Higher rates of cigarette smoking in male adolescents before the onset of schizophrenia: a historical-prospective cohort study

OBJECTIVE: The prevalence of cigarette smoking among schizophrenia patients is significantly higher than in the general population; this may reflect self-medication of symptoms and/or adverse effects of neuroleptics. The authors examined the prevalence of cigarette smoking in apparently healthy adolescents later hospitalized for schizophrenia. METHOD: Each year, a random sample of male Israeli military recruits, who have been screened and found not to be suffering from major psychopathology, complete a smoking questionnaire. Through the Israeli National Psychiatric Hospitalization Case Registry, 14,248 of these adolescents were followed to determine later psychiatric hospitalization. RESULTS: Of the 14,248 adolescents assessed, 4,052 (28.4%) reported smoking at least one cigarette a day. Over a 4-16-year follow-up, the prevalence of schizophrenia in the entire cohort was 0.3% (N=44). Smokers were at greater risk for later schizophrenia; the adjusted relative risk was 1.94, and the 95% confidence interval (CI) was 1.05-3.58. The number of cigarettes smoked was significantly associated with the risk for schizophrenia. Compared to nonsmokers, adolescents who smoked 1-9 cigarettes/day were 1.38 times (95% CI=0.48-4.00) as likely to be hospitalized later for schizophrenia, and adolescents who smoked 10 cigarettes/day or more were 2.28 times (95% CI=1.19-4.34) as likely; the latter difference was statistically significant. CONCLUSIONS: Taken together with the existing data on abnormalities in nicotinic transmission in patients and their relatives, this higher prevalence of smoking in future schizophrenia patients, before the onset of their illness, might indicate that impaired nicotinic neurotransmission is involved in the pathophysiology of schizophrenia.     

Dysthymia in male adolescents is associated with increased risk of later hospitalization for psychotic disorders: a historical-prospective cohort study

Aim: Retrospective studies indicate that patients with psychotic disorders and schizophrenia often suffer from depressive symptoms before the onset of psychosis. In a historical‐prospective design, we studied the association between dysthymia in adolescence and later hospitalization for psychotic disorders and schizophrenia. Methods: The Israeli Draft Board screens the entire, unselected population of 16–17 years old male adolescents for psychiatric disorders. These adolescents were followed for hospitalization for psychotic disorders and schizophrenia using the Israeli National Psychiatric Hospitalization Case Registry. Of 275 705 male adolescents screened, 1267 (0.5%) were hospitalized for psychotic disorders (International Classification of Diseases [ICD]‐10 20.0–29.9), and 757 (0.3%) were hospitalized for schizophrenia (ICD‐10 20.0–20.9) over the next 1–10 years. Results: Of 275 705 male adolescents screened, 513 (0.2%) were diagnosed as suffering from dysthymia by the Draft Board. Of these adolescents, 10/513 (2.0%) were later hospitalized for psychotic disorders (including schizophrenia, HR = 3.967, 95%CI (confidence intervals): 2.129–7.390), and 4/513 (0.8%) were later hospitalized for schizophrenia (HR = 2.664, 95%CI: 0.997–7.116). Conclusions: In this population‐based cohort of male adolescents, dysthymia was associated with increased risk for future psychotic disorders. Dysthymia in some adolescents might be a prodromal symptom, while in others it might be a risk factor for later psychosis. Clinicians assessing dysthymic adolescents should be aware that these symptoms might be part of the prodrome.     

Association between nonpsychotic psychiatric diagnoses in adolescent males and subsequent onset of schizophrenia

BACKGROUND: Nonpsychotic psychiatric symptoms may occasionally herald the later development of schizophrenia. This study followed a population-based cohort of adolescents with nonpsychotic, non-major affective psychiatric disorders to ascertain future hospitalization for schizophrenia. METHODS: Results of the medical and mental health assessments on 124 24416- to 17-year-old males screened by the Israeli draft board were cross-linked with the National Psychiatric Hospitalization case registry, which contains data on all psychiatric hospitalizations in the country, during a 4- to 8-year-long follow-up through age 25 years. In the cohort, 9365 adolescents were assigned a nonpsychotic, non-major affective diagnosis by the draft board. RESULTS: After excluding 167 adolescents who were hospitalized before or up to 1 year after the draft board assessment, 1.03% of the adolescents assigned a nonpsychotic, non-major affective psychiatric diagnosis, compared with only 0.23% of the adolescents without any psychiatric diagnosis, were later hospitalized for schizophrenia. Of the patients with schizophrenia, 26.8%, compared with only 7.4% in the general population, had been assigned a nonpsychotic, non-major affective psychiatric diagnosis in adolescence (overall odds ratio [OR], 4.5; 95% confidence interval [CI], 3.6-5.6), ranging from OR, 21.5 (95% CI, 12.6-36.6) for schizophrenia spectrum personality disorders to OR, 3.6 (95% CI, 2.1-6.2) for neurosis. CONCLUSION: These results reflect the relatively common finding of impaired functioning in patients later hospitalized for schizophrenia and the relatively low power of these disorders in predicting schizophrenia.     

The relationship between risk of hospitalization for schizophrenia, SES, and cognitive functioning

Although most studies find low socioeconomic status (SES) to be associated with prevalence of schizophrenia, incidence studies do not generally support this, and some even report an inverse association. The objective of the current historical prospective study was to examine the relationship between SES, cognitive functioning, and risk of hospitalization for schizophrenia in a population-based sample of Israeli adolescents. Subjects were 811 487 adolescents, assessed by the Israeli military draft board for socio-demographic factors and cognitive functioning. Data on later hospitalization for schizophrenia were obtained from a population-based hospitalization registry. Findings indicated that when simply examining SES and schizophrenia, lower SES was associated with greater risk of hospitalization for schizophrenia (Hazard Ratio [HR] = 1.193, 95% CI = 1.091-1.303). When dividing the cohort into low, average, and high cognitive functioning, SES did not influence the risk for schizophrenia among individuals with high and average cognitive functioning, whereas among individuals with low cognitive functioning, high SES was found to slightly increase the risk for schizophrenia (HR = 1.21, 95% CI = 1.03-1.42). One possible explanation for this finding might be that among individuals from low socioeconomic backgrounds, low IQ may reflect decreased opportunities related to SES, whereas among individuals from high SES backgrounds, low IQ might reflect risk for later psychopathology.     

Impaired reading comprehension and mathematical abilities in male adolescents with average or above general intellectual abilities are associated with comorbid and future psychopathology

Research indicates that persons with learning disorders often suffer from psychopathology. We assessed current and future psychopathology in male adolescents with discrete impairments in reading comprehension (IRC) or arithmetic abilities (IAA) but with average or above-average general intellectual abilities. Subjects were a population-based cohort of 174,994 male adolescents screened by the Israeli Draft Board with average or above-average intellectual abilities but with low scores (8.6th and 10th lowest percentile respectively) on reading or arithmetic tests. They were compared with adolescents who scored in the 10th percentile and above on these tests (comparison group). Relative to the comparison group, male adolescents with IRC, IAA, or IRC and IAA (0.69%), had poorer scores on most behavioral assessments and higher prevalence of current psychopathology: 4.2% (comparison group), 8.0% (IRC), 7.0% (IAA), and 9.8% (IRC and IAA). Adolescents with IRC were also at increased risk for later hospitalization for schizophrenia (hazard ratios = 1.8, 95% confidence interval: 1.3-2.6). Male adolescents with average and above-average general intellectual abilities but with IRC or IAA are more likely to have current and future psychopathology. Impairments in intellectual functioning and abnormal behaviors leading to mental illnesses may share common neurobiological substrates. The results support screening male adolescents with learning disorders for psychopathology.     

Geographical analysis of the risk of psychiatric hospitalization in Hamburg from 1988 – 1994

The analysis of the geographical distribution of hospital cases is obviously important for the purpose of planning hospital services, but it is of even greater significance in the planning of psychiatric services. This concern motivated our seven-year-long study, which examined hospitalization risks among various categories of psychiatric disorders in the major German city of Hamburg. Our database encompassed 77% (n = 64,000) of all psychiatric admissions in a total of 41 hospitals, most of which are general hospitals. In order to carry out the geographical analysis we employed a new statistical method based on a mixture distribution model. According to our findings, the strongest indications of an increased frequency were among male cases of schizophrenia, drug abuse and organic psychoses, and female cases of neurotic disorders, personality disorders, drug abuse and schizophrenia. We found that some areas are exposed to a risk of hospitalization for these diagnostic categories which is more than 50% above the reference. Contrary to other authors we did not identify an increased frequency of admission concentrated in the inner-city area for any of the diagnostic groups. The risk of hospitalization for schizophrenics was almost entirely associated with the close proximity of psychiatric units, while the risks for neuroses and personality disorders, as well as alcohol and drug abuse, appeared to be concentrated in areas of low social status. However, a statistically relevant correlation between an increased risk of hospitalization and low social status could be determined only for drug abuse and alcoholism. In the end, we did identify two areas in which there was an increased risk of hospitalization for several diagnostic groups, and this information will undoubtedly facilitate the planning of hospital and psychiatric services. The fact that our findings deviate to some extent from other authors - especially with respect to neuroses and personality disorders, but also to addiction - can be attributed to the inclusion of psychiatric cases from general hospitals in our geographic analysis.     

Major mental disorders and criminal violence in a Danish birth cohort

BACKGROUND: This epidemiological investigation was designed to examine the relationships between each of the major mental disorders and criminal violence. Specifically, we assessed whether a significant relationship exists between violence and hospitalization for a major mental disorder, and whether this relationship differs for schizophrenia, affective psychoses, and organic brain syndromes. METHODS: Subjects were drawn from a birth cohort of all individuals born between January 1, 1944, and December 31, 1947, in Denmark (N = 358 180). Because of the existence of accurate and complete national registers, data were available on all arrests for violence and all hospitalizations for mental illness that occurred for individuals in this cohort through the age of 44 years. RESULTS: There was a significant positive relationship between the major mental disorders that led to hospitalization and criminal violence (odds ratios 2.0-8.8 for men and 3.9-23.2 for women). Persons hospitalized for a major mental disorder were responsible for a disproportionate percentage of violence committed by the members of the birth cohort. Men with organic psychoses and both men and women with schizophrenia were significantly more likely to be arrested for criminal violence than were persons who had never been hospitalized, even when controlling for demographic factors, substance abuse, and personality disorders. CONCLUSIONS: Individuals hospitalized for schizophrenia and men hospitalized with organic psychosis have higher rates of arrests for violence than those never hospitalized. This relationship cannot be fully explained by demographic factors or comorbid substance abuse.     

Body mass index and future schizophrenia in Israeli male adolescents

BACKGROUND: Compared with the general population, individuals suffering from schizophrenia are more likely to be overweight, a finding attributed to the effect of antipsychotic medications, poor nutrition, and sedentary lifestyle. As evidence accumulates indicating that some aspects of the illness manifest before the onset of psychosis and establishment of the diagnosis, it has been suggested that increased weight, like other metabolic dysfunctions, might precede active illness. METHOD: Data on height and weight of 203,257 male adolescents assessed by the Israeli Draft Board, and followed for 2-6 years for later hospitalization for schizophrenia using the Israeli National Psychiatric Hospitalization Case Registry, were analyzed. RESULTS: From the entire cohort, 309 (0.15%) were later hospitalized for schizophrenia (ICD-10). After removing adolescents with evidence of illness before or within 1 year of the Draft Board assessment, 204 future schizophrenia patients were available for analysis. Compared with the rest of the cohort, future schizophrenia patients had lower body mass indexes (21.24 +/- 3.3 kg/m2 vs. 21.77 +/- 3.5 kg/m2; F = 4.682, df = 1, p = .03) and weighed slightly but significantly less (64.2 +/- 11.6 kg vs. 66.3 +/- 12.0 kg; F = 6.615, df = 1, p = .01). The mean height of the future patients did not differ significantly from the mean height of the remaining cohort (173.63 +/- 6.7 cm vs. 174.40 +/- 6.9 cm; F = 2.520, df = 1, p = .112). When reanalyzing the data, controlling for physical activity and socioeconomic status, the differences between the groups remained significant. CONCLUSION: Before the onset of illness, future schizophrenia patients are not heavier compared with their peers. This implies that the increased weight of patients with schizophrenia is related to illness effects, including the effects of antipsychotic medication.     

Behavioral and intellectual markers for schizophrenia in apparently healthy male adolescents.

OBJECTIVE: Subtle behavioral and intellectual abnormalities are often present in apparently healthy adolescents who later develop schizophrenia. The authors investigated whether these abnormalities can predict vulnerability for schizophrenia before the first psychotic manifestation. METHOD: The study consisted of linking the Israeli Draft Board Registry with the National Psychiatric Hospitalization Case Registry. The draft board tests measure intelligence, social functioning, organizational ability, interest in physical activity, and individual autonomy. Patients (N = 509) were compared to nonpatients, i.e., adolescents not appearing in the National Psychiatric Registry (N = 9,215), matched to patients by age, gender, and school attended at time of testing. RESULTS: Healthy male adolescents who were later hospitalized for schizophrenia had significantly lower test scores on all measures than adolescents not reported to the National Psychiatric Registry. The strongest predictors for schizophrenia were deficits in social functioning, organizational ability, and intellectual functioning. When patients were compared to matched nonpatients, the prediction model had a 75% sensitivity, a 100% specificity, a positive predictive value of 72%, and an overall rate of correct classification of 87.5%. Applied to the Israeli Draft Board Registry, the model yielded a sensitivity of 74.7%, a validated specificity of 99.7%, and a positive predictive value of 42.7%. CONCLUSIONS: This study demonstrated that simple assessment tools can predict predisposition to schizophrenia in healthy male adolescents. The model's predictive ability does not change as a function of the time elapsed between testing and first hospitalization. This suggests that the model identifies apparently healthy individuals who will manifest the disease later who are not prodromal to psychosis. Easily applied tools allowing early identification of schizophrenia or vulnerability to it may enable early intervention.     

Self-report of family functioning and risk for psychotic disorders in male adolescents with behavioural disturbances

Objective: Previous studies indicate that a poor family environment might affect vulnerability for the later manifestation of psychotic illness. The current study aims to examine family functioning prior to the onset of psychosis. Method: Subjects were 42 948, 17‐year old males with behavioural disturbances who were asked about the functioning of their family by the Israeli Draft Board. Data on later psychiatric hospitalizations were obtained from a National Psychiatric Hospitalization Registry. Results: Poorer self‐reported family functioning was associated with greater risk for later hospitalization for psychosis [adjusted hazard ratio (HR) = 1.16, 95% CI = 1.05–1.27], with a trend in the same direction for schizophrenia (adjusted HR = 1.1, 95% CI = 0.98–1.24). Conclusion: In male adolescents with behavioural disturbances, perceived poorer family functioning is associated with increased risk for non‐affective psychotic disorders and schizophrenia. These data do not enable us to determine if perceived familial dysfunction increases vulnerability for psychosis, if premorbid behavioural abnormalities disrupt family life, or neither.     

Longitudinal association between epilepsy and schizophrenia:A population-based study

A large number of studies have reported an association between epilepsy and major psychiatric conditions. This study investigated the association between epilepsy and later schizophrenia, utilizing a historical-prospective, population-based design. Of the 861,062 17-year-old male adolescents consecutively screened by the Israeli Draft Board and found free of major mental illness, 0.06% suffered from severe, treatment-refractory epilepsy, 0.25% had treated, controlled epilepsy, and 0.16% had a history of seizures which had abated 5 or more years prior to screening. Hospitalization for schizophrenia was ascertained through the Israeli National Psychiatric Hospitalization Case Registry, with an average follow-up of 9.6 ± 1.0 years (range: 1.0–10.0 years). Risk of hospitalization was calculated using Cox regression analyses, compared to socioeconomic-adjusted risk of hospitalization in the general population of male adolescents. Among adolescents whose epilepsy was nonresponsive to medication, the adjusted risk of hospitalization was significantly increased for schizophrenia (HR = 3.89, 95% CI = 1.75–89.67). Male adolescents with successfully treated epilepsy were not at increased risk for schizophrenia.Male adolescents with severe, treatment-refractory epilepsy are at increased risk of later schizophrenia. Future studies attempting to understand the biology of this association might focus on this subset of patients, and these patients should be monitored for the appearance of psychosis.     

Self-reported mental health difficulties and subsequent risk for schizophrenia in females: a 5-year follow-up cohort study

BACKGROUND: Patients with schizophrenia often report a history of premorbid mild to severe psychological distress. We investigated the association between self-reported mental health difficulties and later psychiatric hospitalization for schizophrenia. METHODS: 13,357 females aged 17, mandatory assessed by the Israeli Draft Board were followed up over 5 years for psychiatric hospitalization by means of the Israeli National Psychiatric Hospitalization Case Registry. Seventeen females, judged healthy at Draft Board assessment, were hospitalized for schizophrenia or schizoaffective disorder over the follow-up period. RESULTS: There was a significant monotonic association between increasing self-reported mental health difficulties (psychological distress and increasing need for psychological counseling) and prevalence of schizophrenia [odds ratios over four levels: 1.56; 95% CI:1.04 to 2.34; chi2 (1) = 4.62, p = 0.03], after controlling for low IQ, immigration, SES, and presence of psychiatric disorders at age 17. Increasing severity of self-reported mental health difficulties was related to earlier age of first hospitalization [r = -0.48, p = 0.05]. CONCLUSIONS: Increased undifferentiated self-reported mental health difficulties are associated with increased risk of later hospitalization for schizophrenia prior to age 23 in females. This may reflect the prodromal phase of the illness.     

Inpatient adolescent psychiatry in a teaching hospital in Nigeria

The sociodemographic and clinical characteristics of 84 adolescents admitted to the psychiatric unit of a teaching hospital in Nigeria were studied. Their ages ranged from 12-20 years (mean 17). The pattern of psychiatric disorders in this population reflected the pattern in the adult population. Major psychoses comprising schizophrenia (44%), organic brain syndrome (23%), and affective disorders (16%) predominated. Infections and drug abuse are preventable causes of organic brain syndrome. Male adolescents were as likely to be hospitalized for a major psychiatric disorder as female adolescents. The peak period for psychopathology is late adolescence. The contributions of such factors as rural-urban migration, birth order, family size, polygamy and genetics to the etiology of major mental disorders in this population require further investigations. Understanding the prevalence and pattern of presentation of mental disorders in all age groups is essential for effective mental health planning.     

Adolescents with insomnia and substance abuse: consequences and comorbidities

Adolescents have high rates of sleep disorders and substance abuse, both of which have been associated with deleterious effects on mood, attention, and behavior. This article reviews data on the prevalence of sleep disorders, substance abuse problems, and comorbid psychiatric conditions in the adolescent population. Studies have consistently demonstrated that the prevalence of sleep problems is under-reported in adolescents in both clinical and community samples. The bidirectional correlation between substance use and sleep disturbances is also discussed. Based on the findings presented here, the authors conclude that it is imperative to improve the detection and treatment of sleep problems in children and adolescents. By treating sleep disturbances and targeting poor sleepers with additional counseling and education regarding the risk of substance use, clinicians may be able to prevent or delay the adverse effects of addiction. At the very least, the presence of insomnia should alert clinicians to the need for further evaluation for drug and alcohol abuse.     

Association between functioning in adolescence prior to first admission for schizophrenia and affective disorders and patterns of hospitalizations thereafter

BACKGROUND: Kraepelin and Blueler suggested that subtle manifestations of schizophrenia are present in some persons for many years before formal diagnosis and that the severity of these is associated with outcomes in schizophrenia. Empirical support for this hypothesis comes primarily from small samples using retrospectively collected data. AIMS: We tested this hypothesis, for the first time, using a population-based cohort. METHOD: The Israeli Draft Board Registry, which contains measures of intellectual and behavioral functioning for the unselected population of 17-year-olds, was merged with the National Psychiatric Hospitalization Case Registry that contains data on all psychiatric hospitalizations. The database was used to identify adolescents assessed by the draft board at least 1 year prior to their first hospitalization for schizophrenia (n=996) or affective disorder (n=335). RESULTS: Poorer social functioning and organizational ability prior to first admission were associated with more days per year in the hospital for the male schizophrenia group. There were no significant correlations between days per year in the hospital and any of the behavioral functioning measures for the affective group. Among females the higher the previous level of intellectual functioning the fewer the days per year in the hospital in both the schizophrenia group and affective groups. For males no such correlations were evident. The comparisons between patients who had one as opposed to more than one admission found that in both diagnostic groups female patients with one admission had higher pre-first hospitalization intellectual functioning. CONCLUSIONS: Gender and disease specific premorbid deficits have may have differential prognostic value for outcomes in schizophrenia and affective disorders.     

精神分裂症与糖尿病关系的探讨

目的：了解住院精神分裂症患者中糖尿病的发病情况及其与抗精神病药等因素的关系。方法：回顾性调查符合CCMD－2－R诊断标准的住院精神分裂症患者中的糖尿病发病情况以及抗精神病药的使用情况等相关因素,观察体重、血糖和血脂的变化。糖尿病的诊断按照 WHO关于糖尿病的诊断标准（1980年）作出。将精神分裂症患者中的糖尿病发生率与一般人群中的患病率进行比较,并分析影响糖尿病发生的相关因素。结果：在503例精神分裂症住院患者中,糖尿病的发生率为15．1％,为普通人群（2．5％）的6倍（x^2＝18．10,P＜0．01）。抗精神病药物可引起体重的显著增加(t＝5．45,P＜0．01）。糖尿病的发生与精神分裂症的持续病程、长期住院、患者的年龄以及阳性糖尿病家族史等因素有关。氯氮平对糖尿病的影响与其他抗精神药物无显著差异（x^2＝0．38,P＞0．05）。结论：精神分裂症患者中糖尿病的发生率远高于普通人群,抗精神病药物引起的体重增加可能与此有关,临床上应予以关注。     

Substance abuse in schizophrenia: a review of the literature and a study of correlates in Sweden

The purpose of the current study is twofold: (a) to provide an overall synthesis of recent research on substance abuse in schizophrenia and (b) to present findings in a Swedish patient sample. Studies conducted since 1990 have found a wide range of abuse prevalence rates, with male gender and younger age as primary correlates. Less certainty exists regarding substance abuse as an independent risk factor for schizophrenia and its further impact on illness course. In a sample of 87 patients attending a psychiatric clinic in Malm?, lifetime prevalence of substance abuse was 48.3%, with abuse debut primarily preceding first contact for psychotic symptoms. Significant correlates of abuse were male gender, family history of substance abuse, and increased rates of hospitalization and criminality, with poorer outcome found in previous as well as current abusers. Alcohol abuse, either solely or in combination with other substances, was the main type of substance abuse. Although the specific factors (social, behavioural, genetic) that predispose schizophrenic patients to substance abuse remain unclear, the predominantly male profile of abusers might suggest a link between substance abuse and the poorer clinical outcome frequently observed, especially in male schizophrenic patients.     

A population based elaboration of the role of age of onset on the course of schizophrenia

BACKGROUND: Despite suggestions that an earlier age of onset and being male confer to a poorer course of schizophrenia, evidence regarding when these effects are most salient appears to be ambiguous. AIMS: To examine the relationship of age of first hospitalization and sex with the course of hospitalization in a population based cohort. METHOD: All first admissions for schizophrenia in a national population based cohort in Israel from 1978 to 1992 were followed through 1996 (n=12,071) using data from the National Psychiatric Hospitalization Case Registry of the State of Israel, a complete national registry of psychiatric admissions. Recursive partitioning was conducted to empirically determine cut-off points for age groups showing the greatest difference on the variables of interest. RESULTS: A younger age of first hospital admission was associated with a greater likelihood of having more than one hospital admission, longer first admissions, more hospital admissions and more inpatient days per year. Of patients with age of first admission below 17, 82.5% had more than one admission which decreased for subsequent age groups to 73.54% (18-28), 69.36% (29-31), 62.88% (32-45), and 50.77% (over 45). Men had an earlier first admission than women, and had slightly more cut-off values. Irrespective of sex, the relationship between age at first admission and later hospitalization conformed to a linear trend. CONCLUSIONS: An earlier onset corresponds linearly with the severity of the course of illness and appears to have prognostic value.