Cognitive-Behavioral Social Skills Training for patients with late-life schizophrenia and the moderating effect of executive dysfunction

The objectives of this study are to test the efficacy of Cognitive-Behavioral Social Skills Training (CBSST) in enhancing social function in a sample of older patients with schizophrenia, and to assess whether baseline cognition moderates response to CBSST. To address these objectives, we conducted a randomized controlled trial of 63 participants, randomized 1:1 into CBSST or Treatment-As-Usual (TAU). The setting was a community-based geriatric mental health outpatient clinic in Toronto, Ontario, Canada. Data were collected at baseline, and week 18, 36 and 52, between June 2008 and May 2014. Participants were outpatients, aged 60 or older, with a diagnosis of schizophrenia or schizoaffective disorder and no evidence of dementia or other conditions associated with cognitive or functional impairment. The intervention was a weekly group CBSST for 36 weeks. Cognition, including executive function, was assessed at baseline. Modified total score on the Independent Living Skills Survey (ILSS) at 18, 36, and 52 weeks was the primary outcome measure. In a linear mixed model analysis, the ILSS trajectory was better in the CBSST group than the TAU group, with significantly better function at 36 (Cohen's d = 0.75) and 52 weeks (Cohen's d = 0.92). Baseline executive dysfunction moderated CBSST response, whereby participants with more severe executive dysfunction experienced the most improvement in ILSS. CBSST was efficacious in patients with late-life schizophrenia and prevented decline in social function over a one-year period. CBSST was most beneficial for patients with more severe executive dysfunction, i.e., those who needed skills training the most.

Impaired illness awareness in schizophrenia and posterior corpus callosal white matter tract integrity

Impaired illness awareness (Imp-IA) in schizophrenia is associated with interhemispheric imbalance, resulting in left hemisphere dominance, primarily within the posterior parietal area (PPA). This may represent an interhemispheric “disconnection syndrome” between PPAs. To test this hypothesis, we aimed to determine if diffusion-based measures of white matter integrity were disrupted in the corpus callosal tracts linking PPAs (i.e., splenium) in patients with Imp-IA in schizophrenia. T1-weighted and diffusion-weighted scans were acquired on a 1.5T GE scanner for 100 participants with a DSM-IV-TR diagnosis of schizophrenia and 134 healthy controls aged 18 to 79 years. The corpus callosal white matter tracts were compared among patients with Imp-IA (n = 40), intact illness awareness (n = 60), and healthy controls. White matter disruption was measured with fractional anisotropy (FA) and mean diffusivity (MD). Group differences in FA were found in the splenium, with patients with Imp-IA having the lowest FA, which remained significant after controlling for sex, age, global cognition, and premorbid intelligence. No group differences in MD were observed. Splenial white matter tracts of the corpus callosum appear compromised in patients with Imp-IA. Transcallosal interhemispheric PPA white matter disruption may represent a “disconnection syndrome”, manifesting as Imp-IA in schizophrenia. Future studies are required to investigate the effects of noninvasive brain stimulation interventions, such as transcranial direct current or magnetic stimulation, on Imp-IA in association with white matter changes in patients with schizophrenia.

Vestibular stimulation improves insight into illness in schizophrenia spectrum disorders

Impaired insight into illness (IMP-INS) is common among individuals with schizophrenia spectrum disorders (SSD), contributing to medication nonadherence and poor clinical outcomes. Caloric vestibular simulation (CVS) is typically used to assess peripheral vestibular system function. Left cold CVS is also a transiently effective treatment for IMP-INS and hemineglect secondary to right brain hemisphere stroke, and possibly for IMP-INS and mood stabilization in patients with SSD. Participants with SSD and moderate-to-severe IMP-INS participated in an exploratory double blind, crossover, randomized controlled study of the effects of CVS on IMP-INS. Participants sequentially received all experimental conditions-left cold (4°C), right cold, and body temperature/sham CVS-in a random order. Repeated measures ANOVA were performed to compare changes in IMP-INS, mood and positive symptom severity pre and 30min post CVS. A significant interaction was found between CVS condition, time, and body temperature nystagmus peak slow phase velocity (PSPV) for IMP-INS, indicating that single session left cold CVS transiently improved IMP-INS while right cold CVS may have worsened IMP-INS, particularly in participants with greater vestibular reactivity (i.e. higher PSPV) to body temperature CVS. The procedure's effectiveness is attributed to stimulation of underactive right hemisphere circuits via vestibular nuclei projections to the contralateral hemisphere.

Insight Into Illness and Cognition in Schizophrenia in Earlier and Later Life

OBJECTIVE

Impaired insight into illness in schizophrenia is associated with illness severity and deficits in premorbid intellectual function, executive function, and memory. A previous study of patients aged 60 years and older found that illness severity and premorbid intellectual function accounted for variance in insight impairment. As such, we aimed to test whether similar relationships would be observed in earlier life.

METHODS

A retrospective analysis was performed on 1 large sample of participants (n = 171) with a DSM-IV-TR diagnosis of schizophrenia aged 19 to 79 years acquired from 2 studies: (1) a psychosocial intervention trial for older persons with schizophrenia (June 2008 to May 2014) and (2) a diffusion tensor imaging and genetics study of psychosis across the life span (February 2007 to December 2013). We assessed insight into illness using the Positive and Negative Syndrome Scale (PANSS) item G12 and explored its relationship to illness severity (PANSS total modified), premorbid intellectual function (Wechsler Test of Adult Reading [WTAR]), and cognition.

RESULTS

Insight impairment was more severe in later life (≥ 60 years) than in earlier years (t = -3.75, P < .001). Across the whole sample, the variance of impaired insight was explained by PANSS total modified (Exp[B] = 1.070, P < .001) and WTAR scores (Exp[B] = 0.970, P = .028). Although age and cognition were correlated with impaired insight, they did not independently contribute to its variance. However, the relationships between impaired insight and illness severity and between impaired insight and cognition, particularly working memory, were stronger in later life than in earlier life.

CONCLUSIONS

These results suggest an opportunity for intervention may exist with cognitive-enhancing neurostimulation or medications to improve insight into illness in schizophrenia across the life span.

TRIAL REGISTRATION

Original study registered on ClinicalTrials.gov (identifier: NCT00832845).

Cognition and Dopamine D2 Receptor Availability in the Striatum in Older Patients with Schizophrenia

OBJECTIVES

To assess the impact of reducing the dose of antipsychotics on cognition and dopaminergic D₂ receptor availability in the whole striatum, and identify their relationship in patients with schizophrenia aged 50 years or older.

DESIGN

Open-label prospective PET [¹¹C]-raclopride study.

SETTING

A tertiary care center outpatient setting.

PARTICIPANTS

Thirty-seven clinically stable participants with schizophrenia or schizoaffective disorder, aged 50 years or greater, and having been treated with olanzapine or risperidone monotherapy at the same dose for at least 6 months.

INTERVENTION

Gradual reduction in their olanzapine or risperidone daily dose of up to 40%.

MEASUREMENTS

Clinical and cognitive assessments, and [¹¹C]-raclopride PET to determine D₂ receptor availability at baseline and after the dose reduction. Main outcome measures were overall cognition and D₂ receptor availability in whole striatum.

RESULTS

Reducing the antipsychotic dose resulted in an increase in D₂ receptor availability in the whole striatum and an association between D₂ receptor availability and overall cognition despite lack of change in the latter. There was also an association between change in D₂ receptor availability and change in overall cognition.

CONCLUSIONS

Our findings suggest that optimizing D₂ receptor availability by reducing antipsychotic dose allows this system to contribute more significantly to cognitive function in patients with schizophrenia. This uncovered association could be harnessed by cognitive-enhancing interventions.

Threshold of Dopamine D2/3 Receptor Occupancy for Hyperprolactinemia in Older Patients With Schizophrenia

OBJECTIVE

Although hyperprolactinemia carries a long-term risk of morbidity, the threshold of dopamine D2/3 receptor (D2/3R) occupancy for hyperprolactinemia has not been investigated in older patients with schizophrenia. Data were taken from a positron emission tomography (PET) study conducted between August 2007 and August 2015. The present post hoc study included 42 clinically stable outpatients with schizophrenia (DSM-IV) (mean ± SD age = 60.2 ± 6.7 years) taking olanzapine or risperidone. Subjects underwent [¹¹C]-raclopride PET scans to measure D2/3R occupancy before and after reducing their dose of antipsychotic by up to 40%. Blood samples were collected before each PET scan to measure prolactin levels.

METHODS

The relationship between prolactin levels and D2/3R occupancy was examined using stepwise linear regression analyses. The D2/3R occupancy thresholds for hyperprolactinemia were explored using Fisher exact tests.

RESULTS

Prolactin levels decreased following dose reduction (mean ± SD = 24.1 ± 30.2 ng/mL to 17.2 ± 15.1 ng/mL; P < .001). Prolactin levels were associated with female gender (β = .32, P = .006, vs male), antipsychotics (β = .23, P = .02, risperidone vs olanzapine), and D2/3R occupancy (β = .23, P = .04). Those with D2/3R occupancy of 66% or higher were more likely to have hyperprolactinemia than those with D2/3R occupancy lower than 66% (P = .03). Sensitivity, specificity, positive predictive value, and negative predictive value of this threshold were 0.44, 0.81, 0.78, and 0.48, respectively. We identified a D2/3R occupancy threshold for hyperprolactinemia of 66% in older patients with schizophrenia, which is lower than that reported in younger patients (73%) by other researchers.

CONCLUSIONS

Our results suggest a higher sensitivity to antipsychotics in older patients. Prolactin levels could assist in the determination of appropriate antipsychotic dosing to minimize adverse effects.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00716755.

Lack of association between dopaminergic antagonism and negative symptoms in schizophrenia: a positron emission tomography dopamine D2/3 receptor occupancy study

RATIONALE

Several pre-clinical studies suggest that antipsychotic medications cause secondary negative symptoms. However, direct evidence for a relationship among antipsychotic medications, their direct effects on neurotransmitter systems, and negative symptoms in schizophrenia remains controversial.

OBJECTIVE

The objective of this study was to examine the relationship between antipsychotic-related dopamine D_2/3 receptor occupancy and negative symptoms in patients with schizophrenia.

METHODS

Forty-one clinically stable outpatients with schizophrenia participated in this prospective dose reduction positron emission tomography (PET) study. Clinical assessments and [¹¹C]-raclopride PET scans were performed before and after participants underwent gradual dose reduction of their antipsychotic medication by up to 40 % from the baseline dose.

RESULTS

No significant relationship was found between antipsychotic-related dopamine D_2/3 receptor occupancy and negative symptom severity at baseline or follow-up. Similar null findings were found for subdomains of negative symptoms (amotivation and diminished expression). Occupancy was significantly lower following dose reduction; however, negative symptom severity did not change significantly, though a trend toward reduction was noted. Examination of change scores between these two variables revealed no systematic relationship.

CONCLUSIONS

Our cross-sectional and longitudinal results failed to find a significant dose-dependent relationship between severity of negative symptoms and antipsychotic-related dopaminergic antagonism in schizophrenia. These findings argue against the notion that antipsychotics necessarily cause secondary negative symptoms. Our results are also in contrast with the behavioral effects of dopaminergic antagonism routinely reported in pre-clinical investigations, suggesting that the role of this variable in the context of chronic treatment and schizophrenia needs to be re-examined.

Estimating the effect of endogenous dopamine on baseline [(11) C]-(+)-PHNO binding in the human brain

Endogenous dopamine (DA) levels at dopamine D2/3 receptors (D2/3 R) have been quantified in the living human brain using the agonist radiotracer [(11) C]-(+)-PHNO. As an agonist radiotracer, [(11) C]-(+)-PHNO is more sensitive to endogenous DA levels than antagonist radiotracers. We sought to determine the proportion of the variance in baseline [(11) C]-(+)-PHNO binding to D2/3 Rs which can be accounted for by variation in endogenous DA levels. This was done by computing the Pearson's coefficient for the correlation between baseline binding potential (BPND ) and the change in BPND after acute DA depletion, using previously published data. All correlations were inverse, and the proportion of the variance in baseline [(11) C]-(+)-PHNO BPND that can be accounted for by variation in endogenous DA levels across the striatal subregions ranged from 42-59%. These results indicate that lower baseline values of [(11) C]-(+)-PHNO BPND reflect greater stimulation by endogenous DA. To further validate this interpretation, we sought to examine whether these data could be used to estimate the dissociation constant (Kd) of DA at D2/3 R. In line with previous in vitro work, we estimated the in vivo Kd of DA to be around 20 nM. In summary, the agonist radiotracer [(11) C]-(+)-PHNO can detect the impact of endogenous DA levels at D2/3 R in the living human brain from a single baseline scan, and may be more sensitive to this impact than other commonly employed radiotracers.

Dopamine D2/3 Receptor Occupancy Following Dose Reduction Is Predictable With Minimal Plasma Antipsychotic Concentrations: An Open-Label Clinical Trial

BACKGROUND

Population pharmacokinetics can predict antipsychotic blood concentrations at a given time point prior to a dosage change. Those predicted blood concentrations could be used to estimate the corresponding dopamine D2/3 receptors (D2/3R) occupancy by antipsychotics based on the tight relationship between blood and brain pharmacokinetics. However, this 2-step prediction has never been tested.

METHODS

Two blood samples were collected at separate time points from 32 clinically stable outpatients with schizophrenia (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition; mean ± SD age: 60.1 ± 7.3 years) to measure plasma concentrations of olanzapine or risperidone at baseline. Then, subjects underwent a dose reduction of olanzapine or risperidone and completed a [(11)C]-raclopride positron emission tomography scan to measure D2/3R occupancy in the putamen. The plasma concentration at the time of the scan was predicted with the 2 samples based on population pharmacokinetic model, using NONMEM. D2/3R occupancy was then estimated by incorporating the predicted plasma concentration in a hyperbole saturation model. The predicted occupancy was compared to the observed value.

RESULTS

The mean (95% CI) prediction errors for the prediction of D2/3R occupancy were -1.76% (-5.11 to 1.58) for olanzapine and 0.64% (-6.18 to 7.46) for risperidone. The observed and predicted D2/3R occupancy levels were highly correlated (r = 0.67, P = .001 for olanzapine; r = 0.67, P = .02 for risperidone).

CONCLUSIONS

D2/3R occupancy levels can be predicted from blood drug concentrations collected prior to dosage change. Although this 2-step model is subject to a small degree of error, it could be used to select oral doses aimed at achieving optimal D2/3R occupancy on an individual basis.

Switching from 2 antipsychotics to 1 antipsychotic in schizophrenia: a randomized, double-blind, placebo-controlled study

OBJECTIVE

Antipsychotic polypharmacy (APP) is employed routinely, although it remains controversial because robust evidence supporting its efficacy is lacking. In addition, it is associated with increased costs, higher antipsychotic dosing, and greater risk of side effects. Surprisingly, no prospective, randomized, double-blind studies have addressed this issue; the present investigation set out to fill this gap in knowledge.

METHOD

A 12-week, double-blind, randomized, placebo-controlled, single-site study was carried out in individuals with schizophrenia or schizoaffective disorder (DSM-IV) receiving a designated primary antipsychotic plus a secondary antipsychotic, with doses stabilized for each. Individuals were randomly assigned to APP (N = 17), reflecting current treatment, or antipsychotic monotherapy (APM) (N = 18), in which the secondary antipsychotic was discontinued. Assessments occurred weekly during month 1 and every 2 weeks during months 2 and 3; the primary outcome measure was the Brief Psychiatric Rating Scale (BPRS) total score. Other measures included the Clinical Global Impressions (CGI) scale, Simpson-Angus Scale, and Barnes Akathisia Scale. The study was carried out between August 2006 and March 2011.

RESULTS

Withdrawal due to clinical deterioration occurred in 1 individual receiving APP (5.8%) and in 4 individuals in the APM group (22.2%). Overall, however, there was no indication of clinical worsening with APM, as measured using BPRS and CGI scale.

CONCLUSIONS

Almost 80% (n = 14) of individuals with schizophrenia or schizoaffective disorder currently receiving APP could be safely transitioned to APM with no clinical deterioration. For those who do deteriorate, risk appears greatest in the first several months. From another perspective, results also indicate that a minority of individuals benefit from APP, and research focusing on identifying this group may represent the best strategy to curb excessive use of APP.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00493233.

Lack of age-dependent decrease in dopamine D3 receptor availability: a [(11)C]-(+)-PHNO and [(11)C]-raclopride positron emission tomography study

Positron emission tomography with antagonist radiotracers has showed that striatal dopamine D2/3 receptor (D2/3R) availability decreases with age. However, no study has specifically assessed whether D2/3R availability decreases with age in healthy persons as measured with agonist radiotracers. Moreover, it is unknown whether D3R availability changes with age in healthy humans. Thus, we explored the relationship between age and D2/3R availability in healthy humans using the D3 receptor (D3R)-preferential agonist radiotracer [(11)C]-(+)-PHNO (n=72, mean±s.d. age=40±15, range=18 to 73) and the antagonist [(11)C]-Raclopride (n=70, mean±s.d. age =40±14, range=18 to 73) (both, n=33). The contribution of D3R to the [(11)C]-(+)-PHNO signal varies across regions of interest; the substantia nigra and hypothalamus represent D3R-specific regions, the ventral pallidum, globus pallidus, and ventral striatum represent D2/3R-mixed regions, and the caudate and putamen represent D2 receptor (D2R)-specific regions. With [(11)C]-(+)-PHNO, a negative correlation was observed between age and nondisplaceable binding potential (BPND) in the caudate (r(70)=-0.32, P=0.005). No correlations were observed in the other regions. With [(11)C]-Raclopride, negative correlations were observed between age and BPND in the caudate (r(68)=-0.50, P<0.001), putamen (r(68)=-0.41, P<0.001), and ventral striatum (r(68)=-0.43, P<0.001). In conclusion, in contrast with the age-dependent decrease in D2R availability, these findings suggest that D3R availability does not change with age.

Predicting Plasma Olanzapine Concentration Following a Change in Dosage: A Population Pharmacokinetic Study

INTRODUCTION

Due to high inter-individual variability in peripheral pharmacokinetic parameters, dosing of antipsychotics currently relies on clinical trial-and-error, and predicting antipsychotic plasma concentrations before changing a dose has been a challenge.

METHODS

Patients with schizophrenia receiving a stable dose of olanzapine were included. 2 plasma samples were collected at 2 given time points for the measurement of plasma olanzapine concentrations. At least 7 days after a dosage change of olanzapine, a third sample was collected. The plasma concentration of the third sample was predicted in a blinded fashion using a mixed-effects model with NONMEM(®), using the following information: the 2 baseline plasma concentrations, the interval between the last dose and blood draw, and clinical and demographic information.

RESULTS

31 subjects (mean±SD age=56.0±11.6; 19 men) were enrolled. The mean prediction (95% confidence interval) errors were 1.6 (-2.8 to 6.0) ng/mL. A highly significant correlation was observed between the observed and predicted concentrations of the third sample (r=0.91, p<0.001).

DISCUSSION

Plasma olanzapine concentrations following an actual dosage change can be predicted in advance with a high degree of certainty.

Evaluation of Antipsychotic Dose Reduction in Late-Life Schizophrenia: A Prospective Dopamine D2/3 Receptor Occupancy Study

IMPORTANCE

Patients with late-life schizophrenia (LLS) are highly susceptible to antipsychotic adverse effects. Treatment guidelines endorse lower antipsychotic doses. However, the optimal dose of antipsychotics and associated dopamine D2/3 receptor (D2/3R) occupancies remain largely unexplored in patients with LLS.

OBJECTIVE

To evaluate effects of antipsychotic dose reduction on striatal dopamine D2/3R occupancies, clinical variables, and blood pharmacokinetic measures in patients with LLS.

DESIGN, SETTING, AND PARTICIPANTS

An open-label, single-arm prospective study with a 3- to 6-month follow-up period (January 10, 2007, to October 21, 2013) was conducted at an academic tertiary care center with practice for ambulatory care. Participants included 35 outpatients with clinically stable LLS (patients aged ≥ 50 years receiving olanzapine or risperidone monotherapy at the same dose for 6 to 12 months). Follow-up was completed on October 21, 2013, and analysis was conducted from October 22, 2014, to February 2, 2015.

INTERVENTIONS

Carbon 11-labeled raclopride positron emission tomography, clinical measures, and blood pharmacokinetic measures performed before and after gradual dose reduction by up to 40% from the baseline dose and at least 3 months after dose reduction.

MAIN OUTCOMES AND MEASURES

Striatal dopamine D2/3R occupancies with antipsychotics, clinical measures (Positive and Negative Syndrome Scale, Brief Psychiatric Rating Scale, Targeted Inventory on Problems in Schizophrenia, Simpson-Angus Scale, Barnes Rating Scale for Drug-Induced Akathisia, Udvalg for Kliniske Undersøgelser Side Effect Rating Scale), and blood pharmacokinetic measures (prolactin and antipsychotic blood levels).

RESULTS

Dopamine D2/3R occupancy of the entire sample decreased by a mean (SD) of 6.2% (8.2%) following dose reduction (from 70% [12%] to 64% [12%]; P < .001). The lowest D2/3R occupancy associated with clinical stability was 50%. Extrapyramidal symptoms (EPSs) were more likely to occur with D2/3R occupancies higher than 60%: 90.5% (19 of 21) of the participants with baseline EPSs and 76.9% (10 of 13) of the participants with postreduction EPSs had striatal D2/3R occupancies higher than 60%. The baseline D2/3R occupancies were lower in patients with clinical deterioration (n = 5) than in those whose condition remained stable (n = 29) (58% [15%] vs 72% [10%]; P = .03). Following dose reduction, Targeted Inventory on Problems in Schizophrenia score increased (P = .046) and Positive and Negative Syndrome Scale (P = .02), Brief Psychiatric Rating Scale (P = .03), Simpson-Angus Scale (P < .001), Barnes Rating Scale for Drug-Induced Akathisia (P = .03), and Udvalg for Kliniske Undersøgelser Side Effect Rating Scale (P < .001) scores and prolactin (P < .001) and blood antipsychotic (olanzapine, P < .001; risperidone plus the metabolite 9-hydroxyrisperidone, P = .02) levels all decreased.

CONCLUSIONS AND RELEVANCE

Antipsychotic dose reduction is feasible in patients with stable LLS, decreasing adverse effects and improving illness severity measures. The results of the present study suggest a lower therapeutic window of D2/3R occupancy in patients with LLS (50%-60%) than previously reported in younger patients (65%-80%).

Dopamine D₂/₃ receptor availability in the striatum of antipsychotic-free older patients with schizophrenia-A [¹¹C]-raclopride PET study

BACKGROUND

No study has examined dopamine D₂/₃ receptor (D₂/₃R) availability in antipsychotic-free older patients with schizophrenia.

METHODS

We included patients with schizophrenia 50 years or older who were antipsychotic-free for at least 3 months. We compared non-displaceable binding potential (BPND) of [(11)C]-raclopride in the caudate, putamen, ventral striatum, and globus pallidus between patients and age- and sex-matched healthy controls.

RESULTS

Ten patients participated (antipsychotic-naive=4). No differences in BPND were found between patients and controls in any ROIs (F(1, 72)=.42, p=.52).

CONCLUSION

The preliminary results suggest no differences in D₂/₃R availability between antipsychotic-free older patients with schizophrenia and controls.

The VAGUS insight into psychosis scale--self-report and clinician-rated versions

The aim of this study was to develop self-report and clinician-rated versions of an insight scale that would be easy to administer, sensitive to small changes, and inclusive of the core dimensions of clinical insight into psychosis. Ten-item self-report (VAGUS-SR) and five-item clinician-rated (VAGUS-CR) scales were designed to measure the dimensions of insight into psychosis and evaluated in 215 and 140 participants, respectively (www.vagusonline.com). Tests of reliability and validity were performed. Both the VAGUS-SR and VAGUS-CR showed good internal consistency and reliability. They demonstrated good convergent and discriminant validity. Both versions were strongly correlated with one another and with the Schedule for the Assessment of Insight and Birchwood Insight Scale. Exploratory factor analyses identified three possible latent components of insight. The VAGUS-CR and VAGUS-SR are valid, reliable and easy to administer. They are build on previous insight scales with separate clinician-rated and self-report versions. The VAGUS-SR exhibited a multidimensional factor structure. Using a 10-point Likert scale for each item, the VAGUS has the capacity to detect small, temporally sensitive changes in insight, which is essential for intervention studies with neurostimulation or rapidly acting medications.

Impaired insight into illness and cognitive insight in schizophrenia spectrum disorders: resting state functional connectivity

BACKGROUND

Impaired insight into illness (clinical insight) in schizophrenia has negative effects on treatment adherence and clinical outcomes. Schizophrenia is described as a disorder of disrupted brain connectivity. In line with this concept, resting state networks (RSNs) appear differentially affected in persons with schizophrenia. Therefore, impaired clinical, or the related construct of cognitive insight (which posits that impaired clinical insight is a function of metacognitive deficits), may reflect alterations in RSN functional connectivity (fc). Based on our previous research, which showed that impaired insight into illness was associated with increased left hemisphere volume relative to right, we hypothesized that impaired clinical insight would be associated with increased connectivity in the DMN with specific left hemisphere brain regions.

METHODS

Resting state MRI scans were acquired for participants with schizophrenia or schizoaffective disorder (n=20). Seed-to-voxel and ROI-to-ROI fc analyses were performed using the CONN-fMRI fc toolbox v13 for established RSNs. Clinical and cognitive insight were measured with the Schedule for the Assessment of Insight-Expanded Version and Beck Cognitive Insight Scale, respectively, and included as the regressors in fc analyses.

RESULTS

As hypothesized, impaired clinical insight was associated with increased connectivity in the default mode network (DMN) with the left angular gyrus, and also in the self-referential network (SRN) with the left insula. Cognitive insight was associated with increased connectivity in the dorsal attention network (DAN) with the right inferior frontal cortex (IFC) and left anterior cingulate cortex (ACC).

CONCLUSION

Increased connectivity in DMN and SRN with the left angular gyrus and insula, respectively, may represent neural correlates of impaired clinical insight in schizophrenia spectrum disorders, and is consistent with the literature attributing impaired insight to left hemisphere dominance. Increased connectivity in the DAN with the IFC and ACC in relation to cognitive insight may facilitate enhanced mental flexibility in this sample.

Illness denial in schizophrenia spectrum disorders: a function of left hemisphere dominance

Impaired illness awareness or anosognosia is a common, but poorly understood feature of schizophrenia that contributes to medication nonadherence and poor treatment outcomes. Here we present a functional imaging study to measure brain activity at the moment of illness denial. To accomplish this, participants with schizophrenia (n = 18) with varying degrees of illness awareness were confronted with their illness beliefs while undergoing functional MRI. To link structure with function, we explored the relationships among impaired illness awareness and brain activity during the illness denial task with cortical thickness. Impaired illness awareness was associated with increased brain activity in the left temporoparieto-occipital junction (TPO) and left medial prefrontal cortex (mPFC) at the moment of illness denial. Brain activity in the left mPFC appeared to be a function of participants' degree of self-reflectiveness, while the activity in the left TPO was associated with cortical thinning in this region and more specific to illness denial. Participants with impaired illness awareness had slower response times to illness related stimuli than those with good illness awareness. Increased left hemisphere brain activity in association with illness denial is consistent with the literature in other neuropsychiatric conditions attributing anosognosia or impaired illness awareness to left hemisphere dominance. The TPO and mPFC may represent putative targets for noninvasive treatment interventions, such as transcranial magnetic or direct current stimulation.

Insight into illness in late-life schizophrenia: a function of illness severity and premorbid intellectual function

Impaired insight into illness is a common but poorly understood phenomenon in schizophrenia. Several studies in midlife adults with schizophrenia have reported an association between impaired insight and illness severity, executive dysfunction, premorbid intellectual function, and to a lesser degree attention. Aging is associated with a decline in attention and executive function. Thus, the relationship between cognition and insight is expected to differ between younger and older adults with schizophrenia. This study assessed this relationship among 50 patients with schizophrenia 60 years and older. Insight was explained by illness severity (16.2% of the variance) and premorbid intellectual function (23.9% of the variance), but not by attention or executive function. Our findings suggest that the predictors of insight in schizophrenia differ early and later in life. In particular, insight's association with attention and executive function observed in younger patients is attenuated by age-related changes in cognition. In contrast, premorbid intellectual function continues to be a strong predictor of insight in late life, which highlights the need to better understand and enhance cognitive function early in the course of schizophrenia.

Hyperprolactinemia and estimated dopamine D2 receptor occupancy in patients with schizophrenia: analysis of the CATIE data

BACKGROUND

Large-scale data are still lacking on the relationship between serum prolactin concentration and dopamine D2 receptor occupancy in patients with schizophrenia treated with antipsychotics.

METHODS

The dataset from 481 subjects (risperidone, N = 172, olanzapine, N = 211, and ziprasidone, N = 98) who participated in Phase 1 of the Clinical Antipsychotic Trials in Intervention Effectiveness (CATIE) was used in the present analysis. Dopamine D2 receptor occupancy levels on the day of the measurement of serum prolactin level were estimated from plasma antipsychotic concentrations. A multivariate general linear model was used to examine effects of clinical and demographic characteristics, including estimated D2 occupancy levels, on serum prolactin concentrations. Individual subjects were divided into two groups, stratified by the presence of hyperprolactinemia. To evaluate the performance of this binary classification, sensitivity, specificity, and accuracy of consecutive cut-off points in the D2 occupancy were calculated.

RESULTS

The multivariate general linear model revealed that estimated D2 occupancy levels had significant effects on serum prolactin concentrations while any other variables failed to show significant effects. The cut-off point associated with 0.5 or greater, in both sensitivity and specificity with the greatest accuracy, was 73% (sensitivity, 0.58; specificity, 0.68; accuracy = 0.64) (68-70% for risperidone, 77% for olanzapine, and 55% for ziprasidone.).

CONCLUSION

The threshold for hyperprolactinemia in D2 occupancy may lie somewhat on a lower side of the established therapeutic window with antipsychotics (i.e. 65-80%). This finding highlights the need for the use of the lowest possible dose to avoid this hormonal side effect in the treatment of schizophrenia.

Dopamine D2 receptor occupancy and cognition in schizophrenia: analysis of the CATIE data

INTRODUCTION

Antipsychotic drugs exert antipsychotic effects by blocking dopamine D2 receptors in the treatment of schizophrenia. However, effects of D2 receptor blockade on neurocognitive function still remain to be elucidated. The objective of this analysis was to evaluate impacts of estimated dopamine D2 receptor occupancy with antipsychotic drugs on several domains of neurocognitive function in patients with schizophrenia in the Clinical Antipsychotic Trials in Intervention Effectiveness (CATIE) trial.

METHODS

The dataset from the CATIE trial was used in the present analysis. Data were extracted from 410 subjects who were treated with risperidone, olanzapine, or ziprasidone, received assessments for neurocognitive functions (verbal memory, vigilance, processing speed, reasoning, and working memory) and psychopathology, and provided plasma samples for the measurement of plasma antipsychotic concentrations. D2 receptor occupancy levels on the day of neurocognitive assessment were estimated from plasma antipsychotic concentrations, using population pharmacokinetic analysis and our recently developed model. A multivariate general linear model was used to examine effects of clinical and demographic characteristics, including estimated D2 occupancy levels, on neurocognitive functions.

RESULTS

D2 occupancy levels showed significant associations with the vigilance and the summary scores. Neurocognitive functions, including vigilance, were especially impaired in subjects who showed D2 receptor occupancy level of >77%.

DISCUSSION

These findings suggest a nonlinear relationship between prescribed antipsychotic doses and overall neurocognitive function and vigilance. This study shows that D2 occupancy above approximately 80% not only increases the risk for extrapyramidal side effects as consistently reported in the literature but also increases the risk for cognitive impairment.

Predicting hospital length of stay for geriatric patients with mood disorders

OBJECTIVE

To determine predictors of hospital length of stay (LOS) for adult and geriatric patients with mood disorders admitted to inpatient psychiatric beds.

METHOD

Admission and discharge data from a large urban mental health centre, from 2005 to 2010 inclusive, were retrospectively analyzed. Using the Resident Assessment Instrument-Mental Health, an assessment that is used to collect demographic and clinical information within 72 hours of hospital admission, 199 geriatric mood disorder admissions were compared with 570 adult mood disorder admissions. Predictors of hospital LOS were determined using a series of general linear models.

RESULTS

Living alone, number of recent psychiatric admissions, involuntary admission, and close or constant observation level predict longer hospital LOS in geriatric, but not in adult mood disorder, patients. Conversely, pain on admission predicts shorter hospital LOS in geriatric, but not among adult, mood disorder patients. Predictors of longer hospital LOS, irrespective of admission group (adult, compared with geriatric), include incapacity, negative symptoms, and increased dependence for instrumental activities of daily living.

CONCLUSIONS

Addressing these predictive factors early on during admission and in the community may result in shorter hospital LOS and more optimal use of resources.

Therapeutic Window for Striatal Dopamine D2/3 Receptor Occupancy in Older Patients With Schizophrenia: A Pilot PET Study

OBJECTIVE:: In younger patients with schizophrenia, positron emission tomography (PET) studies have identified a therapeutic window of striatal dopamine D2/3 receptor occupancy of 65%-80%. This type of empirical information is not available in late life. Our primary aim was to assess the effect of changes in D2/3 relative receptor occupancy (RRO) on clinical outcomes in this population. DESIGN:: Open-label intervention. SETTING:: Centre for Addiction and Mental Health, Toronto. PARTICIPANTS:: Subjects with schizophrenia age 50 years or more who were clinically stable and previously maintained on oral risperidone for more than 6 months. INTERVENTION:: A dose reduction of risperidone of up to 40%, followed by a 3-month follow-up. MEASUREMENTS:: Dopamine D2/3 RRO in dorsal putamen was assessed, using the region of interest analysis of [C]raclopride PET scans, before and after the dose reduction. Clinical assessments included the Positive and Negative Syndrome Scale and the Simpson-Angus Scale. RESULTS:: Nine subjects (mean ± SD age: 58 ± 7 years; mean ± SD baseline risperidone dose: 3.4 ± 1.6 mg/day) participated in the study. Extrapyramidal symptoms (EPS) were present in six subjects and were associated with 70% or more D2/3 RRO in the putamen (range: 70%-87%). Following the dose reduction, EPS resolved in five subjects. Two subjects experienced a clinical worsening at 52% and at less than 50% D2/3 RRO. CONCLUSION:: EPS diminished less than 70% D2/3 RRO, which suggests a lower therapeutic window for older patients with schizophrenia than that for younger patients. Although these findings have to be replicated in a larger sample, they have important implications for future drug development and clinical guidelines in late-life schizophrenia.

Cholinergic pathways and cognition in patients with schizophrenia: a pilot study

BACKGROUND

Cognitive deficits are core features in schizophrenia. Disruption in cholinergic neurotransmission has been associated with executive dysfunction in animals and humans. The objective of this study was to evaluate the impact of compromised cholinergic pathways on executive versus non-executive cognitive functions of patients with schizophrenia.

METHODS

62 patients with schizophrenia and 62 age- and sex-matched non-psychiatric control subjects ("controls") were assessed and compared using: clinical measures, cognitive measures of global cognition, executive function, and memory; and an MRI-based visual rating scale that assesses damage strategically localized within the cholinergic pathways.

RESULTS

11 of the 62 patients with schizophrenia (17.7%) and 6 of the 62 controls (9.7%) had compromised cholinergic pathways. These proportions were not statistically significant. Patients and controls with compromised cholinergic pathways were more impaired on measures related to executive function than patients or controls without compromised pathways.

CONCLUSIONS

Patients with schizophrenia have worse executive function than controls. Compromised cholinergic pathways appear to worsen the executive dysfunction observed in schizophrenia. If these preliminary findings are replicated, they could lead to the identification of a subgroup of patients with schizophrenia who could specifically benefit from interventions enhancing cholinergic neurotransmission.

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.

Defining treatment-resistant schizophrenia and response to antipsychotics: a review and recommendation

Treatment-resistant schizophrenia (TRS) has been defined mainly by severity of (positive) symptoms and response to antipsychotics derived from a relative change in the representative scales (most frequently ≥ 20% decrease in the Positive and Negative Syndrome Scale: PANSS), but these definitions have not necessarily been consistent. Integrating past evidence and real-world practicability, we propose that TRS be defined by at least two failed adequate trials with different antipsychotics (at chlorpromazine-equivalent doses of ≥ 600mg/day for ≥ 6 consecutive weeks) that could be retrospective or preferably include prospective failure to respond to one or more antipsychotic trials. In addition, our proposed criteria require both a score of ≥ 4 on the Clinical Global Impression (CGI)-Severity and a score of ≤ 49 on the Functional Assessment for Comprehensive Treatment of Schizophrenia (FACT-Sz) or ≤ 50 on the Global Assessment of Functioning (GAF) scales to define TRS. Once TRS is established, we propose that subsequent treatment response be defined based on a CGI-Change score of ≤ 2, a ≥ 20% decrease on the total PANSS or Brief Psychiatric Rating Scale (BPRS) scores, and an increase of ≥ 20 points on the FACT-Sz or GAF. While these suggestions provide a pragmatic framework for TRS classification, they need to be tested in future trials.

Effects of aging on 5-HT(2A) R binding: a HRRT PET study with and without partial volume corrections

OBJECTIVE

We explored whether prior findings of reduction in serotonin 2A receptor (5-HT(2A) R) binding with age could be replicated and whether high resolution research tomography (HRRT) for positron emission tomography could compensate for partial volume effects in the presence of age-related brain atrophy, which has been a traditional concern for radioligand PET studies in the elderly.

METHODS

We derived 5-HT(2A) R nondisplaceable binding potentials (BP(ND) ) in frontal, temporal, anterior-cingulate, insula, caudate and putamen volumes of interest (VOIs) for 28 healthy subjects (mean ± SD age = 43.9 ± 17.0 years, range: 19-78 years) using HRRT. Partial volume correction (PVC) was performed in the VOI analysis.

RESULTS

The 5-HT(2A) R BP(ND) s decreased with age, a relationship best described by an exponential-decay regression. The BP(ND) s were found to be consistent before and after PVC, with an intra-class correlation coefficient of 0.84 and 95% confidence interval = 0.78-0.88.

CONCLUSIONS

These new findings update current knowledge, in that the aging process is not always uniform across the life span and suggest that PVC may not be necessary with HRRT in healthy subjects.

Treatment resistant schizophrenia and response to antipsychotics: a review

BACKGROUND

There remains a lack of agreement regarding criteria for treatment-resistant schizophrenia (TRS) and definition of response.

METHOD

A literature search was conducted to identify clinical studies of antipsychotics in TRS using PubMed, EMBASE and PsycINFO (last search 31 July 2011). Psychopharmacological studies with the number of participants of ≥ 40 were evaluated in terms of definitions for TRS and subsequent treatment response.

RESULTS

Thirty-three studies of antipsychotics in TRS were reviewed. TRS has been defined mainly by severity in symptoms. Many studies based TRS with at least 2 failed adequate antipsychotic trials (at chlorpromazine equivalent doses of ≥ 1000 mg/day for ≥ 6 weeks), but some studies adopted prospective treatment arm to be certain of sample refractoriness. Treatment response has been defined by a relative change in the representative scales (most commonly ≥ 20% decrease in the Positive and Negative Syndrome Scale), but it sometimes included the absolute criteria such as post-treatment score of ≤ 35 in the Brief Psychiatric Rating Scale or Clinical Global Impression-severity score of ≤ 3 (mild or less severe). Social functioning has not been a primary outcome measure in past pivotal trials, and other important domains of the illness such as cognition and subjective perspectives have not been incorporated into definitions of treatment resistance or response. However, adopting various assessment scales can be time-consuming and complicated, with an additional possibility of disagreement among raters.

CONCLUSION

Defining outcomes in schizophrenia is a challenging task. It is imperative that the field agrees on how this population is better defined and what constitutes treatment response.

Impact of feedback from pharmacists in reducing antipsychotic polypharmacy in schizophrenia

The objective was to examine effects of active interventions on physician's prescribing of antipsychotic polypharmacy. Prescriptions for patients with schizophrenia at the Centre for Addiction and Mental Health, Canada were collected in 2006 (n = 648) and 2008 (n = 778). During the intervening period, a pharmacist monitored prescriptions with antipsychotic polypharmacy and contacted corresponding prescribers to provide education on risks of polypharmacy. Moreover, educational sessions on polypharmacy were presented to inpatient and outpatient teams. A three-fold decrease in the prevalence of antipsychotic polypharmacy was observed between 2006 (18.3%) and 2008 (6.6%). Thus, active monitoring of prescriptions with educational interventions could reduce antipsychotic polypharmacy.

Time course of improvement with antipsychotic medication in treatment-resistant schizophrenia

BACKGROUND

Improvements are greatest in the earlier weeks of antipsychotic treatment of patients with non-resistant schizophrenia.

AIMS

To address the early time-line for improvement with antipsychotics in treatment-resistant schizophrenia.

METHOD

Randomised double-blind trials of antipsychotic medication in adult patients with treatment-resistant schizophrenia were investigated (last search June 2010). A series of metaregression analyses were carried out to examine the effect of time on the average item scores in the Positive and Negative Syndrome Scale (PANSS) or Brief Psychiatric Rating Scale (BPRS) at three or more distinct time points within the first 6 weeks of treatment.

RESULTS

Study duration varied from 4 weeks to 1 year and the definitions of treatment resistance as well as of treatment response were not necessarily consistent across 19 identified studies, resulting in highly variable rates of response (0–76%).The mean standardised baseline item score in the PANSS or BPRS was 3.4 (s.e. = 0.06) in the five studies included in the meta-regression analysis, with the average baseline Clinical Global Impression – Severity score being 5.2 (marked illness). For the pooled population treated with a range of antipsychotics (n = 1019), significant reductions in the mean item scores occurred during the first 4 weeks; improvements observed in later weeks were smaller and non-significant. In contrast, weekly improvement with clozapine was significant throughout (n = 356).

CONCLUSIONS

Our findings provide preliminary evidence that the majority of improvement with antipsychotics may occur relatively early.More consistent improvements with clozapine may be associated with a gradual titration. To further elucidate response patterns, future studies are needed to provide data over regular intervals during earlier stages of treatment.

Dopamine D2 receptor occupancy and clinical effects: a systematic review and pooled analysis

Positron emission tomography (PET) studies proposed a therapeutic window of D2 receptor occupancy (65%-80%) of antipsychotics for the treatment of schizophrenia in young adults. However, this conclusion has been drawn from clinical PET studies using small sample sizes (<20). Prospective PET studies that measured D2 occupancy levels and assessed extrapyramidal side effects (EPS) and/or treatment response induced by antipsychotics (excluding partial agonists) were identified, using MEDLINE and EMBASE (last search: March 2010). Individual subjects were divided into 2 groups based on EPS status (ie, presence or lack of newly emergent EPS) and treatment response (ie, a ≥ 25% or ≥ 50% reduction in the Positive and Negative Syndrome Scale or Brief Psychiatric Rating Scale). To evaluate the performance of this binary classification, sensitivity, specificity, and accuracy of consecutive cutoff points in the D2 occupancy were calculated: Accuracy = (True Positive + True Negative) / Total N. Twelve studies, including a total of 82 subjects, were included in our analyses. The cutoff points associated with 0.5 or greater in both sensitivity and specificity with the greatest accuracy were 77% to 78% for EPS, 60% for a 25% or greater symptom reduction, and 72% for a 50% or greater symptom reduction. These findings support the presence of a therapeutic window of 60% to 78% D2 occupancy of antipsychotics in young adults with schizophrenia and may suggest the presence of a continuum of effectiveness with increasing occupancy within this therapeutic window.

Low dose vs standard dose of antipsychotics for relapse prevention in schizophrenia: meta-analysis

BACKGROUND

It remains unknown as to whether the antipsychotic dose needed for the acute-phase treatment of schizophrenia is also necessary for relapse prevention.

AIM

To compare the efficacy between standard dose [(World Health Organization daily defined dose (DDD)] vs low dose (≥50% to <1 DDD) or very low dose (<50% DDD) for relapse prevention in schizophrenia.

DATA SOURCE

Double-blind, randomized, controlled trials with a follow-up duration of ≥24 weeks, including ≥2 dosage groups of the same antipsychotic drug for relapse prevention in schizophrenia, were searched using MEDLINE, the Cochrane Central Register of Controlled Trials, and EMBASE (last search: August 2009).

DATA EXTRACTION

Data on overall treatment failure, hospitalization, relapse, and dropouts due to side effects were extracted and combined in a meta-analysis.

DATA SYNTHESIS

Thirteen studies with 1395 subjects were included in this meta-analysis. Compared with the standard-dose treatment, the low-dose therapy did not show any statistically significant difference in overall treatment failure or hospitalization, while the standard dose showed a trend-level (P = .05) superiority in risk of relapse. The very low-dose group was inferior to the standard-dose group in all efficacy parameters. No significant difference was found in the rate of dropouts due to side effects between either standard dose vs low dose or very low dose.

CONCLUSIONS

Although antipsychotic treatment with ≥50% to <1 DDD may be as effective as standard-dose therapy, there are insufficient clinical trial data to draw firm conclusions on standard- vs low-dose maintenance antipsychotic therapy for schizophrenia.

Towards the development of new subtype-specific muscarinic receptor radiopharmaceuticals — Radiosynthesis and ex vivo biodistribution of [18F]3-(4-(2-(2-(2-fluoroethoxy)ethoxy)ethylthio)-1,2,5-thiadiazol-3-yl)-1-methyl-1,2,5,6-tetrahydropyridine

Muscarinic receptors have been implicated in neurological disorders including Alzheimer’s disease, Parkinson’s disease, and schizophrenia. Nineteen derivatives of thiadiazolyltetrahydropyridine (TZTP), a core that has previously shown high affinities towards muscarinic receptor subtypes, were synthesized and evaluated via in vitro binding assays. The title compound, a fluoro-polyethyleneglycol analog of TZTP (4c), was subsequently labelled with fluorine-18. Fluorine-18-labelled 4c was produced, via an automated synthesis, in an average radiochemical yield of 36% (uncorrected for decay), with high radiochemical purity (>99%) and high specific activity (326 GBq/µmol; end-of-bombardment), within 40 min (n = 3). Ex vivo biodistribution studies following tail-vein injection of [18F]4c in conscious rats displayed sufficient brain uptake (0.4%–0.7% injected dose / gram of wet tissue in all brain regions at 5 min post injection); however, there were substantial polar metabolites present in the brain, thereby precluding future use of [18F]4c for imaging in the central nervous system.

Are antipsychotic prescribing patterns different in older and younger adults?: a survey of 1357 psychiatric inpatients in Toronto

OBJECTIVE

To compare antipsychotic prescribing patterns in younger (aged 59 years or younger) and older (aged 60 years or older) patients with psychotic or mood disorders.

METHOD

Pharmacy records of all patients discharged from the Centre for Addiction and Mental Health over a 21-month period were reviewed. A total of 1357 patients who were prescribed an antipsychotic at the time of their discharge were included in the analysis (956 with a primary psychotic disorder and 401 with a primary mood disorder). World Health Organization-defined daily doses were used as the standardized dosing unit.

RESULTS

Both in patients with a primary psychotic disorder and in patients with a primary mood disorder, the prescribing patterns were similar in older and younger patients, with no statistical difference in the proportions receiving first-generation antipsychotics, second-generation antipsychotics (SGAs), multiple antipsychotics, or long-acting (depot) antipsychotics. Overall, the mean daily antipsychotic doses were lower only in the older group of patients with a primary mood disorder. However, the mean dose of SGAs was about 30% lower in older patients in both diagnostic groups. Regardless of age, patients with a mood disorder were prescribed lower doses of antipsychotics than those with a psychotic disorder.

CONCLUSIONS

Our data suggest that older patients are prescribed lower antipsychotic dosages primarily when using SGAs. This finding emphasizes the need for dose-finding studies assessing both the efficacy and the safety of antipsychotics in older patients with a psychotic or mood disorder.

Predicting age-specific dosing of antipsychotics

Antipsychotic medications are the standard of care for both acute and maintenance treatment of schizophrenia, the latter requiring an indefinite treatment across a patient's life span. However, dosing and tolerability of antipsychotics have been studied primarily in younger patients, and very limited data are available for age- and phase-specific dosing. This leaves the clinician with no guidance on dose adjustment as patients grow older-an issue of critical importance, especially in light of recent concerns about increased morbidity and mortality associated with antipsychotics.

Dosing of antipsychotics in schizophrenia across the life-spectrum

Age effects on dosing of antipsychotics in schizophrenia and mechanisms underlying those effects have not been well understood. The objective of this article is to review the literature regarding effects of age on antipsychotic dosing in schizophrenia and potential mechanisms underlying the age-related antipsychotic sensitivity. According to prescription surveys, age appears to have biphasic effects on prescribed antipsychotic dose. The dose increased with age through the third decade, subsequently plateaued, and decreased after the fifth decade. The first half of this inverted U-shaped relationship may be attributable to a deterioration process in the early phase of schizophrenia and the contribution of 'tachyphylaxis' of antipsychotics on the dopaminergic system. The following age-related decline in prescribed dose is likely associated with physiological aging. Recent data suggest that this increased antipsychotic sensitivity with age comes from age-related functional decline in the dopaminergic system, including endogenous dopamine level and dopamine receptor density. Although the evidence on potential mechanisms underlying age effects on antipsychotic dosing is still limited, alterations in the dopaminergic system due to aging and chronic exposure to this drug may contribute to the inverted U-shaped relationship between dose and age. This age-related antipsychotic sensitivity highlights the importance of finding the lowest possible effective dose of antipsychotic drugs as patients age to enhance therapeutic effects as well as minimize their side effects.

Test-retest variability of high resolution positron emission tomography (PET) imaging of cortical serotonin (5HT2A) receptors in older, healthy adults

Background

Position emission tomography (PET) imaging using [¹⁸F]-setoperone to quantify cortical 5-HT_2A receptors has the potential to inform pharmacological treatments for geriatric depression and dementia. Prior reports indicate a significant normal aging effect on serotonin 5HT_2A receptor (5HT_2AR) binding potential. The purpose of this study was to assess the test-retest variability of [¹⁸F]-setoperone PET with a high resolution scanner (HRRT) for measuring 5HT_2AR availability in subjects greater than 60 years old. Methods: Six healthy subjects (age range = 65–78 years) completed two [¹⁸F]-setoperone PET scans on two separate occasions 5–16 weeks apart.

Results

The average difference in the binding potential (BP_ND) as measured on the two occasions in the frontal and temporal cortical regions ranged between 2 and 12%, with the lowest intraclass correlation coefficient in anterior cingulate regions.

Conclusion

We conclude that the test-retest variability of [¹⁸F]-setoperone PET in elderly subjects is comparable to that of [¹⁸F]-setoperone and other 5HT_2AR radiotracers in younger subject samples.

Benzodiazepine and antidepressant use in elderly patients with anxiety disorders: a survey of 796 outpatients in Japan

Since the literature on benzodiazepine use in elderly patients with anxiety disorders is limited, a large cross-sectional review of psychotropic prescriptions in 796 patients with neurotic disorders (ICD-10) (age range=11-91 years) was conducted across 30 sites in Japan. Use of benzodiazepine-derivative anxiolytics was approximately 70% in all decades without a group difference. The proportion of subjects who received prescriptions for benzodiazepine-derivative anxiolytics in the absence of antidepressants was higher in older age groups (e.g., 27.7% and 43.2% in the third and sixth decades, respectively). On the other hand, antidepressants were less frequently prescribed in older age groups (e.g., 59.8% and 41.5% in the third and sixth decades, respectively). The very high use of anxiolytics in the elderly, especially in the absence of concomitant antidepressant use, is a cause for concern since they are not a preferred long-term treatment strategy given their adverse effects in the elderly.

Long-term stability of measuring D(2) receptors in schizophrenia patients treated with antipsychotics

BACKGROUND

While antipsychotic-free schizophrenia patients showed a high degree of within-subject variability in dopamine D(2) receptor density over 6-24 months, no study has examined the long-term stability of D(2) receptor measures in medicated patients.

METHODS

Four schizophrenia patients receiving a stable dose of risperidone underwent [(11)C]raclopride positron emission tomography scans on two occasions 5-14 months apart.

RESULTS

Plasma risperidone levels were found to be consistent between scans, and consistencies of nondisplaceable D(2) binding potential and D(2) occupancy were good.

CONCLUSIONS

The finding supports the validity of quantification of D(2) receptor binding in longitudinal PET studies of medicated patients with schizophrenia.

Survey of benzodiazepine and antidepressant use in outpatients with mood disorders in Japan

Data on benzodiazepine use in mood disorders are still limited, especially among seniors. A cross-sectional review of psychotropic prescriptions in 948 outpatients with mood disorders (405 male; mean +/- SD age, 52 +/- 17 years; age range, 16- 91 years) was conducted in Japan. The use of benzodiazepine-derivative anxiolytics was approximately 60% in all decades, including older patients, without a group difference. The frequent use of benzodiazepines is a cause for concern because they are not preferred treatment, given their well-known adverse effects especially in the elderly.

Increased antipsychotic sensitivity in elderly patients: evidence and mechanisms

OBJECTIVE

The primary objective of this article is to review the literature regarding clinical effects, pharmacokinetics, and pharmacodynamics of antipsychotics in older people and to examine potential mechanisms underlying the age-related antipsychotic sensitivity.

DATA SOURCES

Data for this review were identified by searches of PubMed (1950-2007) and references from relevant articles and books. Search terms included antipsychotic, neuroleptic, elderly, aging, pharmacokinetics, pharmacodynamics, and dopamine, and only articles written in English or Japanese were consulted.

DATA SELECTION

Studies, reviews, and books pertaining to the clinical effects, pharmacokinetics, and pharmacodynamics with regard to the use of antipsychotics in older patients were selected.

DATA SYNTHESIS

The prevailing practices and clinical guidelines suggest that elderly patients can obtain therapeutic benefits at a lower dose and experience adverse effects from antipsychotics more often than younger patients, although there are still few trials that have directly compared elderly patients with the young. The literature suggests an age-related increase in brain access of drugs and demonstrates a decrease with age in the principal components in the dopaminergic system, including endogenous dopamine level and dopamine receptor density.

CONCLUSIONS

While clinicians conclusively hold that patients become more sensitive to antipsychotics as they become older, this proposition has only modest empirical support and warrants further investigation. Age-related functional decline in the dopaminergic system predicts lower antipsychotic doses for older patients. We propose a hierarchical series of testable hypotheses to address the relative contribution of age-related pharmacokinetic and pharmacodynamic changes to antipsychotic drug sensitivity.

Monthly administration of long-acting injectable risperidone and striatal dopamine D2 receptor occupancy for the management of schizophrenia

OBJECTIVE

Long-acting risperidone administered intramuscularly biweekly is approved for the management of schizophrenia. However, dosing of long-acting antipsychotics is frequently extended in clinical practice, and a recent clinical trial has lent support to monthly dosing of long-acting risperidone. The objective of this positron emission tomography (PET) study was to examine the striatal dopamine D(2) binding of long-acting risperidone administered intramuscularly once a month.

METHOD

Following at least 3 maintenance monthly injections of 50 mg long-acting risper-idone, 7 patients with a DSM-IV diagnosis of schizophrenia or schizoaffective disorder under-went PET using [(11)C]raclopride to measure D(2) binding potential within 4 days of the next scheduled injection. Data were collected from May to October 2003. This PET study was part of a larger 52-week clinical study wherein individuals received long-acting risperidone once monthly over a 1-year interval. One-year follow-up data were obtained from the 52-week parent investigation.

RESULTS

The mean +/- SD D(2) receptor occupancy was 56% +/- 24% (range, 29%-82%). Of note, there were 4 subjects with less than 60% D(2) occupancy, none of whom relapsed over the course of the 1-year follow-up. The mean +/- SD total plasma level of risperidone plus 9-hydroxyrisperidone was 16.6 +/- 12.3 ng/mL (range, 5.7-40.8).

CONCLUSION

As with plasma levels, there was considerable variability in D(2) occupancy levels for individuals receiving long-acting risperidone. This work suggests a possibility that sustained D(2) occupancy at or above the accepted threshold with acute clinical response may not be necessary to maintain response, a hypothesis with important clinical implications as we consider antipsychotic dosing and future antipsychotic development.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00236353.

Quetiapine extended-release versus immediate-release formulation: a positron emission tomography study

OBJECTIVE

The pharmacokinetic and pharmacodynamic profile of the immediate-release (IR) formulation of quetiapine is characterized by a rapid peak in plasma level and striatal dopamine D(2) receptor occupancy, followed by a rapid decrease to baseline levels, necessitating the use of twice-daily dosing. An extended-release (XR) formulation of quetiapine is currently being developed to achieve similar efficacy using a once-daily dosing regimen. We compared the central D(2) receptor binding between the IR and XR formulations.

METHOD

In this open-label, crossover positron emission tomography study using [(11)C]-raclopride, we compared the central D(2) receptor binding potential at expected peak and trough plasma levels using equivalent daily doses of the IR and XR formulations (300, 600, and 800 mg/day) in 12 subjects. Data were collected from April 2002 to May 2003.

RESULTS

The mean plasma level of quetiapine at trough was significantly lower than that at peak for all dose groups of both formulations except for IR 300 and 800 mg (all p values < .05), while the mean plasma level did not differ significantly between formulations at trough and peak. The mean occupancy at peak was significantly higher than that at trough for all dose groups other than IR 800 mg/day (all p values < .05) and did not differ significantly between formulations at trough and peak.

CONCLUSION

Once-daily dosing of the XR formulation gives peak and trough plasma levels and central D(2) receptor occupancy comparable to twice-daily dosing of the IR formulation. These data should be considered while determining equivalent doses, as well as switching strategies.

Managing suicidality in schizophrenia

OBJECTIVE

The primary objective of this review article is to provide a coherent, systematic synthesis of the literature on the management of suicidality in schizophrenia that is relevant to the front-line clinician.

METHOD

Literature searches were conducted on MEDLINE (1996 to 2007) and PubMed (1993 to 2007), using the key words "schizophrenia" and "suicide," as well as references from the resulting articles. I used my own clinical experience to create fictional case examples to illustrate the applicability of the literature discussed in this paper.

RESULTS

Suicidality in schizophrenia is high, and early detection relies on the appreciation and evaluation of the clinical manifestations of depression, despair, and hopelessness, as well as on the nature and severity of the psychotic experience itself, particularly in recent-onset patients with higher cognitive function and educational background. Clinical management includes ensuring immediate safety, the use of psychosocial techniques to address depression and psychosocial stressors, targeted pharmacotherapy for depression and psychosis, and adequate discharge planning. Clozapine is the only antipsychotic with good evidence for efficacy in decreasing suicidal behaviour in schizophrenia.

CONCLUSIONS

The optimal management of suicidality in schizophrenia involves the incorporation of traditional bedside clinical skills, selection of psychosocial modalities based on individual needs, and selective pharmacotherapy directed primarily at psychotic and depressive symptoms.

Adverse subjective experience with antipsychotics and its relationship to striatal and extrastriatal D2 receptors: a PET study in schizophrenia

OBJECTIVES

Antipsychotic medications improve psychosis but often induce a state of dysphoria in patients. Blockade of the dopamine D(2) receptors, which is thought to mediate their efficacy, has also been implicated in producing this adverse subjective experience. The authors present the first double-blind controlled study to examine the relationship between striatal and extrastriatal dopamine D(2) receptor binding potential and occupancy values and adverse subjective experience.

METHOD

Patients with recent-onset psychosis (N=12) were randomly assigned to low or high doses of olanzapine or risperidone. Subjective experiences, motor side effects, and striatal and extrastriatal dopamine D(2) receptors (determined with [(11)C]raclopride and [(11)C]FLB 457 PET scans, respectively) were evaluated after 2 weeks of continuous antipsychotic treatment.

RESULTS

Higher dopamine D(2) receptor occupancy and binding potentials in the striatal (dorsal and ventral), temporal, and insular regions were associated with subjective experience. The finding was confirmed with two convergent methods of analysis (region-of-interest and voxel-based statistics), and the same relationship was observed using two different dopamine receptor measures (observed binding potential values and age- and sex-corrected occupancy values).

CONCLUSIONS

Higher D(2) receptor occupancy is associated with negative subjective experience in patients taking risperidone or olanzapine. These negative subjective effects may be related to the high discontinuation rates seen in usual practice. Understanding the neurobiological mechanism of these negative subjective experiences and developing antipsychotics with novel (i.e., non D(2)) mechanisms may be critical in improving the treatment of psychosis.

The selective effect of antipsychotics on the different dimensions of the experience of psychosis in schizophrenia spectrum disorders

While most standard symptom scales regard the 'psychotic' or 'positive' dimension of schizophrenia as a single factor, several lines of evidence suggest that psychosis itself is a multidimensional phenomenon. The foregoing literature suggested at least five distinct dimensions to psychosis; to test this, we developed, validated and applied an instrument to measure these dimensions and then applied it to examine the effect of antipsychotics on the different dimensions of the psychotic experience. The Dimensions of Psychosis Instrument (DIPI) was administered to 91 psychotic patients with schizophrenia spectrum disorders and a confirmatory factor analyses (CFA) was carried out to examine the five dimensions: cognitive preoccupation (CP) with the psychotic experience; emotional involvement (EM); behavioural impact (BI) of the experience; conviction (CO) in it; emotional; and external perspective (EP) about the experience. In a separate cohort of 17 prospectively treated patients, the impact of antipsychotics on these dimensions was assessed. BI showed the greatest improvement (32%) at 2 weeks, while CP and emotional improved somewhat less (22% and 14%, respectively). Improvement in CO was limited (6%) while EP showed no change. These results suggest that over the first few weeks of treatment, antipsychotics rapidly reduce the behavioural impact of the principal psychotic symptom and decrease cognitive and emotional preoccupation with it, without greatly altering the patients' conviction in or perspective about their psychotic experience.

The effect of age on the pharmacological management of ambulatory patients treated with depot neuroleptic medications for schizophrenia and related psychotic disorders

BACKGROUND

Cross-sectional studies indicate that, in comparison to younger patients, older schizophrenic patients have a higher risk for neuroleptic-induced Parkinsonism and tardive dyskinesia (TD). It has been suggested, therefore, that older patients with schizophrenia could be maintained on reduced doses of conventional neuroleptics.

METHOD

We examined the effect of age on psychopharmacological management in a naturalistic study of a group of 165 patients with a clinical diagnosis of schizophrenia or a related psychotic disorder (age range = 21-84 years; subjects > or = 1;45 years n = 86) treated with either haloperidol decanoate or fluphenazine decanoate.

RESULTS

Increasing age was not correlated with total daily dose of neuroleptics or anticholinergic medication. However, a modest negative correlation of age with daily neuroleptic dose was found in patients aged 45 years and older.

CONCLUSION

The results of this study highlight the need for prospective assessments of depot neuroleptic dose requirements in older patients suffering from primary psychotic disorders.