Inhibition of calcium-independent phospholipase A impairs agonist-induced calcium entry in keratinocytes

Background

In many cells, depletion of intracellular calcium (Ca²⁺) reservoirs triggers Ca²⁺ entry through store-operated Ca²⁺ channels in the plasma membrane. However, the mechanisms of agonist-induced calcium entry (ACE) in keratinocytes are not fully understood.

Objectives

This study was designed to determine if pharmacological inhibition of calcium-independent phospholipase A (iPLA₂) impairs ACE in normal human epidermal keratinocytes.

Methods

Confocal laser scanning microscopy was used to monitor the dynamics of Ca²⁺ signalling in keratinocytes loaded with the calcium-sensitive dye Fluo-4. Cells were stimulated with extracellular nucleotides [adenosine triphosphate (ATP) or uridine triphosphate (UTP)] or with lysophosphatidic acid (LPA), a bioactive lipid that regulates keratinocyte proliferation and differentiation.

Results

Both ATP and UTP induced Ca²⁺ release in primary human keratinocytes. This was not followed by robust Ca²⁺ influx when the experiments were performed in low Ca²⁺ (70 μmol L⁻¹) medium. Upon elevation of extracellular Ca²⁺ to 1·2 mmol L⁻¹, however, a biphasic response consisting of an initial Ca²⁺ peak followed by an elevated plateau was observed. The plateau phase was inhibited when cells were treated with bromoenol lactone, a specific pharmacological inhibitor of iPLA₂. These findings indicate that iPLA₂ activity is required for ACE in keratinocytes. LPA also evoked Ca²⁺ release in keratinocytes but failed to induce sustained Ca²⁺ entry even when extracellular Ca²⁺ was elevated to 1·2 mmol L⁻¹.

Conclusion

Our results demonstrate for the first time an important role for iPLA₂ in regulating ACE in primary human keratinocytes.

Dysglycemia in a community sample of people treated for schizophrenia: the Diabetes in Schizophrenia in Central-South Ontario (DiSCO) study

OBJECTIVE

Despite increasing recognition of schizophrenia as a risk factor for diabetes, the prevalence and correlates of dysglycemia in people with schizophrenia have not been adequately studied. Discerning the modifiable risk factors is crucial for developing diabetes prevention strategies in schizophrenia.

METHODS

Socio-demographic, clinical and recent laboratory data were compiled from the case records and supplemental sources of 1123 people treated for schizophrenia who were living across five different communities in the region.

RESULTS

Screening rates for fasting plasma glucose (FPG) varied between 63-100% across the five communities, while other metabolic indices were monitored less frequently. 39 subjects (3.5%) in the sample had an existing diagnosis of type 2 diabetes. Among the others, 845 (78%) had FPG measured in the preceding 6 months, with the following results: FPG < or = 5.6 mmol/l in 474 (56%), 5.6-6.9 mmol/l in 268 (31%), and > or = 7 mmol/l in 103 (12.2%) subjects. Dysglycemia (FPG > or = 5.6 mmol/l) was significantly associated with older age (odds ratio [OR] 1.031), longer duration of schizophrenia (OR 1.062), self reported family history of diabetes (OR 8.87), body mass index (OR 1.081), excess weight (OR 1.014) and independent living status (OR 1.779), while European ethnicity (OR 0.706) and regular physical activity (OR 0.958) lowered the risk. No statistically significant correlations were noted with gender, level of education or functioning, or the type of antipsychotic drug prescribed.

CONCLUSIONS

There was a two-fold increase in the prevalence of dysglycemia, while there was a substantial under-recognition of and intervention for, diabetes and pre-diabetes in this sample of people treated for schizophrenia.

Cognition, functioning and quality of life in schizophrenia treatment: results of a one-year randomized controlled trial of olanzapine and quetiapine

BACKGROUND

Cognitive deficits are recognized as a critical determinant of functional outcomes in schizophrenia; and second generation antipsychotic drugs have been touted for their potential to enhance cognitive functioning and community tenure.

OBJECTIVES

The study examined the relative merits of olanzapine and quetiapine in improving cognitive deficits and enhancing psychosocial functioning in a sample of community dwelling adults previously treated with first generation antipsychotic drugs for schizophrenia.

METHODS

In a prospective, rater-blinded study, 86 participants were randomized to receive either olanzapine or quetiapine, and assessed at baseline and after 3, 6, 9 and 12 months. Outcome measures included, besides symptoms and side effects rating scales, the subjective scale to investigate cognition in schizophrenia (SSTICS), a computer-assisted cognitive test battery (COGLAB), the sickness impact profile (SIP), the global assessment of functioning (GAF) scale, and the drug attitude inventory (DAI).

RESULTS

Both olanzapine and quetiapine were equally effective in improving symptom severity and decreasing the neurological side effects. Quetiapine was significantly better tolerated (p=0.002), improved self-rated cognitive dysfunction (p=0.002) and subjects' performance on selected neurocognitive tasks (p=0.01). Olanzapine use was associated with greater symptom stability, fewer drop outs (p=0.01) and frequent metabolic aberrations (p=0.001). The accrued benefits of drug therapy, however, were not reflected as significant gains in daily functioning and quality of life.

CONCLUSIONS

Quetiapine is noted to have specific cognition enhancing properties in schizophrenia that warrants further exploration. The observed clinical and cognitive benefits associated with quetiapine may likely be attributable to its loose binding to, and fast dissociation from the dopamine receptors. Olanzapine has proved to be a reliable antipsychotic drug with a greater liability to cause metabolic abnormalities.

Defining melancholia: the primacy of psychomotor disturbance

OBJECTIVE

To argue that melancholia is a categorically distinct depressive condition, able to be differentiated from other depressive conditions by a neuropathological marker [observable psychomotor disturbance (PMD)] and having a differential response to various antidepressant treatments.

METHOD

The above statements are addressed by review of a wide body of research, which identified observable PMD as the cardinal marker of melancholia and developed the CORE measure as a strategy for assessing PMD and its severity. Properties of the CORE measure, including reliability, validity and treatment prediction, are overviewed.

RESULTS

A case is made for defining melancholia and a strategy for establishing its probability.

CONCLUSION

Melancholia is positioned as a categorical entity capable of being circumscribed by its cardinal feature of PMD.

The validity and utility of patients' daily ratings of mood and impairment in clinical trials of bipolar disorder

OBJECTIVE

Traditional cross-sectional clinician-rated measures have limited use in clinical trials of bipolar disorder. We examine the validity and usefulness of patients' daily ratings of mood and functional impairment during a treatment trial.

METHOD

Ten subjects with bipolar II disorder completed daily ratings of depression severity, depression, hypomania and functional impairment over a 9-month trial. Ratings were correlated with clinician-rated measures at nine time points to determine validity. Mood ratings were contrasted with cross-sectional data for one subject to determine usefulness of such fine-grained data.

RESULTS

Moderate to large correlations were found between patients' and clinicians' ratings of mood and impairment for most of the nine time points. The utility of the patients' ratings relative to clinician-rated cross-sectional measures was also illustrated.

CONCLUSION

Results support the validity and usefulness of patients' daily mood ratings.

Treating depression with the evidence-based psychotherapies: a critique of the evidence

OBJECTIVE

While Cognitive Behaviour Therapy (CBT) and Interpersonal Therapy (IPT) have been positioned as first-line evidence-based treatments for depression, we suggest that limitations to the 'evidence' deserve wider appreciation.

METHOD

A systematic literature search was undertaken, and limitations to the evidence base discussed.

RESULTS

The review suggests that the specificity of CBT and IPT treatments for depression has yet to be demonstrated and details likely reasons.

CONCLUSION

The superiority of CBT and IPT may well be able to be demonstrated across defined rather than universal circumstances. To achieve this aim, outcome research should move away from testing treatments as if they have universal application for heterogeneous disorder categories. Findings have distinct implications for the clinical management of depressive disorders, and particularly in relation to the utility of psychotherapy.

Is post-Lipiodol CT better than i.v. contrast CT scan for early detection of HCC? A single liver transplant center experience

Hepatocellular carcinoma is a highly vascular neoplasm usually arising from a cirrhotic liver. Delayed, noncontrast, computed tomography (CT) imaging after 7 to 14 days reveals an oil-based contrast agent to be concentrated in the tumor but not in normal hepatic parenchyma. The aim of this study was to retrospectively correlate the post Lipiodol CT scan findings with respect to tumor size in the explanted liver. We retrospectively reviewed adult patients who had undergone orthotopic liver transplantation between November 1995 and December 2004 and also had an hepatic arteriogram with Lipiodol injection as part of their pretransplant workup. We calculated sensitivity, specificity, false-negativity, false-positivity, and accuracy of the test, as well as positive and negative predictive values. Lipiodol CT exam had sensitivity of 1.0; specificity of 0.6 with a calculated positive predictive value of 0.89 and a negative predictive value of 1.0. Overall accuracy of Lipiodol CT scan test was found to be 0.91, which was superior to an intravenous contrast CT alone. In conclusion, because of the higher sensitivity and accuracy values, hepatic arterial Lipiodol injection can be considered during the pretransplantation workup of high-risk cirrhotic patients, since the current model for End-stage Liver Disease scoring system for hepatocellular carcinoma is built on the ultimate bulk of the tumor. Further multicenter, controlled, large-volume prospective studies are warranted to verify this observation.

Actions taken to cope with depression in patients seeking specialist care

OBJECTIVE

To assess the rates and perceived effectiveness of actions used to cope with depression and the factors influencing these in an outpatient sample seeking help for depression.

METHOD

One hundred and seventy-six patients (74 male, 102 female) aged 16-82 years (M = 42, SD = 14.4 years) with a major depressive episode (DSM-IV criteria) were assessed using a number of measures that covered sociodemographics, history of psychiatric illness, actions taken to alleviate depression and their perceived effectiveness. Logistic regression analyses assessed age, gender and illness characteristics associated with the use and perceived effectiveness of strategies adopted to manage depression.

RESULTS

Medical interventions were used and perceived to be effective in alleviating depressive symptoms by most of the sample, as were self-help and complementary therapies. Sociodemographic and illness-related characteristics had a significant influence, with younger age and having experienced an episode of anxiety disorder found to be the strongest predictors for the use of coping strategies. Being female was the strongest predictor for their effectiveness.

CONCLUSION

A range of actions for depression, including medical and complementary interventions, were used and found to be helpful in a sample that had sought professional help for depression. Gender, age, depression and anxiety factors were all found to predict the use and perceived effectiveness of these strategies.

Sleeping in? The impact of age and depressive sub-type on hypersomnia

BACKGROUND

While early morning wakening is held to be a classic feature of melancholia, we investigate the clinical observation that young patients with melancholia and bipolar depression tend to be more likely to report hypersomnia.

METHODS

We examine age-related rates of those two sleep disturbance patterns in a consecutive set of out-patients with differing depressive sub-types assessed over a 20-year period.

RESULTS

Hypersomnia was more likely to be reported than early morning wakening across all age bands by those with non-melancholic depression. Hypersomnia was also more likely than early morning wakening in younger patients with melancholia and bipolar disorder but, with age, early morning wakening became the dominant pattern.

LIMITATIONS

The study was retrospective, undertaken in a sample attending a tertiary referral unit and artefactual determinants of the associations were not pursued.

CONCLUSIONS

We speculate that hypersomnia may be a non-specific homeostatic coping response to stress and thus to the non-melancholic depressive disorders, but that this pattern is overruled by an early morning wakening pattern in the more biological depressive sub-types as the individual ages, perhaps reflecting a noradrenergic contribution.

Self-harming in depressed patients: pattern analysis

OBJECTIVE

As deliberate self-harm (DSH) is a common concomitant of depressive disorders, we undertook a study examining the relevance of possible determinants and correlates of DSH.

METHOD

Three separate samples of depressed outpatients were studied to determine consistency of identified factors across samples, with principal analyses involving gender, age and diagnosis-matched DSH and non-DSH subjects.

RESULTS

Across the samples, some 20% of subjects admitted to episodes of DSH. Women reported higher rates and there was a consistent trend for higher rates in bipolar patients. Univariate analyses examined the relevance of several sociodemographic variables, illicit drug and alcohol use, past deprivational and abusive experiences, past suicidal attempts and disordered personality functioning. Multivariate analyses consistently identified previous suicide attempts and high 'acting out' behaviours across the three samples, suggesting the relevance of an externalizing response to stress and poor impulse control.

CONCLUSIONS

Results assist the identification and management of depressed patients who are at greater risk of DSH behaviours.

Antenatal screening for the prediction of postnatal depression: validation of a psychosocial Pregnancy Risk Questionnaire

OBJECTIVE

To assess the predictive value of an antenatal index of risk for postnatal depression (PND).

METHOD

Participants returned the Pregnancy Risk Questionnaire (PRQ; 18 antenatal items) and the Edinburgh Depression Scale (EDS) at a mean of 32 weeks gestation; the EDS was then mailed out at 2 and 4 months postpartum to ascertain those women who were screened positive (score>2), i.e. probable cases of depression. Only those returning the EDS at 2 and/or 4 months were included in the study (n=1296). Women who screened positive (n=322; 24.8%) were contacted and of these, 245 completed the Auto-Composite International Diagnostic Interview (CIDI) and form the basis of our primary analyses.

RESULTS

A CIDI diagnosis of major depression was found in 5.3% women at either 2 or 4 months. In this population, the optimal PRQ cut-off was >or=46 at which point sensitivity was 44% and specificity 92%. At this cut-off 9.9% tested positive (for risk of PND) on the PRQ with a positive predictive value (PPV) of 23.5%. Of 1079 women who scored below 46 on the PRQ, 3.2% were cases of CIDI depression while of those 119 scoring 46 or above, 23.5% were CIDI cases at 2 or 4 months postpartum, yielding an odds ratio of 9.18.

CONCLUSION

Using a cut-off of >or=46, the PRQ is better than previously reported tools in the antenatal prediction of PND with respect to sensitivity and specificity, while like other studies PPV remains limited. The PRQ allows identification of high and low risk groups and thus has applicability in both the research and clinical settings.

Progressing a spectrum model for defining non-melancholic depression

OBJECTIVE

To further develop a 'spectrum model' for non-melancholic disorders that encompasses underlying personality styles and clinical patterning.

METHOD

In a sample of patients with non-melancholic depression, we studied four personality constructs influencing risk to depression, assessing associational strength and specificity between personality scores and symptom and coping response patterns.

RESULTS

Analyses refined four personality dimensions (anxious worrying, irritability, social inhibition, and self-centredness) for testing the model. For all dimensions, personality style was specifically linked with a mirroring 'coping' response. Quantification of specific links allowed development of a spectrum model for the non-melancholic depressive disorders in which underpinning personality style showed some specific links with the clinical 'pattern' of symptoms and coping repertoires.

CONCLUSION

The model has the capacity to assist clinical assessment, identify aetiological personality influences and allow specific treatment effects for the heterogeneous non-melancholic depressive disorders to be determined.

Cranial venous outflow obstruction and pseudotumor Cerebri syndrome

The pathophysiology of PTS including idiopathic intracranial hypertension or 'BIH', remains controversial. The older literature frequently referred to pathology in the cerebral venous drainage but more modern imaging techniques (CT and early MR) failed to reveal gross venous pathology. The role of impaired cranial venous outflow has recently been re-examined in the light of new methods of investigation (advanced MR venography and direct microcatheter venography with manometry) and of treatment (venous sinus stenting). Venous sinus obstruction in PTS is a more common factor in the pathogenesis of the condition than previously recognised. Venous obstruction may be primary, that is, it is the underlying aetiological factor in PTS. Venous sinus obstruction may also be secondary to raised CSF pressure which may exacerbate problems with intracranial compliance and raised CSF pressure. Early experience with venous stenting suggests that it may be a helpful treatment for patients with PTS but more experience and longer follow-up is required to define the subgroups of patients for whom it is most appropriate.

Measuring disordered personality functioning: to love and to work reprised

OBJECTIVE

Current limitations to diagnosing and measuring the personality disorders encouraged a set of studies seeking to provide an alternate approach to modeling and measuring disordered personality function.

METHOD

A large set of self-reported descriptors of disordered personality function were factor analyzed in a sample of patients with clinician-diagnosed personality dysfunction, generating 11 lower-order and two higher-order constructs. Subjects and non-clinical controls also completed a measure of personality styles underpinning formalized personality disorder groupings. Properties of the refined self-report (SR) measure were assessed in an independent sample of patients with a clinically diagnosed personality disorder.

RESULTS

Limitations in 'cooperativeness' and 'coping' formed the higher-order constructs defining disordered personality function, with these constructs relevant to all personality styles. Analyses of SR, corroborative witness (CW) and clinician-rated data in an independent sample supported measuring disordered personality function by our derived 20-item SR measure, and exposed limitations to clinician-based assessment.

CONCLUSION

Study findings build to a multi-axial strategy for measuring personality disorder, involving separate dimensional assessment of both disordered personality function and of personality style.

ZD9331 as Second- or Third-Line Therapy in Patients With Advanced Colorectal Cancer

This study investigated the efficacy and tolerability of ZD9331 as second- or third-line treatment for patients with advanced colorectal cancer (aCRC). One hundred patients were recruited to the study: 45 in group 1 (failed first-line 5-FU-based regimen) and 55 in group 2 (failed first-line 5-FU-based regimen and second-line irinotecan). Patients received ZD9331 as a 30-minute intravenous infusion on days 1 and 8 of a 3-week cycle, and treatment continued until disease progression (PD) or withdrawal. After a median of 4 cycles of treatment, there were no objective responses in group 1 (N = 37), 25 (67.6%) patients had a best overall response of stable disease (SD), and 12 (32.4%) had PD. After a median of 3 cycles of treatment, there were 2 (4.5%) partial responses in group 2 (N = 44), 21 (47.7%) patients had a best overall response of SD, 20 (45.4%) had PD, and 1 (2.3%) had clinical progression. At data cut-off, 59.5% and 77.3% of patients in groups 1 and 2, respectively, had PD. The main adverse events were neutropenia (69%), fatigue (53%), nausea (46%), and diarrhea (40%), and most (72.3%) were grade I/II. ZD9331 demonstrated minimal antitumor activity, and manageable toxicity, in the second- or third-line treatment of aCRC.

Studying personality characteristics in bipolar depressed subjects: how comparator group selection can dictate results

OBJECTIVE

To examine the extent to which identification of any distinct personality characteristics in bipolar subjects are influenced by selection of the comparison diagnostic group.

METHOD

Scores were compared on several general measures of personality style and, additionally, the prevalence of disordered personality functioning was examined in a sample of 198 non-psychotic depressed subjects, 39 with bipolar depression and 159 with unipolar depression.

RESULTS

When the bipolar subjects were separately compared with unipolar subjects, and to sub-sets of those with clinically and DSM-IV defined melancholic and non-melancholic depression, quite differing results were suggested. In essence, clinically-defined melancholic subjects had the least personality psychopathology in comparison with the non-melancholic and bipolar subjects.

CONCLUSION

Whether subjects with bipolar disorder have any distinct personality characteristics or over-represented co-morbid personality disorders remains quite unclear when reference is made to the literature. We suggest that inconsistencies across studies may reflect choice and representation of depressive sub-types within the unipolar comparator group.

Is the female preponderance in major depression secondary to a gender difference in specific anxiety disorders?

BACKGROUND

While a female preponderance in unipolar depression is a consistent finding in community-based studies, determinants remain speculative. This study aimed to examine whether a female preponderance in certain anxiety disorders drives a gender difference in depression.

METHOD

The relevant data from the National Comorbidity Study (NCS) are analysed.

RESULTS

We observed a biphasic pattern in the emergence of a female preponderance in the depressive and anxiety disorders, with an initial pre-pubertal or early adolescent onset, and after attenuation in early to middle adulthood, re-emergence in mid- to late-adulthood. Analyses focused on determinants of the initial female preponderance. Female gender, presence of an anxiety disorder and variable ages of onset in the anxiety disorder all contributed to the increased chance of an initial depressive episode. Some specificity in linking the onset of depressive temporally in early adolescence with two anxiety disorders was demonstrated, specifically generalized anxiety disorder and panic disorder.

CONCLUSIONS

The separate anxiety disorders and their age of onset had variable links with depression, but female gender remained a significant predictor of depression after accounting for the effects of prior anxiety.

Studies in NZB IL-10 knockout mice of the requirement of IL-10 for progression of B-cell lymphoma

NZB mice develop an age-related malignant expansion of a subset of B cells, B-1 cells, with autocrine production of IL-10. IL-10, a pleiotropic cytokine with anti-inflammatory properties, is a potent growth and survival factor for malignant B cells. To further examine the in vivo requirement for IL-10 in the development and expansion of malignant B-1 clones in NZB mice, we developed a strain of homozygous IL-10 knockout (KO) mice on an NZB background. The NZB IL-10 KO mice develop peritoneal B-1 cells with approximately the same frequency as heterozygous and wild-type littermates. In contrast, the development of malignant B-1 cells in the peripheral blood and spleen, observed in wild-type NZB, rarely occurred in the NZB IL-10 KO. Phenotypic analysis of surface marker expression in splenic B cells indicated that, in contrast to the NZB with malignant B-1 splenic lymphoma, the surface marker expression of NZB IL-10 KO splenic B cells indicated that the majority of the B cells were typical B-2 cells. In the absence of IL-10, spontaneously activated B cells and antiapoptotic gene expression were reduced and lymphoma incidence was decreased. These results indicate that IL-10 is a critical factor for the progression of this B-cell malignant disease.

Modern diagnostic concepts of the affective disorders

OBJECTIVE

To review critically alternative models of depression.

METHOD

Contrasting historical models are noted and some results of a study overviewing a temperament-based model for the non-melancholic disorders are presented.

RESULTS

Limitations to all models are considered.

CONCLUSION

As depression can present as a mood state, a syndrome, a disorder and as a disease, it is unwise to assume that a single model will suffice. A pure temperament diathesis model of non-melancholic depression is unlikely to be sufficient and would benefit from testing of additional personality constructs.

Properties of the temperament and character inventory in a Chinese sample

OBJECTIVE

To determine the influence of language and culture on the temperament and character (TCI) measure in a Chinese sample.

METHOD

We translated the TCI into Mandarin and had a non-psychiatric sample of Malaysian Chinese subjects complete the TCI at baseline and at a 1-month retest, with subsets completing English or Mandarin versions alternatively or on both occasions. Analyses examine the TCI factor structure and any impact of language and culture on TCI scoring.

RESULTS

We identified age, gender, occupation and language effects on TCI scale scores. Test-retest reliability was high and not compromised by language. Scale internal consistency was also high. Factor analyses of separate sets of TCI scales corresponded strongly to the structure identified in the TCI development studies.

CONCLUSION

The results indicate that TCI is likely to have applicability to Chinese subjects, and argue against properties being constrained by the English language or by western culture.

An Australian validation study of the temperament and character inventory

OBJECTIVE

To assess the validity of the temperament and character inventory (TCI) measure in an Australian sample.

METHOD

A sample of depressed subjects completed the TCI and a measure assessing personality disorder constructs (PDCs), while family members and psychiatrists also returned PDC ratings.

RESULTS

Factor analyses generally supported the TCI constructs, when the temperament and character scales were analysed separately. Self-reported PDC scores were validated against corroborative witness ratings and used to assess the TCIs concurrent validity. Validation analyses supported all TCI temperament scales, but the Self-transcendence Character scale was unassociated with PDC scores. The remaining two character scales (i.e. cooperativeness and self-directedness) were non-specifically associated with all PDC scores.

CONCLUSION

Study results support the validity of the TCI scales, but question the best model for conceptualizing the TCI. It is suggested that two character scales quantify disordered functioning, while temperament scales quantify style, constructs that may be inter-related or independent in individual subjects.

Gender differences in response to differing antidepressant drug classes: two negative studies

BACKGROUND

A recent US study presented data suggesting that depressed women are more likely to respond to selective serotonin reuptake inhibitor (SSRI) than tricyclic (TCA) antidepressant drug therapies. We have undertaken replication studies in two independent databases.

METHOD

We have examined for gender differences in SSRI and TCA antidepressant response in both retrospective and prospective naturalistic uncontrolled studies, and in subsets of melancholic and non-melancholic depressed subjects. As the US study had indicated that women under the age of 40 years were particularly likely to show a differential response to SSRIs, we examined for age, gender and interactional effects. In addition, we examined for differential SSRI and TCA responsiveness in a subset of patients who had received drugs from both classes.

RESULTS

We failed to find evidence of women having a preferential response to SSRI medication or, conversely, of men having a superior response to TCA medication. Older age, however, was associated with a superior TCA response and younger age with a superior SSRI response.

CONCLUSION

As few studies have examined for differential gender and age effects in response to narrow action and broad action antidepressant drugs across major depressive subtypes, gender differential effects remain to be established.

Examination stress in Singapore primary schoolchildren: how compliance by subjects can impact on study results

OBJECTIVE

Examinations are anecdotally viewed as extremely stressful to Singapore schoolchildren. We test this postulate by obtaining parental ratings of children's emotional stress levels longitudinally in a large representative sample of sixth (P6) and fifth (P5) class primary schoolchildren, respectively, exposed and unexposed to a streaming examination.

METHOD

Children's stress levels were rated monthly by a parent for 10 months.

RESULTS

Analyses failed to find evidence of any differential stress impact across P6 and P5 comparison groups, apart from a subset of P6 children whose parents complied with every monthly survey.

CONCLUSION

The streaming examination in the final year of primary school did not emerge as a general stressor to children, but achieved salience within a defined subset of children whose parents were highly study compliant. Study compliance may be a proxy variable of some import, and have wider relevance to other cohort studies and to intervention trials.