium to Establish a Registry for Alzheimer's Disease battery.

RESULTS

The prevalence of parkinsonism was 19% and was significantly higher in women than in men. Age was a significant predictor of parkinsonism. Independent of age, bradykinesia was significantly correlated with MMSE, fluency and naming. Tremor, rigidity and medication status did not correlate with any cognitive variable assessed. Cognitive measures did not differ between subjects meeting and not meeting criteria for clinically significant parkinsonism. Rigidity and bradykinesia were significantly correlated with negative symptoms but no parkinsonism sign correlated with positive symptoms. Twelve subjects received ratings consistent with both TD and parkinsonism; however, no parkinsonian variable predicted the co-occurrence of TD.

CONCLUSIONS

The present correlations suggest potential overlap among the neural substrates for bradykinesia, cognitive impairment and negative symptoms; however, further research is required to clarify that issue.

Cognition and neuropathology in schizophrenia

Clinical, neuropsychological and neuropathological avenues of research have advanced in concert to increase our understanding of schizophrenia. Progress in four general areas of investigation will be reviewed: (i) fronto-temporal-limbic dysfunction; (ii) abnormal connectivity or 'miswiring'; (iii) aberrant neurodevelopment; and (iv) neurodegeneration and neural injury. The challenge for post-mortem research is to identify the molecular pathways in which abnormalities culminate in the highly diverse features of the disorder. Candidate pathways must be able to account for the developmental and deteriorative clinical profiles and the global and focal neuropsychological deficits, as well as the various patho-anatomical abnormalities that indicate aberrant cytoarchitecture and connectivity in the absence of neurodegeneration or other obvious evidence of postmaturational neural injury.

The neuropathology of schizophrenia. A critical review of the data and their interpretation

Despite a hundred years' research, the neuropathology of schizophrenia remains obscure. However, neither can the null hypothesis be sustained--that it is a 'functional' psychosis, a disorder with no structural basis. A number of abnormalities have been identified and confirmed by meta-analysis, including ventricular enlargement and decreased cerebral (cortical and hippocampal) volume. These are characteristic of schizophrenia as a whole, rather than being restricted to a subtype, and are present in first-episode, unmedicated patients. There is considerable evidence for preferential involvement of the temporal lobe and moderate evidence for an alteration in normal cerebral asymmetries. There are several candidates for the histological and molecular correlates of the macroscopic features. The probable proximal explanation for decreased cortical volume is reduced neuropil and neuronal size, rather than a loss of neurons. These morphometric changes are in turn suggestive of alterations in synaptic, dendritic and axonal organization, a view supported by immunocytochemical and ultrastructural findings. Pathology in subcortical structures is not well established, apart from dorsal thalamic nuclei, which are smaller and contain fewer neurons. Other cytoarchitectural features of schizophrenia which are often discussed, notably entorhinal cortex heterotopias and hippocampal neuronal disarray, remain to be confirmed. The phenotype of the affected neuronal and synaptic populations is uncertain. A case can be made for impairment of hippocampal and corticocortical excitatory pathways, but in general the relationship between neurochemical findings (which centre upon dopamine, 5-hydroxytryptamine, glutamate and GABA systems) and the neuropathology of schizophrenia is unclear. Gliosis is not an intrinsic feature; its absence supports, but does not prove, the prevailing hypothesis that schizophrenia is a disorder of prenatal neurodevelopment. The cognitive impairment which frequently accompanies schizophrenia is not due to Alzheimer's disease or any other recognized neurodegenerative disorder. Its basis is unknown. Functional imaging data indicate that the pathophysiology of schizophrenia reflects aberrant activity in, and integration of, the components of distributed circuits involving the prefrontal cortex, hippocampus and certain subcortical structures. It is hypothesized that the neuropathological features represent the anatomical substrate of these functional abnormalities in neural connectivity. Investigation of this proposal is a goal of current neuropathological studies, which must also seek (i) to establish which of the recent histological findings are robust and cardinal, and (ii) to define the relationship of the pathological phenotype with the clinical syndrome, its neurochemistry and its pathogenesis.

Tardive dyskinesia in a chronically institutionalized population of elderly schizophrenic patients: prevalence and association with cognitive impairment

BACKGROUND

Chronically hospitalized geriatric inpatients with schizophrenia are at particular risk for both tardive dyskinesia (TD) and cognitive impairment but have been insufficiently studied in this regard. Similarly, the relationship between TD and cognitive impairment has not be adequately addressed in this population.

OBJECTIVES

(1) To determine the prevalence of TD in a cohort of chronically institutionalized schizophrenic geriatric inpatients. (2) To examine the relationship between the manifestations of TD in various body regions and several potentially related variables including current pharmacological regimen, age, age at first hospitalization and cognitive status.

METHOD

TD was assessed by the Modified Simpson Dyskinesia Scale and cognitive status by the Mini-Mental State Examination (MMSE). The relationship between manifestations of TD and other variables was examined by t-tests, ANOVA, MANOVA and correlational analysis.

RESULTS

The prevalence of TD was 60%. Prevalence increased with age but was not related to current antipsychotic or anticholinergic regimen. Mean MMSE score did not differ between groups of patients with and without TD as defined by the criteria of Schooler and Kane (1982); however, the mean MMSE score was significantly (p < 0.0004) lower in subjects with orofacial TD as defined by Waddington and Youssef (1996), and the difference was not entirely accounted for by the older age of the latter group.

CONCLUSIONS

TD and cognitive impairment both increase with age. However, TD alone does not account for the severity of cognitive impairment in this population. The present study provides further support for the hypothesis that the correlation between TD and cognitive impairment holds primarily for the orofacial manifestations of TD.

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.

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.

Incidence and risk factors for severe tardive dyskinesia in older patients

BACKGROUND

Severe tardive dyskinesia (TD) represents a serious and potentially disabling movement disorder, yet relatively little is known about the incidence of and risk factors for severe TD.

METHOD

We report the results of a longitudinal prospective incidence study of severe TD in 378 middle-aged and elderly neuropsychiatric patients. Psychiatric, neuropsychological, pharmacological and motor variables were obtained at intake and at regular intervals for 36 months.

RESULTS

The cumulative incidence of severe TD was 2.5% after one year, 12.1% after two years, and 22.9% after three years. Individual univariable Cox regression analyses were conducted to identify demographic, psychiatric, motor and pharmacological predictors of severe TD. Results indicated that higher daily doses of neuroleptics at study entry, greater cumulative amounts of prescribed neuroleptic, and greater severity of worsening negative symptoms were predictive of severe TD.

CONCLUSIONS

These findings suggest that conventional neuroleptics may be prescribed to older patients only when necessary and at the lowest effective dosage. Additional caution is recommended in patients exhibiting negative symptoms.

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

Though conceptualised originally as a deteriorating disorder, some contemporary studies have been interpreted as challenging these foundations; more radically, it has been proposed that schizophrenia may be a 'static encephalopathy' of neurodevelopmental origin. The argument offered here is that schizophrenia is indeed a neurodevelopmental disorder, but that this is not in itself antithetical to later disease progression. Rather, the onset of psychosis may reflect the maturationally-mediated triggering of an active disease process that is associated with progressive deterioration unless attenuated by antipsychotic drugs. A developmental trajectory is proposed to link first or early second trimester dysplasia to the chronic course of the illness; from this, it is argued that schizophrenia is inherently a progressive disorder but that antipsychotic drugs may act to ameliorate this progressive component and thus confer on the disease course some of the characteristics of a 'static encephalopathy'. The 'true' natural history of an illness cannot be determined from studies in treated populations.