Combination treatments for schizophrenia

Sleep Homeostatic and Waking Behavioral Phenotypes in Egr3-Deficient Mice Associated with Serotonin Receptor 5-HT2 Deficits

STUDY OBJECTIVE

The expression of the immediate early gene early growth response 3 (Egr3) is a functional marker of brain activity including responses to novelty, sustained wakefulness, and sleep. We examined the role of this gene in regulating wakefulness and sleep.

METHODS

Electroencephalogram/electromyogram (EEG/EMG) were recorded in Egr3-/- and wild-type (WT) mice during 24 h baseline, 6 h sleep disruption and 6 h recovery. Serotonergic signaling was assessed with 6 h EEG/EMG recordings after injections of nonselective 5-HT2 antagonist (clozapine), selective 5-HT2 antagonists (5-HT2A; MDL100907 and 5-HT2BC; SB206553) and a cocktail of both selective antagonists, administered in a randomized order to each animal.

RESULTS

Egr3-/- mice did not exhibit abnormalities in the timing of wakefulness and slow wave sleep (SWS); however, EEG dynamics in SWS (suppressed 1-3 Hz power) and in quiet wakefulness (elevated 3-8 Hz and 15-35 Hz power) differed in comparison to WT-mice. Egr3-/- mice showed an exaggerated response to sleep disruption as measured by active wakefulness, but with a blunted increase in homeostatic sleep drive (elevated 1-4 Hz power) relative to WT-mice. Egr3-/-mice exhibit greatly reduced sedative effects of clozapine at the electroencephalographic level. In addition, clozapine induced a previously undescribed dissociated state (low amplitude, low frequency EEG and a stable, low muscle tone) lasting up to 2 h in WT-mice. Egr3-/- mice did not exhibit this phenomenon. Selective 5-HT2A antagonist, alone or in combination with selective 5-HT2BC antagonist, caused EEG slowing coincident with behavioral quiescence in WT-mice but not in Egr3-/- mice.

CONCLUSION

Egr3 has an essential role in regulating cortical arousal, wakefulness, and sleep, presumably by its regulation of 5-HT2 receptors.

Double-blind donepezil-placebo crossover augmentation study of atypical antipsychotics in chronic, stable schizophrenia: a pilot study

Thirteen outpatients with chronic but stable schizophrenia received donepezil and placebo augmentation of their maintenance antipsychotic medication regimen. Each subject received in a randomized, counterbalanced order 1) donepezil 5 mg for 6 weeks then donepezil 10 mg for six weeks and 2) placebo donepezil for 12 weeks. Serial ratings of the Positive and Negative Symptom Scale (PANSS) [Kay, S.R., Fiszbein, A., Opler, L.A., 1987. The positive and negative syndrome scale (PANSS) for schizophrenia. Schizophrenia Bulletin 13(2): 261-276] were performed by a trained rater blind to the donepezil order and condition: at baseline, 12 weeks and 24 weeks. On donepezil as compared to baseline or placebo, there was a significant improvement in PANSS negative scores (p=.018, n=13). These results are discussed with respect to other studies using cholinesterase inhibitors as an augmentation strategy in schizophrenia.

The International Society for Developmental Psychobiology annual meeting symposium: Impact of early life experiences on brain and behavioral development

Decades of research in the area of developmental psychobiology have shown that early life experience alters behavioral and brain development, which canalizes development to suit different environments. Recent methodological advances have begun to identify the mechanisms by which early life experiences cause these diverse adult outcomes. Here we present four different research programs that demonstrate the intricacies of early environmental influences on behavioral and brain development in both pathological and normal development. First, an animal model of schizophrenia is presented that suggests prenatal immune stimulation influences the postpubertal emergence of psychosis-related behavior in mice. Second, we describe a research program on infant rats that demonstrates how early odor learning has unique characteristics due to the unique functioning of the infant limbic system. Third, we present work on the rodent Octodon degus, which shows that early paternal and/or maternal deprivation alters development of limbic system synaptic density that corresponds to heightened emotionality. Fourth, a juvenile model of stress is presented that suggests this developmental period is important in determining adulthood emotional well being. The approach of each research program is strikingly different, yet all succeed in delineating a specific aspect of early development and its effects on infant and adult outcome that expands our understanding of the developmental impact of infant experiences on emotional and limbic system development. Together, these research programs suggest that the developing organism's developmental trajectory is influenced by environmental factors beginning in the fetus and extending through adolescence, although the specific timing and nature of the environmental influence has unique impact on adult mental health.

Neurocognitive performance and negative symptoms: are they equal in explaining disability in schizophrenia outpatients?

OBJECTIVE

The aim of this study is to assess if cognitive variables and symptom dimensions can predict disability in a sample of outpatients with schizophrenia.

METHOD

A cross-sectional sample of 113 individuals with a diagnosis of schizophrenia (DSM-IV criteria) was selected from a computerized register of five Community Mental Health Centers. Patients were assessed by two trained psychologists, with a neuropsychological battery comprising measures for verbal memory, attention, operative memory and abstraction and flexibility functions. Symptoms were assessed with the Positive and Negative Syndrome Scale (PANSS); a socio-demographic and clinical questionnaire, comprising the Disability Assessment Scale (DAS), was also completed. Test scores were standardized (t scores) to performance of healthy controls. To assess the relationship between clinical and sociodemographic factors and disability and cognitive functioning Pearson's correlation coefficients were computed. In order to establish the predictive capacity of the cognitive, clinical and symptom variables on disability linear regression models were fitted.

RESULTS

Mean age of patients was 41.6 years and 68% were male. Higher ratings in the negative dimension were associated with more cognitive deficits. Association with the positive dimension was present but less strong. All disability areas, except for disability in occupational functioning, were partially explained by the negative dimension. Disability in family functioning was also partially explained by attention and number of admissions since onset.

CONCLUSION

Negative symptoms are the major source of disability of our sample and are also associated to cognitive functioning. The present findings suggest that further investigation on the mediators between clinical and social outcomes may help to design specific treatments to reduce disability.

Four symptom dimensions in outpatients with schizophrenia

OBJECTIVE

The aim of this study was to assess the dimensional structure of the Positive and Negative Symptoms Scale (PANSS) to identify the psychopathological profiles of outpatients with schizophrenia.

METHOD

Two hundred and thirty-one persons with schizophrenia (DSM-IV criteria) were randomly selected from a register that included all patients under treatment in 5 mental health care centers in Spain. Patients were evaluated with a sociodemographic and clinical questionnaire, the PANSS, the Disability Assessment Scale short version, and the Global Assessment Functioning Scale. A principal component analysis with oblimin rotation was used to examine the factor structure of the PANSS. Different statistical analyses were done to compare the resulting factors with clinical, disability, and social functioning variables.

RESULTS

Mean age of patients included was 39.6 years and approximately 65% were male. Four principal components, each of them with eigenvalues greater than 1.5, accounted for 56.22% of the variance. After oblimin rotation, these factors were identified as the Negative (32.48%), Excitement (11.29%), Affective (7.45%), and Positive (5.01%) components. Significant positive correlation between age and the negative dimension was found. Also, we observed significant negative correlations between global assessment functioning and negative and positive dimensions. Total disability was significantly positively related to all dimensions.

CONCLUSION

Positive and negative dimensions are common in all principal component analysis results, but we also found affective and excitement dimensions. The present finding suggests that further investigation of symptom dimensions may help to improve symptom-specific treatments; future research should focus on the design of new treatment programs considering these results.

Use of combinations of antipsychotics: McLean Hospital inpatients, 2002

BACKGROUND

The empirical use of combinations of antipsychotic agents appears to be increasing with little research support for the relative efficacy, safety or cost-effectiveness of this practice. Such treatment was evaluated in hospitalized psychiatric patients.

METHODS

Samples of consecutive inpatients treated with > or = 2 ('polytherapy') vs 1 antipsychotic ('monotherapy') were matched on age, sex, diagnosis and admission clinical ratings, and these groups were compared on total daily chlorpromazine-equivalent doses, days in hospital, and changes in clinical ratings between admission and discharge.

RESULTS

The study sample included 69 polytherapy and 115 well-matched monotherapy subjects. Despite matching for initial CGI and GAF ratings, polytherapy was associated with high PANSS subscale scores of positive symptoms among affective psychosis, and relatively greater PANSS subscale ratings of excitement-agitation among patients diagnosed with schizophrenia. Estimated clinical improvement during hospitalization was similar among poly- and monotherapy patients, but total daily CPZ-eq doses at discharge averaged twice-greater with polytherapy, and hospitalization lasted 1.5 times longer.

CONCLUSIONS

Antipsychotic polytherapy as well as the types of agents combined may reflect clinician responses to particular symptom patterns. The value of specific combinations of antipsychotic agents and their comparison with monotherapies requires specific, prospective, randomized and well-controlled trials that consider matching on clinical characteristics and truly comparable doses across regimens.