Risk factors for the deficit syndrome of schizophrenia

Previous studies have found two risk factors associated with the deficit syndrome of schizophrenia: an increase in summer births, compared to others with schizophrenia; and a higher risk of schizophrenia in relatives. In data from the Camberwell Register Psychosis Series, a population-based sample that approximated a treated-incidence sample, the deficit/nondeficit categorization was made using a previously validated proxy method. Associations were found between the deficit syndrome and both summer birth and a family history of schizophrenia. In contrast, nondeficit schizophrenia was associated with a family history of psychiatric problems other than schizophrenia. The deficit group also had poorer insight. An early age of onset was associated with disorganization, but not with the deficit or nondeficit group. The deficit/nondeficit differences could not be attributed to confounding by demographic features or the severity of hallucinations, delusions, or formal thought disorder.

A clinical validation of the Dysmorphic Concern Questionnaire

OBJECTIVE

The current study addressed the concept of dysmorphic concern as a symptom that may exist in a number of disorders. The aims of the study were to: (i) validate a recently developed questionnaire that measures dysmorphic concern, the Dysmorphic Concern Questionnaire (DCQ); and (ii) evaluate the relationship of dysmorphic concern to depressed mood, social phobia, and obsessive-compulsive symptomatology.

METHOD

Sixty-five psychiatric inpatients were diagnosed using the computerized version of the Composite International Diagnostic Interview (CIDI-A). They then completed the DCQ, and questionnaires measuring body dysmorphic disorder (the Body Dysmorphic Disorder Examination, or BDDE), depression, social phobia, and obsessive-compulsive disorder (OCD). The factor structure and convergent validity of the DCQ were determined, and associations with mood and anxiety symptoms explored.

RESULTS

The DCQ was found to be a reliable and valid instrument that is sensitive to dysmorphic concern. Furthermore, although dysmorphic concern was associated with body dysmorphic disorder (BDD), depression, social phobia and OCD, only the score from the BDDE predicted DCQ score in a multiple regression analysis. Finally, BDD symptomatology was best defined by the presence of negative body beliefs as measured by the DCQ.

CONCLUSIONS

Negative body beliefs are the hallmark of BDD. However, the existence of dysmorphic concern does not necessarily imply a diagnosis of BDD. The DCQ is a quick and efficient means of identifying dysmorphic concern in those who present with depression, OCD, social phobia or BDD.

The use of seclusion in the year 2000: What Has Changed?

This study was undertaken to examine the perceptions of nurses working in three psychiatric settings regarding the effect and use of seclusion. It also aimed to identify current practices at these sites in the metropolitan area of Western Australia. A total of 78 nurses specialising in mental health care participated in the study by completing the 'Attitude towards seclusion survey'. The findings of this study indicate that nurses perceive seclusion as an accepted patient management strategy. The results also showed that the decision to seclude the patient was made by a senior mental health practitioner and that one hour was the average time a patient spent in seclusion. It is important to ensure that punishment, paternalistic attitudes or punitive actions are not part of clinical judgment regarding the use of seclusion. The study has provided evidence of nurses' perceptions concerning seclusion and the results highlight the need for staff to continue to explore and evaluate issues that lead to seclusion in order to facilitate the use of other management strategies that encourage a less restrictive environment.

A cognitive-behavioural, group-based intervention for social anxiety in schizophrenia

OBJECTIVE

The objective of this study was to investigate the efficacy of group-based cognitive-behavioural therapy (CBT) for social anxiety in schizophrenia.

METHOD

Patients with schizophrenia (20) with comorbid social anxiety were randomly assigned to the group-based CBT or wait-list control condition. Pre-, post- and 6-week follow-up ratings included measures of social anxiety and avoidance, mood and quality of life.

RESULTS

The intervention group improved on all outcome measures and the control group showed no change in symptomatology.

CONCLUSIONS

Group-based CBT is effective in treating social anxiety in schizophrenia.

The secretory carrier membrane protein family: structure and membrane topology

Secretory carrier membrane proteins (SCAMPs) are integral membrane proteins found in secretory and endocytic carriers implicated to function in membrane trafficking. Using expressed sequence tag database and library screens and DNA sequencing, we have characterized several new SCAMPs spanning the plant and animal kingdoms and have defined a broadly conserved protein family. No obvious fungal homologue has been identified, however. We have found that SCAMPs share several structural motifs. These include NPF repeats, a leucine heptad repeat enriched in charged residues, and a proline-rich SH3-like and/or WW domain-binding site in the N-terminal domain, which is followed by a membrane core containing four putative transmembrane spans and three amphiphilic segments that are the most highly conserved structural elements. All SCAMPs are 32-38 kDa except mammalian SCAMP4, which is approximately 25 kDa and lacks most of the N-terminal hydrophilic domain of other SCAMPs. SCAMP4 is authentic as determined by Northern and Western blotting, suggesting that this portion of the larger SCAMPs encodes the functional domain. Focusing on SCAMP1, we have characterized its structure further by limited proteolysis and Western blotting with the use of isolated secretory granules as a uniformly oriented source of antigen and by topology mapping through expression of alkaline phosphatase gene fusions in Escherichia coli. Results show that SCAMP1 is degraded sequentially from the N terminus and then the C terminus, yielding an approximately 20-kDa membrane core that contains four transmembrane spans. Using synthetic peptides corresponding to the three conserved amphiphilic segments of the membrane core, we have demonstrated their binding to phospholipid membranes and shown by circular dichroism spectroscopy that the central amphiphilic segment linking transmembrane spans 2 and 3 is alpha-helical. In the intact protein, these segments are likely to reside in the cytoplasm-facing membrane interface. The current model of SCAMP1 suggests that the N and C termini form the cytoplasmic surface of the protein overlying a membrane core, which contains a functional domain located at the cytoplasmic interface with little exposure of the protein on the ectodomain.

Psychotic disorders in urban areas: an overview of the Study on Low Prevalence Disorders

OBJECTIVE

This paper reports on a study designed within the framework of the National Survey of Mental Health and Wellbeing to: estimate the prevalence of psychoses in urban areas of Australia; identify profiles of symptomatology, impairments and disabilities; collect information on services received and needed; and explore quality of life issues in a broadly representative sample of people with psychotic illnesses.

METHOD

The study was conducted over four areas in the Australian Capital Territory, Queensland, Victoria and Western Australia, as a two-phase survey: (i) a census and screening for psychosis of all individuals who made contacts with mental health services during a period of 1 month in 1997; and (ii) interviews with a stratified random sample (n=980) of the screen-positive individuals (n=3800) using a standardised instrument.

RESULTS

The point prevalence (1 month) of psychotic disorders in the urban population aged 18-64 is in the range of 4-7 per 1000 with a weighted mean of 4.7 per 1000. People with psychotic disorders experience high rates of functional impairments and disability, decreased quality of life, persistent symptoms, substance-use comorbidity and frequent side effects of medication. Although the utilisation of hospital-based and community mental health services, as well as of public and non-governmental helping agencies, is high, the majority live in extreme social isolation and adverse socioeconomic circumstances. Among the many unmet needs, the limited availability of community-based rehabilitation, supported accommodation and employment opportunities is particularly prominent.

CONCLUSIONS

The so-called 'low-prevalence' psychotic disorders represent a major and complex public health problem, associated with heavy personal and social costs. There is a need for a broad programmatic approach, involving various sectors of the community, to tackle the multiple dimensions of clinical disorder, personal functioning and socioeconomic environment that influence the course and outcome of psychosis and ultimately determine the effectiveness of service-based intervention.

Analyses of proteins involved in vesicular trafficking in platelets of mouse models of Hermansky Pudlak syndrome

Hermansky Pudlak syndrome (HPS) is an autosomal recessive inherited disorder characterized by defects in synthesis and/or secretion of three related subcellular organelles: melanosomes, platelet-dense granules, and lysosomes. In the mouse, mutant forms of any of 14 separate genes result in an HPS-like phenotype. The mouse pearl and mocha genes encode subunits of the AP3 adaptor protein complex, confirming that HPS mutations involve proteins regulating intracellular vesicular trafficking. Therefore, expression of several additional proteins involved in vesicular transport was examined by immunoblotting of platelet extracts from HPS mutant and control mice. Platelet levels of SCAMPS (secretory carrier membrane proteins), Rab11, Rab31, NSF (N-ethylmaleimide-sensitive fusion protein), syntaxin 2, syntaxin 4, munc18c, and p115/TAP (p115/transcytosis-associated protein) were not significantly altered in several different HPS mutants. However, gunmetal (gm/gm) platelets contained decreased amounts of SNAP-23. The Snap23 gene was mapped to mouse chromosome 5, demonstrating it cannot encode the gm gene, which maps to chromosome 14. It is likely therefore that the gm gene functions upstream of SNAP-23 in vesicular trafficking.

Differences in distribution of ages of onset in males and females with schizophrenia

An earlier age at onset of schizophrenia in men as opposed to women, has been widely reported, but hitherto, insufficient account has been taken of parameters that might confound this finding. Furthermore, few explanatory models have accounted for the differences in shape of the age-at-onset distributions in males and females with schizophrenia. A catchment area sample of 477 first contact cases with schizophrenia or related disorders was ascertained through a case register. Differences in age at onset distributions between males and females were determined, and adjustment made for potential confounding factors. The most powerful predictors of early illness-onset were poor premorbid occupational functioning, single marital status, and male sex. The earlier onset in males was robust to controlling for other parameters. The shape of the onset distribution also differed between the sexes: SKUMIX analysis revealed a two-peak distribution for males, and a three-peak distribution for females. The mean age at onset for schizophrenia is earlier in males, and the onset distribution differs between the sexes. Psychosocial variables cannot explain these findings. Possible explanations for these gender differences include males and females being differentially susceptible to subtypes of illness with different mean ages at onset; precipitating and/or ameliorating factors operating at different stages of life in males and females; and/or an X-linked susceptibility locus that determines the age at onset.

Relocation of the t-SNARE SNAP-23 from lamellipodia-like cell surface projections regulates compound exocytosis in mast cells

For regulated secretion, mast cells and several other cell types utilize compound exocytosis, a combination of granule-plasma membrane and granule-granule fusions. The molecular machinery that controls this massive export process has not been identified. We report that SNAP-23, a t-SNARE related to SNAP-25, relocates in response to stimulation from plasma membrane lamellipodia-like projections to granule membranes in permeabilized mast cells. While relocation is a prerequisite for secretion, it can occur without membrane fusion and will expedite a subsequent secretory response. After relocation, SNAP-23 is required for exocytosis, implying a crucial role in promoting membrane fusion. Thus, relocation of this SNARE regulates compound exocytosis and links granule-plasma membrane and granule-granule fusions.

Sorting and storage during secretory granule biogenesis: looking backward and looking forward

Secretory granules are specialized intracellular organelles that serve as a storage pool for selected secretory products. The exocytosis of secretory granules is markedly amplified under physiologically stimulated conditions. While granules have been recognized as post-Golgi carriers for almost 40 years, the molecular mechanisms involved in their formation from the trans-Golgi network are only beginning to be defined. This review summarizes and evaluates current information about how secretory proteins are thought to be sorted for the regulated secretory pathway and how these activities are positioned with respect to other post-Golgi sorting events that must occur in parallel. In the first half of the review, the emerging role of immature secretory granules in protein sorting is highlighted. The second half of the review summarizes what is known about the composition of granule membranes. The numerous similarities and relatively limited differences identified between granule membranes and other vesicular carriers that convey products to and from the plasmalemma, serve as a basis for examining how granule membrane composition might be established and how its unique functions interface with general post-Golgi membrane traffic. Studies of granule formation in vitro offer additional new insights, but also important challenges for future efforts to understand how regulated secretory pathways are constructed and maintained.

Intracellular transport and secretion of salivary proteins

Intracellular transport and secretion of salivary proteins are major activities of salivary acinar cells. While the major intracellular pathway followed by salivary proteins following their synthesis has been described previously, there is only limited understanding of how this process is regulated at the molecular level. Studies of salivary proteins, especially proline-rich proteins, expressed in an endocrine cell line have begun to provide insight regarding intermolecular interactions during transport and the role played by structural signals during intracellular sorting. Analysis of the secretion of newly synthesized salivary proteins in parotid tissue has shown that there are multiple pathways of discharge from acinar cells. While granule exocytosis is the major pathway, at least two other pathways that export salivary proteins have been found to originate from maturing secretion granules. These pathways may contribute to other acinar cell functions, including secretion of proteins in the absence of acute stimulation and support of the secretory process for fluid and electrolytes.

Influenza epidemics and incidence of schizophrenia, affective disorders and mental retardation in Western Australia: no evidence of a major effect

In-utero exposure to influenza has been implicated as a risk factor for developmental CNS damage. This study tests the hypothesis that in-utero exposure to influenza: (1) in the second gestational trimester is associated with an increased risk of schizophrenia and affective psychoses; and (2) in the first gestational trimester is associated with an increased risk of mental retardation. Analysis was confined to 1852 cases on the Western Australian psychiatric case register with ICD-9 diagnoses of schizophrenia, affective psychoses, or neurotic depression (comparison group), and 804 cases on the Intellectual Handicap Register with mental retardation that were related to 82,963 'exposed' and 32,462 'non-exposed' births between 1950 and 1960 in the total population of Western Australia. The data were examined for effects associated with six influenza epidemics in the period 1950-1960. Using relative risk ratios for individual epidemics as well as Poisson regression and a proportional hazards model to examine systematic effects for the whole period, no major effect could be identified for maternal influenza on the incidence of schizophrenia, affective psychoses and neurotic depression, despite sufficient statistical power to detect an effect. However, a possible effect was found for mental retardation in males exposed in the first and second gestational trimester.

Evidence for a genetic association between alleles of monoamine oxidase A gene and bipolar affective disorder

We present evidence of a genetic association between bipolar disorder and alleles at 3 monoamine oxidase A (MAOA) markers, but not with alleles of a monoamine oxidase B (MAOB) polymorphism. The 3 MAOA markers, including one associated with low MAOA activity, show strong allelic association with each other but surprisingly not with MAOB. Our results are significant only for females, though the number of males in our sample is too small to draw any definite conclusions. Our data is consistent with recent reports of reduced MAOA activity in patients with abnormal behavioral phenotypes. The strength of the association is weak, but significant, which suggests that alleles at the MAOA locus contribute to susceptibility to bipolar disorder rather than being a major determinant.

Does influenza cause schizophrenia? A five year review

Over the last five years a body of literature has been generated concerning whether or not prenatal exposure to influenza results in an increased risk of developing schizophrenia in the exposed offspring. The studies are reviewed with respect to the traditional epidemiological criteria that help to define causality. There is a modest degree of consistency in support of an association between the 1957 influenza epidemic--and less so, for influenza epidemics in general--and later schizophrenia. Two cohort studies examining the 1957 epidemic do not support an association. The strength and specificity of the association remain weak. The proposed association draws coherence from the neurodevelopmental hypothesis of schizophrenia. Suggestions are made for future research that could add to our understanding of the putative association between influenza and schizophrenia.

Genetic association between alleles of pancreatic phospholipase A2 gene and bipolar affective disorder

Chromosome 12q is a region of interest for the genetics of bipolar affective disorder because of reports of apparent cosegregation between this disorder and Darier's disease in a small number of families. Findings from a recent linkage study suggest that this chromosomal region may contain a susceptibility gene for bipolar affective disorder. We have found evidence of an allelic association between bipolar disorder and a marker at the pancreatic phospholipase A2 gene (PLA2A) in this region (p < or = 0.01). These results are consistent with the linkage study, and warrant additional investigations.

No evidence of association between dopamine D4 receptor variants and bipolar affective disorder

Disturbance in the dopamine neurotransmitter system has been implicated in the pathogenesis of affective disorder. In this study, we examine the possibility that functional variants of the recently cloned dopamine D4 receptor gene contribute to the genetic component of manic depression. The polymorphism, a 48 bp tandem repeat coding for part of the third cytoplasmic loop, was detected using a PCR based method. In a first sample of 57 patients and 59 controls, we found allele 7 to be in excess in the patients. In contrast, allele 3 was less frequent in patients. A second, larger sample of 90 patients and 91 controls was utilized to test these hypotheses. Data from the two samples were then pooled together for further analyses. We calculated the power of our samples, and if the frequency of 7 repeat allele obtained from sample 1 is true, i.e., 25% (28/114) for patients and 14% (16/118) for controls, then the power of the combined sample is 62% at 5% (two-tailed) significance level. However, both observations were not replicated; we therefore conclude that variations in this repeat at the DRD4 gene do not contribute to the genetic component of manic depression.

The criminal careers of incident cases of schizophrenia

We present a population-based, longitudinal study of all incident cases (N = 538) of schizophrenia in the London Borough of Camberwell between 1964 and 1984. Cases were selected from the Camberwell Cumulative Psychiatric Case Register. Case-notes were obtained, and further classified using a computerized operational check list for rating psychotic illness. Cases are not restricted to hospital discharges, as in previous studies, and account is taken of time at liberty to offend. In order to test the hypothesis that schizophrenia makes an independent contribution to criminality over other mental disorders, controls were chosen to be representative of nonschizophrenic mental disorders matched for age, sex and period. The rate of conviction is increased in women with schizophrenia compared to other mental disorders for most offence categories (rate ratio = 3.3). In men overall rates do not differ (rate ratio = 1.03), although there is an interaction between gender, schizophrenia and ethnicity, with young black men with schizophrenia being most at risk. The rate ratio for violent offences in men with schizophrenia is 3.8, confirming recent studies from Sweden. Subjects with schizophrenia were more likely to acquire any criminal record than those with other mental disorders. The rate of lifetime conviction was greater in those with schizophrenia than either a sample of working-class boys from the same area followed by Farrington & West, or National data. The risk of first conviction is increased by schizophrenia, unemployment, ethnic group, substance abuse and low social class, and decreased by being employed, married, female and older age of onset. Adjustment using survival analysis showed that schizophrenia made a small independent contribution to the risk of acquiring a criminal record (hazard ratio = 1.4) but gender, substance abuse, ethnicity and age of onset were more substantial. Previous criminality was the strongest independent association of post-illness conviction, with schizophrenia only a trend. Although subjects with schizophrenia were more likely to acquire a criminal record, criminal careers began later and were shorter than those of the controls. The risk of criminality increased throughout the study period, but suggestions of a specific increase in those with schizophrenia as a result of changes in community care were not confirmed. These results confirm that women with schizophrenia are at increased risk of acquiring a criminal record, but the effect in men is for violent convictions only. The strongest associations of criminal conviction remain those recognized in non-schizophrenic subjects.

Association and haplotype analysis at the tyrosine hydroxylase locus in a combined German-British sample of manic depressive patients and controls

Tyrosine hydroxylase (TH) is the key enzyme in the synthesis of catecholamines and may therefore be of aetiological relevance in the development of psychiatric illness. Hipolar affective disorder association studies, with restriction fragment length polymorphisms located in flanking regions of the TH gene, have shown conflicting results. Alleles of a tetranucleotide repeat polymorphism (TH4) located in intron 1 of the gene were tested for association with bipolar affective disorder in a combined German and British sample of 183 bipolar patients and 209 healthy control probands. No differences in TH4 allele frequencies were found in the two groups. A subset of patients and controls was typed with the flanking markers Ty7/BglII and pJ4.7/TaqI and frequencies of two-locus haplotypes were estimated. Linkage disequilibrium was found between TH4-Ty7 and TH4-pJ4.7. Haplotype frequencies did not differ between patients and controls.

A comparative study of 470 cases of early-onset and late-onset schizophrenia

The presence or absence of 22 schizophrenic symptoms was recorded with the age at onset of illness in 470 patients with non-affective, non-organic psychoses. Positive and negative formal thought disorder, affective symptoms, inappropriate affect, delusions of grandiosity or passivity, primary delusions other than delusional perception, and thought insertion and withdrawal were all more common in early-onset cases (age at onset 44 years or less; n = 336). Persecutory delusions with and without hallucinations, organised delusions, and third-person, running commentary and accusatory or abusive auditory hallucinations were all more common in late-onset cases (age at onset 45 years or more; n = 134). There was no difference between cases of early and late onset in the prevalence of delusions of reference, bizarre delusions, delusional perception, or lack of insight. We conclude that although there are clinical similarities between cases of schizophrenia with early and late onset, there are sufficient differences between them to suggest that they are not phenotypically homogeneous.