Worldwide, the number of persons aged 65 years or older has increased from 17 million in 1900 to 342 million in 1992 and is expected to increase to 2.5 billion (comprising 20% of the total population) by 2050 1. In other words, the proportion of elderly people in this population will increase by 65%. In the next 30 years, life expectancy will increase markedly in western countries, and it is expected to increase further 2. In Egypt, there is a marked increase in the proportion of elderly people in the population; according to ‘The Statistical Year Book 2009,’ 3 people above 60 years of age constitute 6% of the Egyptian population and this proportion is expected to reach 11.5% by the year 2025 with the mean life expectancy around 70.1 years 4.
Cases of late-life psychoses are increasing markedly as the population of the world ages, and this will create a tremendous economic burden on the society because of the increasing rates of disability and institutionalization 5. It is worth mentioning that Khouzam et al.6 reported that up to 23% of the elderly population will experience psychotic symptoms that may increase the suffering of patients, family, and caregivers 5.
There is a growing awareness that late-onset psychoses constitute a heterogenous group of serious disorders of a complex nature, which present in different forms with different etiologies 7,8. These conditions include delusional disorders, induced psychotic disorders, late-onset schizophrenia, psychosis associated with dementia, mood disorders with prevailing psychotic symptoms, and others 9,10; clinicians must remember the nonspecific nature of psychotic symptoms to avoid errors in diagnosis 11. Controversy still surrounds the differential diagnosis of psychoses that begin late in life 12,13. The nosology, classification, and biological basis of psychoses in the elderly have been much debated; primary and secondary psychotic disorders of late life and their etiology are commonly considered from the view point of risk factors such as genetic predisposition triggering life events and organic cerebral dysfunction 11. In a recent study by Woolley et al.13, a total of 28.2% of patients with a neurodegenerative disease received a prior psychiatric diagnosis of a psychotic nature, as neurodegenerative diseases are often misdiagnosed as psychiatric disorders.
Late-onset schizophrenia refers to schizophrenia or a related disorder (schizoaffective, schizophreniform, or delusional disorder) with onset of prodromal symptoms after the age of 50 years 8. According to Diagnostic and Statistical Manual of Mental Disorders (DSM)-III-R, the onset of symptoms, including prodromal symptoms, must be after the age of 45 years. DSM-IV, however, does not specify the term ‘late onset,’ nor does it set an upper age limit for the diagnosis of schizophrenia 9. Although DSM-IV and DSM-IV-TR criteria do not include codeable diagnoses for late-onset schizophrenia, DSM-IV and DSM-IV-TR mention differences between cases of schizophrenia with onset after 50 years compared with those with earlier onset. Moreover, DSM-III-R included a late-onset category for patients with initial presentation at the age of 50 years or later 10.
Different studies suggest that there are specific risk factors for late-onset schizophrenia that could be identified; these include female sex, visual, auditory sensory impairments, and premorbid schizoid personality 7.
In Egypt, with the increased longevity of life and the change in family system toward a nuclear one, together with the increased medical, psychiatric, and behavioral problems in the aged population, there is a great necessity to have carefully designed plans for mental health promotion of the elderly 14. There is clearly an enormous need to clarify the clinical characteristics and range of dysfunction in cases of late-onset psychoses to streamline treatment recommendation for the already complex and vulnerable elderly population, aiming to minimize the cost of these devastating disorders through early recognition and fast intervention.
Aim of the work
The aim of the current study was to compare the sociodemographic and clinical characteristics, daily functioning, and cognitive impairment between patients with late-onset schizophrenia and those with other late-onset psychotic disorders.
Patients and methods
The study design was cross-sectional and comparative in nature, and the sample was selective. A total of 100 patients were enrolled in a 1-year period from March 2008 to February 2009; they were selected and divided into two groups, A and B, as mentioned below.
Group A comprised 50 patients fulfilling the diagnosis of schizophrenia and other psychotic disorders according to DSM-IV. We also used the operational definition according to the consensus statement by the International Late-Onset Schizophrenia Group, which stated that the term could be applied to those cases with onset of prodromal symptoms after the age of 50 years and refers to schizophrenia or a related disorder (schizoaffective, schizophreniform, or delusional disorder) 8. Both male and female patients were recruited from among the inpatients and outpatients attending the Geriatric Hospital and Institute of Psychiatry, Ain Shams University Hospitals. Some cases were also recruited from Abbasseya State Hospital because of the rarity of cases fulfilling the following inclusion and exclusion criteria: patients should have developed schizophrenia after the age of 50 years; and patients should not have a life-time history of schizophrenia, other psychoses including schizoaffective disorder, paranoid disorder, or psychotic symptoms secondary to other mental or general medical disorders or dementia.
Group B comprised 50 male and female patients fulfilling the diagnosis of late-onset nonschizophrenia psychoses developed after the age of 50 years, including psychotic disorders due to general medical conditions, mood disorders with psychotic features, and dementia with delusions and hallucinations. Patients with life-time history of schizophrenia, schizoaffective disorder, mood disorder, delirium, or late-stage dementia were excluded. Patients were recruited mainly from inpatient and outpatient clinics of Geriatric Ain Shams University Hospital.
Ethical approval of the research protocol was obtained from the Ain Shams University Ethical and Research Committee. The researchers described the study to the patients or their guardians, ensured confidentiality of information, and obtained their informed consent for participation. It was stated that participation in the study was voluntary and that they have the freedom to withdraw from the assessment at any time. Informed written consent from patients or their guardians was obtained. All 50 cases in each study group who fulfilled the research criteria and gave their consent were subjected to preliminary clinical evaluation including history of illness obtained from the patient and his or her family. Physical and neurological examinations were conducted by a Gerontologist Specialist. The research team also revised the medical files and investigations of all patients.
Tools and procedures
All patients underwent the following examinations: (a) clinical assessment, (b) assessment of daily functioning, (c) cognitive assessments, and (d) Fahmy and El-Sherbini’s Social Classification Scale.
Clinical assessments included the Structured Clinical Interview for DSM Axis-I diagnosis – clinical version 15 and the Positive and Negative Syndrome Scale (PANSS) 16. The PANSS was designed to measure the severity of psychopathology in adult patients with schizophrenia, schizoaffective disorder, and other psychotic disorders.
Assessment of daily functioning included activities of daily living (ADL) and instrumental activities of daily living (IADL).
The ADL scale 17 assesses certain basic abilities that a person must possess to remain at home independently. These abilities allow a person to perform basic self-care tasks. Accordingly, patients were classified into the following groups: needs no support (10), needs partial support (six to nine), or needs full support (zero to five). The Arabic standardized version was used 18. The IADL scale 17 measures two broad categories: (a) basic self-maintenance behaviors such as feeding, dressing, bathing, and mobility, and (b) more complex behaviors such as managing finances, traveling, and taking medications. These abilities are higher-level abilities that allow a person to function independently at home or in the community. Accordingly, patients were classified into the following groups: needs no support (10), needs partial support (six to nine), or needs full support (zero to five). We used the Arabic standardized version 18.
Cognitive assessments included Cambridge Mental Disorders of the Elderly Examination (CAMDEX) scale 19 and the Wechsler Adult Intelligence Scale (WAIS).
The CAMDEX scale 19 was developed to assess the diagnosis and measurement of dementia among the elderly. This scale assessed orientation, language (expression, comprehension), memory (both recent and remote), and learning praxis, attention, abstract thinking, perception, and calculation. It was translated into Arabic and validated by Mahmoud et al.20. The WAIS 21 is the most commonly administered general intelligence test for adults, and it is also viewed as a broad assessment of cognitive functions. The Wechsler scale provides information about the important aspects of the patients’ intellectual functioning. We used the standardized Arabic version of the test 22.
Fahmy and El-Sherbini’s Social Classification Scale 23 is based on parameters such as education and work of the father, education and work of the mother, income crowding index, and sanitation.
Data were statistically analyzed using the Statistical Package for Social Sciences program software version 17.0. (SPSS Inc., Illinois, Chicago) Descriptive statistics were obtained for numerical parametric data as means and SD and for categorical data as number and percentage. Inferential analyses were performed for quantitative variables using Student’s t-test for independent data. Qualitative data were analyzed using Pearson’s χ2-test. The level of significance was taken at P-value less than 0.05; otherwise, it was considered nonsignificant.
To fulfill the aim of the work, we compared the studied groups with each other with regard to their sociodemographic characteristics, clinical data, ADL, and cognitive functioning.
Patients in group A were significantly younger (mean age 69.5±3.39) – they were mainly women (72%), the majority were never married (54%), and 62% were living alone – compared with group B (mean age 72.5±2.26), who were mainly married (46%) and lived more often with their families. Social class did not show any statistical differences between the groups.
A total of 54% of group A patients graduated from secondary schools and universities compared with only 38% of group B patients. Previous engagement in different occupations showed striking differences, as a higher percentage of group B patients were engaged in jobs previously compared with group A patients (P=0.000). Details are illustrated in Table 1.
Age at onset, duration of illness, and family history of psychiatric illness
Patients in group A developed their illness significantly earlier (P=0.001) and had longer duration of illness than did patients in group B. Although group A patients had higher frequency of positive family history of psychiatric disorders compared with group B patients (8 and 4%, respectively), the difference was not statistically significant (P>0.05) (Table 1).
Group A patients had significantly (P=0.000) more chest diseases (72%), auditory impairment (30%), and musculoskeletal problems (66%) compared with group B patients; in contrast, group B patients had significantly (P=0.000) more renal (56%) and neurological diseases (50%) than group A patients. No statistically significant difference was found between the two groups with regard to diabetes mellitus, hypertension, cardiac diseases, and visual impairment (Table 2).
Data represented in Fig. 1a show that, among patients with late-onset schizophrenia, 70% had paranoid subtype, 12% had delusional disorder, and the remaining had either undifferentiated or schizoaffective subtype. In contrast, 70% of group B patients with other late-onset psychoses had psychotic symptoms due to dementia, 20% had mood disorder with psychotic symptoms, and the remaining 10% had psychosis secondary to medical illnesses (Fig. 1b).
Assessment of psychotic symptoms using Positive and Negative Syndrome Scale
Figure 2 illustrates clearly that group B patients had significantly lower scores on items assessing positive symptoms (including delusions, conceptual disorganization, and hallucinatory behavior) and higher scores on general psychopathology (including somatic concern, anxiety, guilt feelings) than did group A patients; the scores on negative symptoms (including blunted affect, emotional withdrawal, poor rapport) and the total PANSS scores were almost similar in both groups and did not show any significant differences.
The nature and content of delusions differ from that of group A patients who had more complex bizarre delusions of control, passivity, and persecution in comparison with group B patients with dementia who exhibited simple paranoid delusion and also delusions of someone stealing or hiding objects. Group B patients with depression described somatic, hypochondriacal delusions. In addition, some patients had delusions of guilt and nihilism, and others had noncongruent delusions of persecution and reference.
The pattern of hallucinations in group A patients showed multimodal hallucinations, mainly auditory, tactile, and olfactory hallucinations. Schneiderian first-rank symptoms such as hearing multiple voices or running commentary were recorded in this group, whereas group B patients with dementia had mainly visual hallucination. Group B patients with mood disorder had auditory and olfactory hallucinations.
Functional assessment of the ADL scores revealed that group A patients had significantly better ADL and IADL scores, whereas a significant number of group B patients needed partial and complete support compared with group A patients (Table 3).
Using section B (CAMCOG) of the CAMDEX it was revealed that group A patients scored almost within norms, except for memory, apraxia, abstract, and perception items, compared with group B patients who scored lower in all cognitive items. Group A patients compared with group B showed highly statistically significant differences in the following parameters: language, memory, abstract, and perception (P=0.000). Their scores on orientation, attention, and apraxia were significantly lower at the following levels of significance: 0.004, 0.02, and 0.001, respectively (Table 4).
On the WAIS, patients with late-onset schizophrenia scored significantly better in all total and subitems of the test. It was noticed that a very highly statistically significant difference exists between both groups with regard to total, performance, and verbal intelligence quotient scores, being lower in group B than in group A. Both groups showed discrepancy between verbal and performance intelligence quotient, which denotes cognitive decline (Table 5).
Psychotic manifestations constitute an important problem in the geriatric population. Some authors have reported that psychosis was present in 26% of elderly patients admitted to an inpatient geriatric unit and in 36% of patients admitted for the first time to a psychiatric facility 24. Within the psychiatric ward, cases showing an onset after 40 years of age comprised 10.8% of the total population 25. Early detection and management of psychotic symptoms is associated with a better psychosocial adjustment 24.
This study aimed to uncover some clinical aspects in a sample of the Egyptian elderly population. The research aimed to study a group of elderly patients with primary psychotic disorders that appear for the first time after the age of 50 years (group A), including schizophrenia, delusional disorder, and schizoaffective disorders, and compare them with a group of elderly patients with psychotic disorders other than schizophrenia (group B), which include psychosis associated with dementia, mood disorders, and psychosis secondary to medical conditions.
Late-onset schizophrenia affects women two to 10 times more than it does men 8,10. With regard to sex, 72% of patients with late-onset schizophrenia were significantly predominantly women compared with only 52% of patients with late-onset other psychoses. This result was in accordance with a previous study by Howard et al.8. In the Egyptian community, Ashour et al.26 found that the ratio between men and women was 1 : 3 among the elderly with different psychiatric morbidities in Cairo hostels. The preponderance of female patients in the group of late-onset schizophrenia was also recorded previously by Haiba 27, who studied paranoid symptoms in the elderly population in Egypt. Recently in China, Yasuda and Kato 25 found that female patients comprised 16.3%, which was significantly higher than that of male cases (2.0%). The robustness of this finding, coupled with the higher incidence rates of early-onset schizophrenia in men, led to the estrogen hypothesis, which postulates that estradiol has antidopaminergic properties that somehow protect women to a certain degree from puberty to menopause. As estradiol levels decrease at midlife, this protective factor is lost, thus predisposing vulnerable women to a second illness-onset peak after the age of 45 years because of the decline in estrogen with relative excess of dopamine D2 receptors 28.
Social isolation has been linked to late-onset schizophrenia; it either plays a role in causation or may be the consequence 29. In our research, we found that patients with late-onset schizophrenia were predominantly never married or were divorced; a significant proportion of them were living alone compared with the group of nonschizophrenia late-onset psychosis patients. Our results agreed with those of previous national and international researchers who found that social isolation, living alone, having no friends, and having no regular visitors are associated with late-onset schizophrenia 27,29,30.
Genetic factors seem to play a smaller role in the etiology of late-onset schizophrenia 8. Our results showed that there were no significant differences with regard to family history of psychiatric disorders among both studied groups, consolidating the above-mentioned findings.
Late-life psychotic symptoms often have a medical etiology and may be the first symptoms of undiagnosed medical conditions. This is because elderly people usually take several medications with possible side effects and drug interactions, which may contribute to the appearance of psychotic symptoms 6,7.
Group B patients had significantly more frequent renal and neurological diseases. It was also reported in Egyptian communities that cognitive and behavioral changes were frequently encountered in elderly patients with renal impairment 31. In addition, Mostafa et al.32 had reported a high prevalence of neurological incidents among elderly patients presenting with psychiatric symptoms.
Group A patients with late-onset schizophrenia compared with their group B counterparts had significantly more frequent chest diseases, probably because of excessive smoking, more musculoskeletal problems, and auditory impairment, which add to their social isolation. We are in agreement with previous studies that found that some evidence exists of an association between sensory deficits and psychotic symptoms 33,34; moreover, some have suggested that late-onset schizophrenia might reflect the impact of sensory deprivation due to uncorrected visual and hearing deficits associated with aging 35.
The majority of group B patients (70%) had psychosis due to dementia, whereas 20% had mood disorder with psychotic features, and 10% had psychosis secondary to medical illnesses. Our results are not in agreement with the study by Barclay and Almeida 36, who reported that the most frequent clinical diagnoses for elderly patients with psychotic symptoms other than schizophrenia were dementia (40%), depression (33%), psychosis secondary to a medical condition (7%), bipolar disorder (5%), and the remaining due to adverse reaction to medication. Jeste and Finkel 37 stated that the incidence of psychosis in dementia was 30–50%, whereas Paulsen et al.38 reported that approximately 50% of dementia patients will have psychotic symptoms, predominantly delusions and hallucinations. The difference between our results and the above-mentioned findings could be attributed to the difference in sampling methods and techniques.
The diagnosis of paranoid disorder was by far the most diagnostic type of schizophrenia encountered in our late-onset schizophrenia group (70%), whereas only 12% had delusional disorder and 14% had schizoaffective disorder. Only 4% had undifferentiated schizophrenia. In their study, Yasuda and Kato 25 found that the paranoid type comprised 55.3% of the total population of late-onset cases. The higher prevalence of paranoid schizophrenia in our sample compared with other studies could not be interpreted because our sample is a selective sample rather than a random one.
Symptoms of psychosis associated with late-onset schizophrenia were different from that of other late-onset psychoses. Delusions reported in dementia patients were typically simple, nonbizarre, and of the paranoid type, for example, morbid jealousy and delusions related to someone stealing or hiding objects. A number of researchers have found that delusions and hallucinations are commonly associated with aggression, agitation, and disruptive behavior in patients with dementia 39–41. Patients with late-onset schizophrenia tended to have complex bizarre systematized delusions, example persecutory delusions and suffering from a disease or spouse infidelity. Delusions in patients with mood disorders were characterized by somatic, hypochondriacal, guilty, or nihilistic delusions, and also by noncongruent delusions such as persecution and reference. These results were similar to previous findings in the elderly Egyptian population 42–44. From the clinical point of view, Alexopoulos et al.45 stated that depressive delusions can be distinguished from delusions in patients with dementia, in that the latter are less systematized and less congruent to the affective disturbance.
Controversy surrounds the differential diagnosis of hallucinations that begin late in life 40,46. In our study, we reported that hallucinations in dementia were more frequently visual than auditory; the reverse is true for patients with schizophrenia who had multimodal hallucinations. Patients with psychotic symptoms associated with depression had mainly auditory and olfactory hallucinations.
The severity of positive, negative, and general psychopathologic symptoms was measured with the respective subscales of PANSS. Data revealed that patients with late-onset schizophrenia had more severe positive symptoms and less severe general psychopathology in contrast to patients who had nonschizophrenia psychoses. Cohen et al.39 stated that negative symptoms can be difficult to distinguish from the confounding effects of depression, medications, and institutionalization. In our study, using the PANSS, it was evident that scores of negative symptoms were similar in both groups studied and were far lower than scores on positive symptom scales; these results are in accordance with those of the San Diego study, which proved that lower scores on negative symptoms tended to be associated with the higher age group having psychotic illness 40.
Assessment of daily functioning
Assessment of daily functioning revealed that patients with late-onset schizophrenia had significantly better ADL and IADL scores, whereas a significant number of patients with late-onset nonschizophrenia psychoses needed partial and complete support. This finding may be attributed to the medical conditions of the latter group, who had more frequent medical, neurological, and cognitive impairment, which negatively impacted their ability to perform daily activities compared with those who suffered from late-onset schizophrenia. The deteriorated daily functioning reflects the devastating effects of dementia on ADL and highlights the impact of this disability on caregivers. These findings were in accordance with those of previous studies, which found that higher levels of daily functioning among elderly people with schizophrenia were associated with better cognitive functioning, fewer negative symptoms, better physical health, and independent living in the community 47–49.
Patients with a primary diagnosis of dementia suffer from a number of psychotic symptoms, and patients with primary functional disorders become cognitively impaired. Barclay and Almeida 36 stated that schizophrenia does not increase the risk of dementia. In contrast, individuals with cognitive impairment in later life are at increased risk for psychosis. Dementia is characterized by a progressive decline in cognitive abilities. This was true in our research, which illustrated that group B patients, in which 70% of patients had a diagnosis of dementia, scored significantly worse in all subitems of cognitive assessment according to CAMCOG compared with group A patients. It is interesting to note that several groups of investigators have reported potentially relevant clinical, neuropsychological, and neurobiological differences between dementia patients with and without psychosis. Stern et al.50 observed that, among dementia patients, psychosis was associated with a greater prevalence of rapid cognitive decline. Moreover, in a study by Jeste and Finkels 37, it was noted that those with psychosis had greater impairment on putative neuropsychological tests of frontal lobe function compared with dementia patients without psychosis.
The association between cognitive functions in dementia cases with or without psychosis should be clarified in future studies. There was much debate on this topic; Linda et al.51 reported that behavioral symptoms and cognitive functions are independent dimensions, whereas Hopkins and Libon 52 suggested a strong relationship between severity of psychosis and poor performance on some cognitive functions.
From the current research, the obtained results are important in demonstrating that the cognitive deficits associated with late-onset schizophrenia are different from the cognitive declines associated with dementia. The rate of decline observed among the dementia groups in the present sample appears to be consistent with that reported in the literature 53,54. Thus, the onset of schizophrenia late in life does not appear to be a mere by-product of a dementia disorder. The same conclusion is consistent with the findings from studies by the Mount Sinai research group, which examined chronically institutionalized elderly schizophrenia patients. These investigators found that the pattern of cognitive deficits of such patients was distinct from that associated with dementia; moreover, their postmortem neuropathological studies indicated that the prevalence of amyloid plaques and neurofibrillary tangles was not different from that of age-matched healthy control individuals 55. Unfortunately, in this study, we did not compare group A patients with healthy controls; thus, we could not comment on cognitive decline in the late-onset schizophrenia group in comparison with the healthy elderly population.
Patients with late-onset schizophrenia compared with patients with other late-onset psychoses differ in a number of psychosocial and clinical variables, daily functioning, and cognitive abilities. The results of this study contribute to the development of a better understanding of the elderly patient population with different types of late-onset psychoses, which have been largely ignored in research. These findings draw the attention of policymakers and psychiatrists to the burden of psychotic disorders in the elderly and the need for specialized psychiatric care units providing intensified help and rehabilitation.
In Egypt, research in the area of old-age psychosis is still scarce and has been neglected. Thus, studies on this topic on a large representative sample from different geographical areas are highly recommended. In addition, prospective cohort studies of elders with psychotic disorders to determine the outcome of psychotic disorders are mandatory. Studies addressing clarification of risk factors to develop psychosis at later age, the impact of psychotic symptoms on caregivers, and treatment outcome of old-age psychosis are recommended. Future studies should involve different disciplines. These disciplines should cooperate together to provide evidence-based data that can inform the public, help policymakers to make informed decisions and plans, and stimulate further research.
Strength and limitations of the study
One of the strengths of this study is that (according to best of our knowledge) it is among the first studies to compare late-onset schizophrenia with nonschizophrenia late-onset psychoses. Although our findings shed light on this poorly understood and investigated area of research, the results should be considered preliminary data because of the limitations of small size and type of sample, which was a selective rather than a stratified random sample representing different geographical areas in Egypt. Our findings must be reviewed as provisional and will be subjected to revision, as more studies are needed in the field of elderly patients with psychotic disorders.
The authors express their gratitude to Professor M. El Banouby, former chair of the department of Geriatric Medicine, Ain Shams University, for his support and guidance. The authors are grateful to Dr Hisham Sadek, Dr Ahmed El Missiry, Dr Abeer Mahmoud, Dr Hanan Hussein, Dr Ahmed El Shafie, and the other research participants from the department of Neuropsychiatry, Ain Shams University, for their time, training on tools, guidance, advice, and efforts in completing the study assessment. The authors would also like to thank Dr Olfat Kahla, senior psychologist in Geriatric Hospital, Ain Shams University, for her help, and Dr Mohamed Hassan Taha from ‘TIT Solution’ for the statistical analysis.
Conflicts of interests
There are no conflicts of interest.
1. Olshansky SJ, Carnes BA, Cassel CK. The aging of the human species. Sci Am. 1993;268:46–52
2. Spar JE, La Rue A Anxiety disorders and late onset schizophrenia. In: Spar JE, La Rue A, editors. Clinical manual of geriatric psychiatry. 1st ed. American Psychiatric Publishing; 2006. p. 302–306
4. El Banouby MHRobinson M, Novelli W, Pearson C, Norris L. Health and aging in the Eastern Mediterranean region. Global health and global aging. 2007 USA The AARP Foundation:215–226
5. Morris SK, Jeste DVHazzard WR, Blass JP, Ettinger WH, Halter JB, Ouslader JG, Ouslander JG. Schizophrenia and other psychotic disorders. Principles of geriatric medicine and gerontology. 19984th ed New York Mcgraw-Hill:1341–1349
6. Khouzam HR, Battista MA, Emes R, Ahles S. Psychoses in late life: evaluation and management of disorders seen in primary care. Geriatrics. 2005;60:26–33
7. Harris MJ, Jeste DV. Late-onset schizophrenia
: an overview. Schizophr Bull. 1988;14:39–55
8. Howard R, Rabins PV, Seeman MV, Jeste DV. Late-onset schizophrenia
and very-late-onset schizophrenia
-like psychosis: an international consensus. The International Late-Onset Schizophrenia
Group. Am J Psychiatry. 2000;157:172–178
9. McClure FS, Gladsjo JA, Jeste DV. Late-onset psychosis: clinical, research and ethical considerations. Am J Psychiatry. 1999;156:935–940
10. Jeste DV, Dolder CR, Nayak GV, Salzman C. Atypical antipsychotics in elderly patients with dementia or schizophrenia: review of recent literature. Harv Rev Psychiatry. 2005;13:340–351
11. Fuchs T. Life events in late paraphrenia and depression. Psychopathology. 1999;32:60–69
12. Rabins PV, Lavrisha M. Long-term follow-up and phenomenologic differences distinguish among late-onset schizophrenia
, late-life depression and progressive dementia. Am J Geriatr Psychiatry. 2003;11:589–594
13. Woolley JD, Khan BK, Murthy NK, Miller BL, Rankin KP. The diagnostic challenge of psychiatric symptoms in neurodegenerative disease: rates of and risk factors for prior psychiatric diagnosis in patients with early neurodegenerative disease. J Clin Psychiatry. 2011;72:126–133
14. Omar AN, Haroun A, Nagy NE. Prevalence of depressive symptoms in physically-ill elderly inpatients. Curr Psychiatry. 1998;5:145–155
15. First MB, Gibbon M, Spitzer RL, Williams JBW, Benjamin LS Structured clinical interview for DSM-IV axis II personality disorders, (SCID-II). 1997 Washington, DC American Psychiatric Press, Inc
16. Kay SR. Positive-negative symptom assessment in schizophrenia: psychometric issues and scale comparison. Psychiatr Q. 1990;61:163–178
17. Lawton MP, Brody EM. Assessment of older people: self-maintaining and instrumental activities of daily living
. Gerontologist. 1969;9:179–186
18. El Okl MA Prevalence of alzheimer’s disease and other types of dementia in the Egyptian Elderly. Faculty of Medicine, Ain Shams University; 2002
19. Kojo K. Late-onset schizophrenic syndromes in socially isolated situations: a comparison of Janzarik’s ‘Kontaktmangelparanoid’ and late paraphrenia. Psychogeriatrics. 2010;10:83–89
20. Mahmoud A Clinical profile of patients attending memory clinic in Ain Shams University, Institute of Psychiatry. Ain Shams University; 2002
21. Wechsler D Wechsler adult intelligence scale-revised. 1981 San Antonio, TX The Psychological Corporation
22. Melika LK The Wechsler Adult Intelligence scale. 1996 Dar El Nahda El Arabia, Egypt
23. El Sherbini FM The Egyptian classification of social class. Egypt: Faculty of Medicine, Tanta University; 1986
24. Girard C, Simard M. Clinical characterization of late- and very late-onset first psychotic episode in psychiatric inpatients. Am J Geriatr Psychiatry. 2008;16:478–487
25. Yasuda M, Kato S. Clinical psychopathological research on late-onset schizophrenia
– mainly patients with schizophrenia from a hospital psychiatric ward. Seishin Shinkeigaku Zasshi. 2009;111:250–271
26. Ashour A, Okasha A, Sadek A, Hambali M, Lotaief F, Bishry Z. Portrait of old people in Cairo hostels. Egypt J Psychiatry. 1982;5:75–94
27. Haiba AAM A community study of paranoid symptoms in the elderly population. Faculty of Medicine, Tanta University; 2002
28. Lehmann SW. Psychiatric disorders in older women. Int Rev Psychiatry. 2003;15:269–279
29. Riecher Rossler A, Rossler W, Forstl H, Meise U. Late-onset schizophrenia
and late paraphrenia. Schizophr Bull. 1995;21:345–354 discussion 355–356
30. Cohen CI, Vahia I, Reyes P, Diwan S, Bankole AO, Palekar N, et al. Schizophrenia in later life: clinical symptoms and social well-being. Psychiatr Serv. 2008;59:232–234
31. El Said SMS Study of the effect of renal impairment on cognitive function in elderly patients. Faculty of Medicine, Tanta University; 2004
32. Mostafa MM, Akram A. Clinical deterioration in vascular dementia: role of new ischemic lesions, hypoalbuminemia and hyponatremia. Egypt J Neurol Psychiat Neurosurg. 2004;41:401–412
33. Prager S, Jeste DV. Sensory impairment in late-life schizophrenia. Schizophr Bull. 1993;19:755–772
34. Howard R, Cox T, Almeida O, Mullen R, Graves P, Reveley A, et al. White matter signal hyperintensities in the brains of patients with late paraphrenia and the normal, community-living elderly. Biol Psychiatry. 1995;38:86–91
35. Almeida OP, Howard RJ, Levy R, David AS. Psychotic states arising in late life (late paraphrenia) psychopathology and nosology. Br J Psychiatry. 1995;166:205–214
36. Barclay L, Almeida O. Schizophrenia in later life. Curr Opin Psychiatry. 2000;13:423–427
37. Jeste DV, Finkel SI. Psychosis of Alzheimer’s disease and related dementias. Diagnostic criteria for a distinct syndrome. Am J Geriatr Psychiatry. 2000;8:29–34
38. Paulsen JS, Salmon DP, Thal LJ, Romero R, Weisstein Jenkins C, Galasko D, et al. Incidence of and risk factors for hallucinations and delusions in patients with probable AD. Neurology. 2000;54:1965–1971
39. Cohen CI Schizophrenia into later life: Treatment, research and policy. Library of Congress: American Psychiatric Publishing Inc.; 2003
40. Jeste DV, Twamley EW, Eyler Zorrilla LT, Golshan S, Patterson TL, Palmer BW. Aging and outcome in schizophrenia. Acta PsychiatrScand. 2003;107:336–343
41. Quin RC, Clare L, Ryan P, Jackson M. ‘Not of this world’: the subjective experience of late-onset psychosis. Aging Ment Health. 2009;13:779–787
42. Metwally AS Prevalence of depression among Egyptian geriatric community. Faculty of Medicine, Ain Shams University; 1998
43. El Banoty M, Ghanem M, Mortagy A, Metwally A, El Nahas A, Sayed M. Prevalence of depression among the aged Egyptian community. Curr Psychiatry. 1999;6:3
44. Asaad T. Recognizing depression in patients with dementia (a comparative study between Alzheimer's disease and vascular dementia in a sample of Egyptian patients). CurrPsychiatry. 2002;9:72–73
45. Alexopoulos GS, Meyers BS, Young RC, Kalayam B, Kakuma T, Gabrielle M, et al. Executive dysfunction and long-term outcomes of geriatric depression. Arch Gen Psychiatry. 2000;57:285–290
46. Vahia I, Bankole AO, Reyes P, Diwan S, Palekar N, Sapra M, et al. Schizophrenia in later life. Aging Health. 2007;3:383–396
47. Gupta S, Steinmeyer C, Frank B, Lockwood K, Lentz B, Schultz K. Older patients with schizophrenia: nature of dwelling status and symptom severity. Am J Psychiatry. 2003;160:383–384
48. Evans JD, Heaton RK, Paulsen JS, Palmer BW, Patterson T, Jeste DV. The relationship of neuropsychological abilities to specific domains of functional capacity in older schizophrenia patients. Biol Psychiatry. 2003;53:422–430
49. Viertiö S, Tuulio Henriksson A, Perälä J, Saarni SI, Koskinen S, Sihvonen M, et al. Activities of daily living
, social functioning and their determinants in persons with psychotic disorder. Eur Psychiatry. 2011 [In Press]
50. Stern Y, Albert M, Brandt J, Jacobs DM, Tang MX, Marder K, et al. Utility of extrapyramidal signs and psychosis as predictors of cognitive and functional decline, nursing home admission and death in Alzheimer’s disease: prospective analyses from the Predictors Study. Neurology. 1994;44:2300–2307
51. Linda CW, Nelson LS, Sl M, Victor WC, Agnes SY, Leung PY, et al. Apolipoprotein epsilon-4 allele and the two-year progression of cognitive function in Chinese subjects with late-onset Alzheimer's disease. Am J Alzheimer Dis Other Demen. 2006;21:92–9
52. Hopkins MW, Libon DJ. Neuropsychological functioning of dementia patients with psychosis. Arch Clin Neuropsychol. 2005;20:771–783
53. Clarke R, Smith AD, Jobst KA, Refsum H, Sutton L, Ueland PM. Folate, vitamin B12 and serum total homocysteine levels in confirmed Alzheimer disease. Arch Neurol. 1998;55:1449–1455
54. Galasko DR, Gould RL, Abramson IS, Salmon DP. Measuring cognitive change in a cohort of patients with Alzheimer’s disease. Stat Med. 2000;19:1421–1432
55. Palmer BW, Heaton RK, Gladsjo JA, Evans JD, Patterson TL, Golshan S, et al. Heterogeneity in functional status among older outpatients with schizophrenia: employment history, living situation and driving. SchizophrRes. 2002;55:205–215