Risk-taking in schizophrenia and controls with and without cannabis dependence

BACKGROUND

Risk-based decision making is altered in people with schizophrenia and in people with cannabis use compared to healthy controls; the pattern of risk-assessment in people with co-occurring schizophrenia and cannabis dependence is poorly understood. This study examined measures of risk-taking and decision-making in people with and without schizophrenia and/or cannabis dependence.

METHODS

Participants with schizophrenia (n=24), cannabis dependence (n=23), schizophrenia and co-occurring cannabis dependence (n=18), and healthy controls (n=24) were recruited from the community via advertisements and completed a one-visit battery of symptom, risk-based decision making, gambling behavior, cognitive, and addiction assessments. This report presents self-assessments of self-mastery, optimism, impulsivity, and sensation seeking and a behavioral assessment of risk (Balloon Analog Risk Task [BART]).

RESULTS

On self-report measures, participants with schizophrenia and co-occurring cannabis dependence were intermediate between those with only cannabis dependence or only schizophrenia on ratings of self-mastery, sensation-seeking, and impulsivity. There were no group differences on ratings of optimism. Their behavior on the BART was most similar to participants with only cannabis dependence or healthy controls, rather than to participants with only schizophrenia.

CONCLUSIONS

People with schizophrenia and co-occurring cannabis dependence may represent a unique group in terms of risk-perception and risk-taking. This has implications for interventions designed to influence health behaviors such as motivational interviewing.

Influence of kynurenine 3-monooxygenase (KMO) gene polymorphism on cognitive function in schizophrenia

BACKGROUND

Cognitive deficits compromise quality of life and productivity for individuals with schizophrenia and have no effective treatments. Preclinical data point to the kynurenine pathway of tryptophan metabolism as a potential target for pro-cognitive drug development. We have previously demonstrated association of a kynurenine 3-monooxygenase (KMO) gene variant with reduced KMO gene expression in postmortem schizophrenia cortex, and neurocognitive endophenotypic deficits in a clinical sample. KMO encodes kynurenine 3-monooxygenase (KMO), the rate-limiting microglial enzyme of cortical kynurenine metabolism. Aberration of the KMO gene might be the proximal cause of impaired cortical kynurenine metabolism observed in schizophrenia. However, the relationship between KMO variation and cognitive function in schizophrenia is unknown. This study examined the effects of the KMO rs2275163C>T C (risk) allele on cognitive function in schizophrenia.

METHODS

We examined the association of KMO polymorphisms with general neuropsychological performance and P50 gating in a sample of 150 schizophrenia and 95 healthy controls.

RESULTS

Consistent with our original report, the KMO rs2275163C>T C (risk) allele was associated with deficits in general neuropsychological performance, and this effect was more marked in schizophrenia compared with controls. Additionally, the C (Arg452) allele of the missense rs1053230C>T variant (KMO Arg452Cys) showed a trend effect on cognitive function. Neither variant affected P50 gating.

CONCLUSIONS

These data suggest that KMO variation influences a range of cognitive domains known to predict functional outcome. Extensive molecular characterization of this gene would elucidate its role in cognitive function with implications for vertical integration with basic discovery.

Gluten sensitivity and relationship to psychiatric symptoms in people with schizophrenia

The relationship between gluten sensitivity and schizophrenia has been of increasing interest and novel mechanisms explaining this relationship continue to be described. Our study in 100 people with schizophrenia compared to 100 matched controls replicates a higher prevalence of gluten sensitivity and higher mean antigliadin IgG antibody levels schizophrenia (2.9 ± 7.7 vs. 1.3 ± 1.3, p = 0.046, controlled for age). Additionally, we examined symptoms within the schizophrenia group and found that while positive symptoms are significantly lower in people who have elevated antigliadin antibodies (AGA; 4.11 ± 1.36 vs. 6.39 ± 2.99, p = 0.020), no robust clinical profile differentiates between positive and negative antibody groups. Thus, identifying people in schizophrenia who may benefit from a gluten-free diet remains possible by blood test only.

Detecting reliable cognitive change in individual patients with the MATRICS Consensus Cognitive Battery

OBJECTIVE

Clinicians often need to evaluate the treatment response of an individual person and to know that observed change is true improvement or worsening beyond usual week-to-week changes. This paper gives clinicians tools to evaluate individual changes on the MATRICS Consensus Cognitive Battery (MCCB). We compare three different approaches: a descriptive analysis of MCCB test-retest performance with no intervention, a reliable change index (RCI) approach controlling for average practice effects, and a regression approach.

METHOD

Data were gathered as part of the MATRICS PASS study (Nuechterlein et al., 2008). A total of 159 people with schizophrenia completed the MCCB at baseline and 4weeks later. Data were analyzed using an RCI and a regression formula establishing confidence intervals.

RESULTS

The RCI and regression approaches agree within one point when baseline values are close to the sample mean. However, the regression approach offers more accurate limits for expected change at the tails of the distribution of baseline scores.

CONCLUSIONS

Although both approaches have their merits, the regression approach provides the most accurate measure of significant change across the full range of scores. As the RCI does not account for regression to the mean and has confidence limits that remain constant across baseline scores, the RCI approach effectively gives narrower confidence limits around an inaccurately predicted average change value. Further, despite the high test-retest reliability of the MCCB, a change in an individual's score must be relatively large to be confident that it is beyond normal month-to-month variation.

Multimodal white matter imaging to investigate reduced fractional anisotropy and its age-related decline in schizophrenia

We hypothesized that reduced fractional anisotropy (FA) of water diffusion and its elevated aging-related decline in schizophrenia patients may be caused by elevated hyperintensive white matter (HWM) lesions, by reduced permeability-diffusivity index (PDI), or both. We tested this hypothesis in 40/30 control/patient participants. FA values for the corpus callosum were calculated from high angular resolution diffusion tensor imaging (DTI). Whole-brain volume of HWM lesions was quantified by 3D-T2w-fluid-attenuated inversion recovery (FLAIR) imaging. PDI for corpus callosum was ascertained using multi b-value diffusion imaging (15 b-shells with 30 directions per shell). Patients had significantly lower corpus callosum FA values, and there was a significant age-by-diagnosis interaction. Patients also had significantly reduced PDI but no difference in HWM volume. PDI and HWM volume were significant predictors of FA and captured the diagnosis-related variance. Separately, PDI robustly explained FA variance in schizophrenia patients, but not in controls. Conversely, HWM volume made equally significant contributions to variability in FA in both groups. The diagnosis-by-age effect of FA was explained by a PDI-by-diagnosis interaction. Post hoc testing showed a similar trend for PDI of gray mater. Our study demonstrated that reduced FA and its accelerated decline with age in schizophrenia were explained by pathophysiology indexed by PDI, rather than HWM volume.

Psychological predictors of functional outcome in people with schizophrenia

BACKGROUND

There is increasing evidence that psychological factors (e.g., defeatist performance beliefs, trait negative affect) contribute to poor functional outcome in people with schizophrenia. In the current study, we evaluated whether multiple psychological factors predict poor functional outcome in individuals with schizophrenia, and whether associations between psychological variables and functional outcome persist even after accounting for neuropsychological impairment and negative symptoms.

METHODS

100 patients meeting diagnostic criteria for schizophrenia or schizoaffective disorder and 78 demographically matched healthy control subjects completed self-report psychological measures, neuropsychological testing, and clinical rating scales.

RESULTS

Self-report scales assessing negative affectivity, defeatist performance beliefs, anhedonia, and behavioral inhibition were significantly correlated with functional outcome in people with schizophrenia. Neuropsychological impairment was associated with vocational outcome, whereas most of the self-report measures were related to social outcome. Defeatist performance attitudes were not correlated with neuropsychological performance.

CONCLUSIONS

Self-report measures predict variance in functional outcome beyond measures of clinical symptomatology and neuropsychological impairment. Findings indicate that psychological factors may be meaningful targets for psychosocial interventions aimed at improving functional outcome in schizophrenia.

The relationship between working memory capacity and broad measures of cognitive ability in healthy adults and people with schizophrenia

OBJECTIVE

Working memory (WM) capacity, typically measured with cognitively complex span tasks, is correlated with higher order cognitive abilities in healthy adults. The goals of this study were to determine whether a more focused measure of visual WM storage capacity would show similar higher order ability correlations in healthy adults and in people with schizophrenia (PSZ), thereby demonstrating the importance of simple storage capacity; determine whether the illness alters the pattern of correlations across cognitive domains; and evaluate whether between-groups differences in WM capacity could account for the generalized cognitive impairment in PSZ.

METHOD

Ninety-nine PSZ and 77 healthy controls (HCs) completed a visual WM change-localization task, the Wechsler Abbreviated Scale of Intelligence (WASI), and the MATRICS Consensus Cognitive Battery (MCCB).

RESULTS

PSZ performed more poorly than HCs on all cognitive measures. The between-groups effect size for WM capacity was large (d = 1.11). WM robustly correlated with WASI and MCCB performance, with no significant differences in the magnitude or pattern of correlations across groups. When the groups were pooled, WM capacity correlated at r = .68 with MCCB composite score and at r = .56 with WASI estimated Full Scale IQ. WM capacity accounted for approximately 40% of the between-groups variance across the WASI and MCCB.

CONCLUSIONS

A simple measure of WM storage capacity is robustly associated with the higher order cognitive abilities assessed by the WASI and MCCB in HCs and PSZ. WM capacity reduction may be a critical determinant of the general cognitive impairment in PSZ.

Treating symptomatic hyperprolactinemia in women with schizophrenia: presentation of the ongoing DAAMSEL clinical trial (Dopamine partial Agonist, Aripiprazole, for the Management of Symptomatic ELevated prolactin)

Prolactin elevations occur in people treated with antipsychotic medications and are often much higher in women than in men. Hyperprolactinemia is known to cause amenorrhea, oligomenorrhea, galactorrhea and gynecomastia in females and is also associated with sexual dysfunction and bone loss. These side effects increase risk of antipsychotic nonadherence and suicide and pose significant problems in the long term management of women with schizophrenia. In this manuscript, we review the literature on prolactin; its physiology, plasma levels, side effects and strategies for treatment. We also present the rationale and protocol for an ongoing clinical trial to treat symptomatic hyperprolactinemia in premenopausal women with schizophrenia. More attention and focus are needed to address these significant side effects and help the field better personalize the treatment of women with schizophrenia.

Comparison of the effectiveness of Conners' CPT and the CPT-identical pairs at distinguishing between smokers and nonsmokers with schizophrenia

Sustained attention deficits and high rates of smoking are often observed in patients with schizophrenia. This has led to the hypothesis that patients may smoke as an attempt to ameliorate cognitive deficits related to abnormal nicotinic structure and function. Continuous performance tasks (CPT) are often used to index sustained attention deficits in patients with schizophrenia, however, there are important differences between tasks that may impact performance in smokers and nonsmokers with schizophrenia differently. The Conners' CPT (C-CPT) has a high signal-to-noise ratio and is commonly used to assess impulsivity. The CPT-Identical Pairs (CPT-IP) has a low signal-to-noise ratio and is commonly used to assess negative symptoms in patients with schizophrenia. We sought to determine whether there were differences of sustained attention between patient smokers vs. nonsmokers, and if one CPT would provide a better separation of sustained attention between groups. Results revealed that both instruments detect more impaired sustained attention deficits in patient smokers compared to nonsmokers. Patient smokers performed significantly worse on the majority of the CPT-IP composite scores compared to the C-CPT composite scores. These results do not support the self-medication theory, as patient smokers performed worse than patient nonsmokers. Researchers studying sustained attention in schizophrenia may wish to consider the CPT-IP over the C-CPT, as well as control for smoking status.

General intellectual ability does not explain the general deficit in schizophrenia

Patients with schizophrenia demonstrate a generalized deficit across multiple cognitive domains. However, it is unknown whether this deficit is largely due to lower intelligence, or if there is an impact of schizophrenia which cannot be accounted for by measures of general intellectual ability (GIA). We created four IQ-matched strata of equal width between 89 healthy volunteers (HC) and 77 patients with schizophrenia (SZ) who had very similar IQ and reading scores within each stratum, then compared each stratum's performance on the MATRICS Consensus Cognitive Battery (MCCB). We hypothesized that any patient impairment on the MCCB after matching on IQ would be evidence that GIA does not fully explain the general deficit seen in schizophrenia. We found that patients showed evidence of greater neuropsychological impairment than what would be expected based solely on their IQ and reading ability scores. Further, this deficit was stronger in some cognitive domains than others, namely, processing speed and social cognition. These results suggest the presence of a distinction between GIA and generalized neuropsychological impairment that was consistent in magnitude across all patients, regardless of IQ.

Participants with schizophrenia retain the information necessary for informed consent during clinical trials

OBJECTIVE

Cognitive impairment is a characteristic of schizophrenia. This impairment may affect the retention of information required for ongoing knowledgeable participation in clinical trials. This study monitored retention of study-related knowledge-including assessment of therapeutic misconception-in people with stable, DSM-IV schizophrenia during participation in placebo-controlled clinical trials of adjunctive agents. Stability was defined as being on an antipsychotic with no change in medication or dose over the previous 4 weeks.

METHOD

This longitudinal study assessed retention of clinical trial-related consent information. Individuals enrolling in 1 of 8 clinical trials were approached for participation. Participants came from research clinics and community mental health centers. At baseline, clinical trial consent forms were reviewed and study knowledge assessed. Participants were randomized to follow-up assessments at weeks 1, 4, and 8; weeks 4 and 8; or at week 8 only. Clinical trial consent forms were not rereviewed at any follow-up visit.

RESULTS

Fifty-nine participants were enrolled; analysis included 52 participants with at least 1 follow-up visit. Study knowledge did not decrease meaningfully in any group. Therapeutic misconception was not observed in participants during the study. The group assessed most frequently demonstrated significant improvement over baseline (t44 = 3.43, P = .001). Retention of study knowledge was not related to symptoms but had a weak correlation with cognitive capacity (R = 0.28, P = .07). Performance did not differ between participants from research clinics and those from community mental health centers.

CONCLUSIONS

Clinically stable people with schizophrenia enrolling in a placebo-controlled adjunctive medication study, once determined to have capacity to consent to a clinical trial, retained appropriate study knowledge for at least 8 weeks. In the absence of a specific reason to suspect a loss of decisional capacity, there appears to be no need to routinely reevaluate participants during this type of clinical trial.

Effects of adjunctive intranasal oxytocin on olfactory identification and clinical symptoms in schizophrenia: results from a randomized double blind placebo controlled pilot study

BACKGROUND

Deficits in olfactory identification have been widely reported in patients with schizophrenia (SZ) and are associated with negative symptomatology. Adjunctive oxytocin delivered intranasally has been shown to improve some aspects of social cognition as well as positive and negative symptoms in patients with schizophrenia. Given the intranasal delivery route of oxytocin to olfactory pathways and that olfactory abnormalities are a potential endophenotype in SZ, we investigated the effect of intranasal oxytocin on olfactory identification as well as positive and negative symptoms in people with schizophrenia.

METHODS

Individuals with schizophrenia or schizoaffective disorder (n=28; 16 outpatients, 12 inpatients) were randomized to receive adjunctive intranasal oxytocin 20 IU BID or placebo for 3 weeks.

RESULTS

All 28 participants completed the clinical trial. Odor identification performance significantly improved on the University of Pennsylvania Smell Identification Test (UPSIT) total score and subscore for pleasant smells. UPSIT score (F=5.20, df=1,23, p=0.032) and subscore for pleasant smells (F=4.56, df=1,23, p=0.044), in patients treated with oxytocin were compared to placebo from baseline to endpoint. Global symptomatology as well as positive and negative symptoms were not improved by intranasal oxytocin. In fact, global symptoms, not positive or negative symptoms, improved in the placebo group. Secondary analysis shows that intranasal oxytocin improved negative symptoms in the small group of inpatients. Intranasal oxytocin was well tolerated during the three week trial.

CONCLUSION

Adjunctive intranasal oxytocin may improve olfactory identification, particularly in items of positive valence. Larger studies are needed to determine the effects of oxytocin on negative symptoms in SZ. (NCT00884897; http://www.clinicaltrials.gov).

The roles of reward, default, and executive control networks in set-shifting impairments in schizophrenia

Patients with schizophrenia (SZ) show deficits on tasks of rapid reinforcement learning, like probabilistic reversal learning (PRL), but the neural bases for those impairments are not known. Recent evidence of relatively intact sensitivity to negative outcomes in the ventral striatum (VS) in many SZ patients suggests that PRL deficits may be largely attributable to processes downstream from feedback processing, involving both the activation of executive control task regions and deactivation of default mode network (DMN) components. We analyzed data from 29 chronic SZ patients and 21 matched normal controls (NCs) performing a PRL task in an MRI scanner. Subjects were presented with eight pairs of fractal stimuli, for 50 trials each. For each pair, subjects learned to choose the more frequently-rewarded (better) stimulus. Each time a criterion was reached, the better stimulus became the worse one, and the worse became the better. Responses to feedback events were assessed through whole-brain and regions-of-interest (ROI) analyses in DMN. We also assessed correlations between BOLD signal contrasts and clinical measures in SZs. Relative to NCs, SZ patients showed comparable deactivation of VS in response to negative feedback, but reduced deactivation of DMN components including medial prefrontal cortex (mPFC). The magnitudes of patients' punishment-evoked deactivations in VS and ventromedial PFC correlated significantly with clinical ratings for avolition/anhedonia. These findings suggest that schizophrenia is associated with a reduced ability to deactivate components of default mode networks, following the presentation of informative feedback and that motivational deficits in SZ relate closely to feedback-evoked activity in reward circuit components. These results also confirm a role for ventrolateral and dorsomedial PFC in the execution of response-set shifts.

Cannabis withdrawal in chronic cannabis users with schizophrenia

BACKGROUND

Chronic users of cannabis often report withdrawal symptoms after abstinence from use, but little is known about cannabis withdrawal in people with schizophrenia.

METHODS

Cannabis use patterns and withdrawal symptoms in adults with schizophrenia who had at least weekly cannabis use before attempting to quit without formal treatment were assessed with the Marijuana Quit Questionnaire (MJQQ), a 176-item, semi-structured questionnaire.

RESULTS

120 participants, predominantly African-American (62.5%) and male (76.7%), met inclusion criteria. 20.1% reported that their first regular cannabis use (median age 15 years [range 8-48]) preceded their age at first psychotic symptoms (20 [4-50] years). Twenty (16.7%) participants met lifetime criteria for cannabis abuse; 98 (81.7%) met surrogate criteria for lifetime cannabis dependence. Withdrawal symptoms were reported by 113 (94.2%) participants, with 74.2% reporting ≥4 symptoms. The most frequently reported withdrawal symptoms were craving for cannabis (59.2%), feeling anxious (52.57%), feeling bored (47.5%), feeling sad or depressed (45.8%), feeling irritable or jumpy (45.0%), feeling restless (43.3%), and trouble failing asleep (33.3%). One hundred-and-four (92.0%) participants took some action to relieve at least one of their withdrawal symptoms during their index-quit attempt, including 26 (23.0%) participants who reported resuming cannabis use.

CONCLUSION

Cannabis withdrawal is a clinically significant feature of cannabis use among people with schizophrenia, may serve as a negative reinforcer for relapse, and deserves greater attention in treatment and research. Clinical Trials registration NCT00679016.

Tolerance to effects of high-dose oral δ9-tetrahydrocannabinol and plasma cannabinoid concentrations in male daily cannabis smokers

Oral cannabinoids are taken for medicinal or recreational purposes, yet little is known about tolerance to their effects after high-dose extended exposure. The development of tolerance to effects of around-the-clock oral synthetic Δ9-tetrahydrocannabinol (THC) (20 mg every 3.5-6 h) was evaluated in 13 healthy male daily cannabis smokers residing on a secure research unit: 40 mg on Day 1; 100 mg on Days 2-4; 120 mg on Days 5-6. Systolic and diastolic blood pressure (BP), heart rate, and symptoms of subjective intoxication (100 mm visual-analogue scales, VAS) were assessed the morning of Day 1 (before any oral THC), and on Days 2, 4 and 6, every 30 min for 3 h after the first morning THC dose. Morning subjective intoxication ratings increased from Days 1 to 2, and then declined on Days 4 and 6. The morning THC dose increased intoxication ratings on Day 2, but had less effect on Days 4 and 6, a pattern consistent with tolerance. THC lowered BP and increased heart rate over the six days. Plasma THC and 11-OH-THC concentrations increased significantly over the first five days of dosing. Six days of around-the-clock, oral THC produced tolerance to subjective intoxication, but not to cardiovascular effects.

Illicit drug use in heavy smokers with and without schizophrenia

OBJECTIVE

The prevalence of cigarette smoking among people with schizophrenia is greater than that of the general population. Because smoking and use of other drugs covary, we examined illicit drug use in current smokers not trying to quit or reduce their tobacco use. We recruited outpatient participants who had a DSM-IV diagnosis of schizophrenia or schizoaffective disorder (schizophrenia, n=70) and a control group who had no Axis I psychiatric disorders (control, n=97). During a 2-3-hour session, participants completed demographic and research questionnaires, including the Drug Use Survey (DUS).

RESULTS

Participants with schizophrenia were older than controls (p<0.001) and smoked more cigarettes per day (p=0.01), but did not differ in degree of nicotine dependence. Ever using a drug was similar between the groups, except that significantly more participants with schizophrenia reported ever using hallucinogens (p<0.001) and inhalants (p=0.001). For alcohol, cocaine, and marijuana, fewer participants with schizophrenia were current users, but more participants with schizophrenia were past users (ps<0.0001). Heavy smokers from the general population continued to use illicit drugs throughout their lives, while schizophrenia participants had the highest period of illicit drug use in their 20s.

CONCLUSIONS

These data suggest that illicit drug use tends to be high in heavy cigarette smokers, regardless of a schizophrenia diagnosis. However, while illicit drug use is high across the lifespan of heavy smokers in the general population, heavy smokers with schizophrenia use illicit drugs mostly in the first decade of their illness.

Cervical cancer screening and acute care visits among Medicaid enrollees with mental and substance use disorders

OBJECTIVE

This study compared rates of cervical cancer screening and acute care (primary or gynecological) visits among women with and without a diagnosis of psychosis, substance use disorder, bipolar disorder or mania, or depression.

METHODS

Using data about women (N=105,681) enrolled in Maryland's Medicaid program in fiscal year 2005, the authors constructed logistic models with cancer screening and acute care visits as dependent variables and serious mental illness flags as independent variables. Covariates were age, race, geography, Medicaid eligibility category, and sexually transmitted diseases. The logistic model of cervical cancer screening outcomes was repeated with acute care visits as a covariate.

RESULTS

Women with psychosis (N=4,747), bipolar disorder or mania (N=3,319), or depression (N=5,014) were significantly (p<.05) more likely than women in a control group without such disorders (N=85,375) to receive cancer screening (adjusted odds ratio (AOR) range=1.46-1.78) and to have associated acute care visits (AOR range=1.45-2.15). Compared with those in the control group, women with a substance use disorder, with (N=1,104) or without (N=6,122) psychosis, demonstrated reduced odds of cancer screening (AOR=.80) but similar odds of acute care visits (AOR=1.04). Acute care visits were strongly correlated with cancer screens. Genital cancer prevalence did not significantly differ among diagnostic groups.

CONCLUSIONS

In Maryland Medicaid, the odds of cancer screening and related acute care visits were greater for women with major mental disorders compared with women in the control group. For women with substance use disorders, however, screening was reduced and acute care visits were similar compared with women in the control group. Providers should encourage and support their patients with substance use disorders to increase use of preventive care services by primary care physicians and gynecologists.

Clinical characteristics of heavy and non-heavy smokers with schizophrenia

Up to 50-90% of persons with schizophrenia smoke cigarettes. Limited data and theories suggest persons with schizophrenia may smoke for different reasons than persons without schizophrenia, making smoking cessation interventions particularly challenging in this population. Although health consequences of smoking are widely known, less information is available regarding characteristics of different amounts of smoking exposure in this population. This study was performed to investigate differences between heavy (≥ 1 pack per day) and non-heavy (<1 pack per day) smoking in patients with schizophrenia. Data from 745 patients, mean age 41.3+/-12.6 years, were drawn from a population of smokers admitted to State of Maryland inpatient mental health facilities (1994-2000). Records were reviewed to obtain demographic information, diagnosis, medication, smoking and substance use. 43% of patients were characterized as heavy smokers. Heavy and non-heavy groups did not differ in age, GAF, weight, or BMI. No differences were found in race, gender or antipsychotic treatments. However, patients smoking ≥ 1 packs per day were more likely to use other substances such as alcohol (χ(2)=6.67, df=1, p=0.01), cocaine (χ(2)=6.66, df=1, p=0.01), and other substances (χ(2)=9.95, df=1, p=0.003) compared to non-heavy smokers. No differences in cannabis or heroin use were found by smoking category. Controlling for age, race, sex and BMI, heavy smokers had higher total cholesterol (190.7(51.6)mg/dL) compared to non-heavy smokers (178.2 (43.0)mg/dL, p=0.03), but no differences were found in glucose or blood pressure. Heavy smoking may be a particular health risk in schizophrenia and significant efforts for smoking cessation or reduction are needed.

Perception of smoking risks and motivation to quit among nontreatment-seeking smokers with and without schizophrenia

OBJECTIVE

We examined perceived consequences/benefits of cigarette smoking and motivation for quitting in nontreatment-seeking smokers who had schizophrenia or schizoaffective disorder (N = 100) or had no Axis I psychiatric disorder (normals, N = 100).

METHODS

Participants completed questionnaires and provided a breath carbon monoxide (CO) sample 10-15 minutes after smoking 1 preferred-brand cigarette. Primary assessments included the Smoking Consequences Questionnaire-Adult, the Reasons for Quitting Scale, and the Stages of Change.

RESULTS

There were no differences between the schizophrenia and control group in mean age of smoking onset (16.2 ± 5.4 vs 15.6 ± 5.5 y, P = .44), number of cigarettes daily (17.9 ± 11.6 vs 17.0 ± 7.9, P = 0.51), or in breath CO (28.0 ± 14.5 vs 22.9 ± 8.0 ppm, P = .61). Compared with normals, people with schizophrenia report greater stimulation/state enhancement (P < .0001) and social facilitation (P < .004) from smoking. People with schizophrenia had less appreciation of health risks associated with smoking than normal controls (P < .0001) and were less motivated to quit smoking than normal controls (P = .002), even though they were as likely to be in the preparation stage of change. Immediate reinforcement (P = .04) and health concerns (P = .002) were rated lower as motivators for considering quitting smoking in schizophrenia than normals. People with schizophrenia reported greater motivation to stop smoking due to social pressure/rewards than normals (P = .047).

CONCLUSIONS

This study underscores the degree to which people with schizophrenia perceive the state-enhancing effects of smoking and their lower appreciation for health risks of smoking compared with normal controls.

Cortical structural abnormalities in deficit versus nondeficit schizophrenia

OBJECTIVE

To examine the structural integrity of the dorsolateral prefrontal-basal ganglia-thalamocortical circuit in people with the deficit form of schizophrenia.

METHOD

A three-dimensional structural MRI sequence was used to conduct morphometric assessments of cortical and subcortical regions in deficit and nondeficit outpatients with schizophrenia and healthy controls.

RESULTS

The superior prefrontal and superior and middle temporal gyral gray matter volumes were significantly smaller in the deficit versus the nondeficit group and normal control groups. There were no significant group differences in examined subcortical structures.

CONCLUSION

People with deficit schizophrenia are characterized by selective reductions in the prefrontal and temporal cortex.

Effect of the neuroprotective peptide davunetide (AL-108) on cognition and functional capacity in schizophrenia

BACKGROUND

Cognitive dysfunction is a key predictor of functional disability in schizophrenia. Davunetide (AL-108, NAP) is an intranasally administered peptide currently being developed for treatment of Alzheimer's disease and related disorders. This study investigates effects of davunetide on cognition in schizophrenia.

METHOD

Sixty-three subjects with schizophrenia received davunetide at one of two different doses (5, 30 mg) or placebo for 12 weeks in a multicenter, double-blind, parallel-group randomized clinical trial. The MATRICS Consensus Cognitive Battery (MCCB) assessed cognitive effects. The UCSD Performance-based Skills Assessment (UPSA) and the Schizophrenia Cognition Rating Scale (SCoRS) assessed functional capacity. Subjects continued their current antipsychotic treatment during the trial.

RESULTS

There were no significant differences in MCCB change between davunetide and placebo over the three treatment arms (p=.45). Estimated effect-size (d) values were .34 and .21 favoring the 5 and 30 mg doses vs. placebo, respectively. For UPSA, there was a significant main effect of treatment across study arms (p=.048). Between-group effect size (d) values were.74 and .48, favoring the 5 and 30 mg doses, respectively. No significant effects were observed on the SCoRS or on symptom ratings. No significant side effects or adverse events were observed.

CONCLUSION

Davunetide was well tolerated. Effects of davunetide on MCCB-rated cognition were not significant relative to placebo. In contrast, a significant beneficial effect was detected for the UPSA. Based upon effect-size considerations, sample sizes of at least 45-50 subjects/group would be required to obtain significant effects on both MCCB and UPSA, providing guidance for continued clinical development in schizophrenia.

Rimonabant for neurocognition in schizophrenia: a 16-week double blind randomized placebo controlled trial

OBJECTIVE

To examine the effect of rimonabant on neurocognitive impairments in people with schizophrenia.

METHODS

Participants entered a 16-week double-blind, placebo-controlled, randomized clinical trial. A neurocognitive battery was administered at baseline and end of study.

RESULTS

In comparison to rimonabant (20mg/day), placebo-treated participants exhibited a significant improvement on the Repeatable Battery for the Assessment of Neuropsychological Status total score. In contrast, rimonabant was associated with significant improvement on a probabilistic learning task. There were no other significant treatment effects.

CONCLUSIONS

Rimonabant did not improve global cognitive functioning, but did improve a specific learning deficit based on response to positive feedback.