What do we know about the aetiology of late-onset schizophrenia?

Association of rs4680 COMT, rs6280 DRD3, and rs7322347 5HT2A With Clinical Features of Youth-Onset Schizophrenia

We investigated the associations of rs4680 COMT, rs6280 DRD3, and rs7322347 5HT2A with youth-onset schizophrenia in the Russian population in a case-control study, and the role of the genotype in the severity of clinical features. The association between rs7322347 and schizophrenia (p = 0.0001) is described for the first time. Furthermore, we found a link with rs6280 and rs4680 in females (p = 0.001 and p = 0.02 respectively) and with rs7322347 in males (p = 0.002). Clinical symptoms were assessed on three scales: the Clinician-Rated Dimensions of Psychosis Symptom Severity scale, Positive and Negative Syndrome Scale, and Frontal Assessment Battery. Gender differences in clinical features are of particular interest. In our study we found gender differences in the severity of clinical features-higher scores for delusions (Positive and Negative Syndrome Scale and Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition) in males and higher scores for depression, delusions, somatic concern, motor retardation, poor attention were found in females.

Risk factors in early and late onset schizophrenia

BACKGROUND

This study looks at key risk factors in patients with schizophrenia to identify trends according to age of onset, comparing presentations prior to 26years (youth onset), between 26 and 40years (middle onset), and after 40years of age (late onset).

METHODS

The early psychosis program at St Vincent's Hospital Melbourne treats patients presenting in the early stages of psychosis between 16 and 65years of age. A database was developed to capture key risk factors in all patients with an eventual diagnosis of schizophrenia (n=225). Risk factor profiles were then generated and compared for patients based on age of onset.

RESULTS

Older age of onset was associated with weaker family history of schizophrenia, lower rates of substance use, better early psychosocial functioning and higher educational achievement. Female preponderance and comorbid physical health problems were particularly notable in the late onset cohort. Later life schizophrenia also showed a relatively greater association with psychosocial factors proximal to psychosis onset, such as unemployment.

DISCUSSION

Clear trends are noticeable with age. Older patients have characteristic differences in their background risk factors compared to youth onset patients, including less hereditary influence and relatively more emphasis on later life risk factors. Identifying the roles of specific risk factors in these distinct age-onset groups can enhance our understanding of underlying aetiology and facilitate service development to meet the needs of each specific age group.

Clinical characteristics of patients with non-affective, non-organic, late onset psychosis

OBJECTIVE

Schizophrenia and related psychotic disorders are predominantly studied in young population. However some individuals do develop psychotic disorder for the first time during their old age. The aim of this study is to look at the clinical characteristics of non-affective, non-organic, late onset psychosis.

PARTICIPANTS AND METHODS

Retrospective chart review study, medical records of all patients registered between 1st of January 2006 and 31st May 2011 at geriatric clinic in NIMHANS, Bangalore was screened, 83 files with a diagnosis of late onset psychosis and meeting the study criteria were systematically analyzed.

RESULTS

The mean age at onset of illness was 67±10years; 98.8% were married, females formed 67.5% of the sample, commonest phenomenon was delusions followed by hallucinations, 80.5% of the subjects had delusion of persecution, 38.5% had referential delusion, 51.8% had accusative and derogatory auditory hallucinations, negative symptoms was seen only in 2.4% of subjects, none had formal thought disorder. 3.6% had co-morbid Axis II diagnosis.

CONCLUSION

Despite its rarity non affective, non organic, late onset psychosis forms a distinct group with unique manifestation. Further systematic research is needed for better understanding of this condition.

Schizophrenia: still Kraepelin's Dementia Praecox?

Summary

Asking whether E. Kraepelin's early dementia praecox and disease concepts (1896) are still valid today, we condensed his early theory into four theses:1) schizophrenia is a disease entity, distinguishable from affective psychosis. 2) It is caused by a specific neuropathology. 3) It usually manifests itself in adolescence or early adulthood. 4) Underlying schizo- phrenia is a progressive disease process that leads to defects and dementia.

Having tested whether Kraepelin's dementia praecox and modern schizophrenia are actually comparable, we studied 1) how schizophrenia and depression are linked or separable in terms of symptoms, risk factors and illness course from onset until five years after first treatment contact. The analyses are based on a population-based sample of 130 first admissions because of schiz- ophrenia, 130 age- and sex-matched first admissions because of unipolar depressive disorder and 130 “healthy” population con- trols from the study area. 2) Results will be presented that, though not very specific, confirm Kraepelin's farsighted hypothesis of a neuropathological basis of the disorder. In this context it will be discussed whether the brain changes are developmental or degenerative in origin. 3) The distribution of age of onset extends far into old age. In a sample of 1109 consecutive first admis- sions because of nonaffective psychosis from the total age range it was shown that age-dependent developmental factors mod- ify certain components of symptomatology linearly and significantly. The main risk factors, too, significantly change with age. 4) Long-term course was examined in three studies of epidemiologically recruited first-episode samples: Study 1 included five cross sections over 5 years, Study 2 was a prospective pre-post-comparison over 12 years supplemented by a retrospective assessment of the illness course (IRAOS) and Study 3 encompassed 10 cross sections over fifteen years. Finally, the disease concept of schizophrenia, as it presents itself in the light of current knowledge, will be outlined and compared with Kraepelin's earlier and later view of the disorder.

Declaration of Interest

the paper is based on a lecture (Lettura magistrale) presented at the SIEP Sesto Congresso Nazionale, “Gli Esiti della Schizofrenia - Trattamenti, Pratica nei Servizi, Valutazione” in Sirmione, November 6-8, 2003. Unfortunately, the illustrations shown there and some 20 % of the relevant references could not be included in this printed ver- sion for lack of space. This paper was written within the framework of the German Research Network on Schizophrenia and was funded by the German Federal Ministry for Education and Research BMBF (grant 01GI 0236). The ABC study was supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) as part of the Special Research Branch (Sonderforschungsbereich) 258 at the Central Institute of Mental Health until December 1998. From January 1999 to Sept. 2002 it was continued to be funded by the DFG.

Schizophrénie tardive ou délires chroniques

HISTORICAL ASPECTS

Chronic delusion occurring late in life has essentially been studied by European psychiatrists. "Late-onset schizophrenia" was first described and defined by Manfred Bleuler in 1943, as a form of schizophrenia which occurs after the age of 40. Later, British psychiatrists often used the term "Late-onset paraphrenia" interchangeably with "Late-onset schizophrenia" to designate this disorder. However, late-onset paraphrenia is a British concept which includes all delusional disorders starting after age 60. American psychiatrists had little interest in this patient group, so it is only within the DSM III-R that a separate category was created for patients who developed schizophrenia after age 44. There is now no longer a "late-onset" category for schizophrenia within the DSM IV, nor age criterion for the diagnosis of schizophrenia. In the French nosography, schizophrenia is excluded when a non-affective, non-organic psychosis begins after the age of 40. These chronic delusion syndromes fall into a specific French category: "Psychose Hallucinatoire Chronique" (chronic hallucinatory psychosis).

LITERATURE FINDINGS

Basing themselves on the analysis of many studies, the authors endeavor to define the characteristics of late-onset schizophrenia. The exact prevalence is not known, but is considered lower than 1%. There is a preponderance of women over men in this form of disease, that could be explained by the relative excess of dopamine type 2 (D2) receptors in young men (compared with young women), and by a protective role played by estrogens until the menopause, among women predisposed to schizophrenia. Studies of families reveal a lower lifetime risk of schizophrenia in first degree relatives of patients with late-onset schizophrenia, than those with an early onset. Most of these patients have been or are married, and had worked for a long time. Generally at the onset of the illness they are isolated and unemployed. Paranoid and schizoid abnormal premorbid personality traits are frequently noted with the diagnosis of late-onset schizophrenia. An association between late-onset schizophrenia and sensory impairment (visual and auditory) is frequently observed and appear to be in link with auditory and visual hallucinations. The analysis of clinical features reveal that the later the schizophrenia breaks out, the more the patient shows delusion and hallucinatory symptoms, which remain limited to his surroundings, whereas in younger patients, delusion has no limit. Moreover, late-onset schizophrenic patients have a lower prevalence of looseness of associations and negative symptoms than those with an earlier onset. The authors note from the few studies on the treatment, that a number of patients responded well to low dose of antipsychotic agents. The use of "atypical" anti-psychotic drugs is recommended, in order to reduce the adverse effects, notably the extrapyramidal symptoms which are frequent in elderly people.

CONCLUSION

Finally, they conclude that patients with late-onset schizophrenia have symptoms very similar to those of patients with early-onset schizophrenia. But, when taking the different forms of schizophrenia - even the late onset ones - into account, raises the question of the role of trigger factors that could guide research on predictive factors and early diagnosis. This may be one explanation for the survival of the French entity "Psychose Hallucinatoire Chonique".

Psychological processes underlying delusional thinking in late-onset psychosis: a preliminary investigation

BACKGROUND AND AIMS

It has been suggested that delusions may serve as a defence against negative self-representations. The present study investigated general psychological well-being and evidence for defensive emotional processes among people with late-onset psychosis.

METHOD

The performance and responses of older people with late-onset psychosis (n = 13), older people with depression (n = 15), and age-matched healthy controls (n = 15) were compared in a cross-sectional design. Participants rated their own levels of depression and self-esteem, and completed an emotional Stroop task to establish whether there was evidence of implicit depression in the absence of explicit acknowledgement. Participants rated themselves on a number of personal attributes in relation to two life stages to generate discrepancies in 'actual', 'ideal' and 'other' self-concepts, and completed measures of their perceptions of current and past psychological well-being.

RESULTS

People with late-onset psychosis showed no evidence of overt depression or low-self esteem. All three groups showed an attentional bias to depression-related and age-related words, although response times overall were faster for controls. The psychosis group showed no discrepancies between either their past or their current 'actual' and 'other' self-concepts, suggesting that they do not have more negative views about how others see them.

CONCLUSIONS

Evidence from this study does not support the application of the 'delusion-as-defence' model to late-onset psychosis, but methodological constraints must be borne in mind when interpreting the findings.

Psychopathology of early-onset versus late-onset schizophrenia revisited: an observation of 473 neuroleptic-naive patients before and after first-admission treatments

Reports of potential differences in psychopathological presentations between early and late-onset schizophrenia have been controversial. However, such differences in first-episode neuroleptic-naive schizophrenic patients have not been discussed. The authors evaluated symptom profiles in 473 neuroleptic-naive schizophrenic patients before and after first-admission treatments. Both before and after treatment, (1) late-onset schizophrenia had a lower score on affective flattening/social withdrawal than did the earlier-onset counterpart of the illness, even after controlling for potential secondary sources of negative symptoms; (2) systematic persecutory delusion was more severe in patients with late-onset schizophrenia; and (3) the overall effect of age of onset on the psychopathological presentations was greater than the gender-related effects, including the interaction between age of onset and gender. Consideration of late-onset schizophrenia may be important in order to develop an etiologically and clinically reasonable conceptualization of the subtypes of schizophrenia. A factor-analytical study that attempts to compare directly the structure of broad psychopathological presentations in early and late-onset schizophrenia may be a reasonable approach to investigate the longstanding unsolved controversy as to whether or not the neurobiological backgrounds underlying the psychopathological presentations are comparable.

The French concept of "psychose hallucinatoire chronique" -a preliminary form of schizophrenia? The role of late-life psychosis in the anticipation hypothesis of schizophrenia

The distinction between schizophrenia and chronic delusional syndromes (including the French concept of “psychose hallucinatoire chronique” [PHC] or chronic psychotic hallucinations, paraphrenia, and late paraphrenia) is currently used in various European countries, although there are no international criteria for chronic and bizarre delusions. The French concept of PHC is characterized by late-onset psychosis, predominantly in females, with rich and frequent hallucinations, but almost no dissociative features or negative symptoms. PHC and late-onset schizophrenia may have risk factors in common, which may help differentiate these disorders from young-onset schizophrenia, especially with regard to the potential role of (i) the estradiol hypothesis; (ii) the impact of sensory deficit; (Hi) putative specific brain abnormalities; or (iv) specific genetic mutations. In accordance with this hypothesis, and taking into account the familial aggregation analyses of PHC, here we evaluate the possibility that PHC represents a less severe form of schizophrenia, which would partly explain the “Sherman paradox” also observed in schizophrenia. The Sherman paradox describes the fact that multiplex families frequently have only one affected ascendant, meaning that an isolated sporadic case is at the origin of a highly loaded family. We thus propose that if unstable mutations are involved in the risk for schizophrenia, then PHC might represent a moderate disorder belonging to the schizophrenia spectrum phenotype.

Late paraphrenia: a variant of schizophrenia manifest in late life or an organic clinical syndrome? A review of recent evidence

A large amount of research has been devoted during the past 15 years to the clinical and neurobiological aspects of the disorder named as 'late paraphrenia' (LP) in 1955. The symptomatology and diagnosis of the disorder, its prognosis, the cognitive functioning of those affected, the structural changes in the brain as revealed by modern techniques of brain imaging and its postmortem neuropathology have all been submitted to investigation. The results have been widely regarded as consistent with the concept of LP as an organic disease of the brain, but increased knowledge of the neurobiology of schizophrenia and of the age-related changes that occur in the brains of elderly people casts doubt on the validity of this interpretation. The findings are consistent with the view that LP is the form in which schizophrenia is manifest in old age. The proposal that LP has a closer kinship with affective disorder than with schizophrenia is part of a general theory of the sex differences in schizophrenia. In LP it becomes entangled with the organicity hypothesis, suggesting that neither of these explanations is adequate, and most of the evidence points to a unitary concept which views LP as a variant of a single disorder, namely schizophrenia, which, however, requires a broad definition. This concept has implications for fresh paths of enquiry.

Therapeutic targets in late-life psychoses: review of concepts and critical issues

Psychoses in late life are a diagnostic challenge because of disagreement over how these entities should be classified. The main diagnostic categories of late-life psychoses include dementia with psychotic symptoms, late-onset schizophrenia, delusional disorder, early-onset psychotic disorders extending through late life, late-onset mood disorders, psychotic disorders caused by medical conditions or medications, and delirium. First onset of psychotic symptoms in late life is commonly associated with identifiable structural brain abnormalities and reflects underlying brain pathology. We reviewed the available literature on late-life psychotic manifestations, focusing on diagnostic classification and treatment approaches. Antipsychotics are the mainstay of treatment for these conditions, but should be used cautiously in elderly patients because of their increased sensitivity to side effects. Overall, appropriate research data on the effectiveness of various antipsychotic agents for late-life psychotic conditions are lacking. Non-antipsychotic psychotropic medications may be of value in managing some of these conditions.

A controlled family study of late-onset non-affective psychosis (late paraphrenia)

BACKGROUND

The relationship between those schizophrenia-like conditions that have their onset in late life and early-onset schizophrenia is unclear. Very few family history studies of patients with late-onset psychosis have been reported, and it is not known whether their relatives have an increased risk of psychosis.

METHOD

Information was collected on the psychiatric morbidity of 269 first-degree relatives of patients with schizophrenia or delusional disorder with an onset after the age of 60 (late paraphrenia), and 272 first-degree relatives of healthy elderly control subjects, using a research diagnostic instrument.

RESULTS

With a narrow age range (15-50 years) at risk, the estimated lifetime risk of schizophrenia was 1.3% in the relatives of both cases and controls. With a wider age range (15-90 years) at risk, estimated lifetime risk of schizophrenia was 2.3% for the relatives of cases and 2.2% for the relatives of controls. However, depression was significantly more common among the relatives of cases than controls.

CONCLUSIONS

Those schizophrenia-like psychoses with onset in late life are not genetically associated with schizophrenia.

The case for a psychological perspective on late-onset psychosis

OBJECTIVE

A conceptual framework is proposed for studying late-onset psychotic disorders. This incorporates developmental and psychological perspectives to complement the biological focus of most recent studies in this area.

METHOD

Studies of late-onset psychosis that focus on the specificity of neuroimaging abnormalities, family history and sensory deficits were reviewed. Aspects of the developmental and personality literature were then examined with the goal of ascertaining their relevance for the emergence of psychosis in late life. Possible future directions incorporating biological and psychological approaches are proposed.

RESULTS

The biological abnormalities identified in studies of late-onset psychosis lack the specificity to stand alone as aetiological factors. Neuroimaging changes and sensory impairment are commonly found in study subjects; however, they also occur in elderly persons without psychiatric illness as well as in those with other late-onset psychiatric disorders. Perhaps it is more appropriate to regard these changes as conferring a vulnerability to psychosis in old age, but symptoms do not develop unless other risk factors, either longstanding or ageing-related, are also present. Developmental studies of late life that have used Erikson's concept of a final lifestage crisis of achieving 'ego-integrity', suggest that personality style may be influential in determining the negotiation of this last maturational task. Failure to do so results in 'despair', fragmentation of self-image and paranoid fears. To date, there has been little investigation of the relevance of these developmental and personality factors for the emergence of psychosis in old age.

CONCLUSIONS

If we are to advance our understanding of late-onset psychotic disorders, research in this area needs to move beyond the elusive search for specific biological markers. A model of causation that integrates the longitudinal perspective of lifestage tasks with personality and biological vulnerability factors provides a broad framework which protects against premature foreclosure on aetiological determinants.

White matter signal hyperintensities in the brains of patients with late paraphrenia and the normal, community-living elderly

We determined the prevalence and anatomical location of areas of white matter hyperintensity visualized by magnetic resonance imaging in the brains of 38 late paraphrenic patients with an onset of psychotic illness after the age of 60 and 31 healthy aged community volunteers. All degrees of white matter signal hyperintensity were very common in both groups, and there was no excess of such changes in the brain of patients. Periventricular white matter and subcortical grey matter hyperintensities were significantly associated with both measured diastolic and systolic blood pressure in patients and control subjects. Periventricular and deep white matter, together with subcortical grey matter hyperintensities, were significantly associated with increased age. The excess of such presumed brain-imaging abnormalities previously reported in patients with an onset of psychosis late in life may be a consequence of earlier authors' failure to include examination of appropriate community control populations and to carefully exclude patients with evidence of stroke.

Increasing age is a risk factor for psychosis in the elderly

We examined the association between ageing and the administrative incidence rate of late onset (after age 59) non-organic, non-affective psychosis in two samples of patients aged 60 years or older who were first admitted to hospital in (1) The Netherlands between 1978 and 1992 (n = 8010) and (2) nine regional health authorities in England and Wales (n = 1777) between 1976 and 1978. There was a linear trend in the association between increasing age and first admission rates for non-organic, non-affective psychosis in the elderly, after adjustment for the possible confounding effects of time trend and gender, corresponding to an 11% increase in the incidence with each 5-year increase in age. These observations support a connection between degenerative brain processes and onset of non-affective psychosis in the elderly.

Psychotic states arising in late life (late paraphrenia). The role of risk factors

BACKGROUND

This study explored the association between 'late paraphrenia' and various risk factors such as female gender, sensory impairment, marital status, positive family history of psychoses, and the presence of abnormal neurological signs. It was hypothesised that patients would show significantly more abnormal neurological signs than controls.

METHOD

Inclusion criteria for the diagnosis of late paraphrenia were fulfilled by 47 patients, including in-patients, out-patients, day-patients, and those living in the community. Thirty-three age-, sex-, education-, and premorbid IQ-matched elderly controls were recruited from luncheon clubs in Southwark and Lambeth (London, UK). A scale for the assessment of neurological soft and hard signs was developed for this study. The Abnormal Involuntary Movement Scale (AIMS) and the Tardive Dyskinesia Rating Scale (TDRS) were also used.

RESULTS

There was a high female-to-male ratio (42:5), and a fourfold increase in the risk of patients having hearing impairment (odds ratio = 4.15, Clodds = 1.36 to 12.63). There was no difference between the two groups in visual difficulties nor in marital status. Patients were approximately ten times more likely to be living on their own (odds ratio = 10.61; Clodds = 3.59 to 31.33) and 16 times more likely to be considered socially isolated (odds ratio = 16.65; Clodds = 5.39 to 51.40). There was no difference between patients and controls in frequency of schizophrenia-like family history. Patients were more likely than controls to exhibit neurological soft signs (z = 4.70; P < 0.001; Cld = 4.61 to 9.63). The presence of abnormal involuntary and tardive dyskinesia movements was associated with the use of antipsychotic medication.

CONCLUSION

Women appear to run a greater risk of developing late paraphrenia, especially those who are socially isolated and present with associated hearing impairment. The increased presence of neurological soft signs among patients indicates that brain disease may be a critical factor in the development of psychotic symptoms in late life.

Some methodological issues in neuroradiological research in psychiatry

An outline is given of some of the methodological issues discussed in neuroradiological research on psychiatric illness. Strengths and shortcomings of magnetic resonance imaging (MRI) in depicting and quantifying brain structures are described. Temporal lobe anatomy and pathology are easily accessible to MRI, whereas limits on anatomical delineation hamper approaches to frontal lobe study. White matter hyperintense lesions are sensitively depicted by MRI, but specificity is limited. Distinction of vascular and primary degenerative dementia is considerably improved by CT and MRI analysis. Computed tomography (CT) and MRI have enhanced the understanding of treatable organic psychiatric disorders, e.g., normal pressure hydrocephalus. Subcortical and white matter pathology has been replicated in CT and MRI studies of late-onset psychiatric disorders, clinical overlap with cerebrovascular disease or neurodegeneration may be of import. Transcranial sonography findings of brainstem structural change specific to unipolar depression may contribute to the understanding of affective psychoses. Magnetic resonance spectroscopy and functional MRI are likely to stimulate psychiatric research in the future.

Quantitative magnetic resonance imaging volumetry distinguishes delusional disorder from late-onset schizophrenia

BACKGROUND

Late paraphrenia is recognised as a heterogeneous disorder. This is reflected by the division of such patients into schizophrenia and delusional disorder in ICD-10. Earlier imaging studies have suggested that major structural abnormalities may be associated with the onset of psychosis in later life.

METHOD

Fifty late paraphrenics and 35 age-matched healthy controls underwent structural magnetic resonance imaging of the whole brain in the coronal plane. Measurements were made of intracranial and brain volumes and the volumes of the intracerebral and extracerebral cerebrospinal fluid spaces.

RESULTS

No differences in intracranial, brain or extracerebral cerebrospinal fluid volumes between patients and controls were found. Late paraphrenic patients had greater lateral and third ventricle volumes than controls and the left lateral ventricle was larger than the right. When the patients were divided into appropriate ICD-10 diagnoses: paranoid schizophrenia (n = 31) and delusional disorder (n = 16), lateral ventricle volumes in the delusional disorder patients were much greater than those of the schizophrenics and almost twice those of controls.

CONCLUSIONS

Structural brain differences underly diagnostic heterogeneity within late paraphrenia. The brains of late onset schizophrenics are only subtly different from those of healthy elderly individuals.

Phenomenology, demography and diagnosis in late paraphrenia

One hundred and one patients with late paraphrenia were examined using the Present State Examination. The established high prevalence rates of female gender, the unmarried state and sensory impairment were confirmed. All of the symptoms of schizophrenia, with the exception of formal thought disorder, were found in the subjects with approximately the same prevalence as reported in schizophrenics with a symptom onset in younger life. The presence of visual hallucinosis was significantly associated with visual impairment, but the same association was not found between auditory hallucinations and deafness. Mean age at onset of symptoms was high at 74.1 years. Using ICD-10 diagnostic criteria the patients were categorized as schizophrenia (61.4%), delusional disorder (30.7%) and schizoaffective disorder (7.9%). Patients in these diagnostic categories differed in their pre-morbid IQ estimations, current cognitive state measured by the Mini-Mental State Examination and in the number of scored positive psychotic PSE symptoms and their systematization of and preoccupation with delusions and hallucinations. There were no significant differences between the patients in the ICD-10 schizophrenia and delusional disorder groups in terms of age at symptom onset, sex ratio, response to treatment, being unmarried, the presence of insight or sensory impairment. The high degree of clinical similarity between patients with late paraphrenia combined with the inability of ICD-10 to define diagnostic subgroups that correspond to patient clusters derived from clinical symptoms or which are meaningfully different from each other in terms of demographic and prognostic factors provide a strong argument for the retention of late paraphrenia as the most appropriate diagnosis for such patients.

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.

Sex and schizophrenia: effects of diagnostic stringency, and associations with and premorbid variables

In a case-record study, all first-contact patients with non-affective functional psychosis from a defined area over 20 years were diagnosed according to operational criteria of varying stringency and emphasis, and incidence rates for each set of criteria determined by sex and age at onset; data on premorbid adjustment were also analysed by sex and age at onset. The overall first-contact incidence of non-affective functional psychosis was approximately equal in men and women; however, the ratio of male to female incidence rates rose progressively when RDC (1.2), DSM-III-R (1.3), DSM-III (2.2), and Feighner (2.5) criteria for schizophrenia were applied. Schizophrenia was most common in young males and least common in older males, with females occupying an intermediate position. Schizophrenia in young males, particularly when stringently defined, was especially likely to be associated with single status, poor work and social adjustment, and premorbid personality disorder. The results suggest that schizophrenia syndrome is heterogeneous, and young males are especially prone to a severe neurodevelopmental form of illness associated with premorbid deficits.