A typological model of schizophrenia based on age at onset,sex and familial morbidity

We investigated the age at onset distributions of schizophrenia in men and women and the relationship of age at onset and sex to the familial rates of schizophrenia and manic-depression in data from a Swedish family study of 270 schizophrenic probands. On the logarithmic scale, the age at onset distribution of schizophrenia in both male and female relatives was bimodal, suggesting that broadly defined schizophrenia may be a mixture of 2 (probably related) disorders. The risk of schizophrenia in relatives decreased as a function of the age at onset of the proband, irrespective of the sex of the proband or relative. In contrast, the risk of manic-depression was significantly higher in relatives of female probands with an age at onset in the twenties than in relatives of female probands with earlier or later onset, or in relatives of male probands. This suggests a third disorder related to affective psychosis, with an intermediate age at onset and female preponderance.     

Schizophrenia: age at onset, gender and familial risk

In a family history study of 366 schizophrenic probands and their 1851 first-degree relatives, we found a relationship between age at onset of psychosis in the male probands and the risk for schizophrenia in their relatives. The relatives of male schizophrenic probands whose onset of psychosis occurred when they were younger than 17 years of age had an increased risk of schizophrenia when compared with the relatives of male probands with an age at onset greater than 17. We did not find an association between age at onset of psychosis in the female probands and familial risk. Cox proportional hazards models permitted us to examine the relationship between age at onset of psychosis in the probands and familial risk while controlling for possible confounding effects.     

Age at onset of schizophrenia: gender differences and influence of temporal socioeconomic change

This study was undertaken to examine whether males develop schizophrenia at a younger age than females, and whether temporal socioeconomic change affects the age at onset of schizophrenia. The subjects were 848 ICD-9 schizophrenics who were admitted to Nihon University Hospital, Tokyo, Japan, during the period of 1955-64 (n = 468 (214 males and 254 females), group A) or during the period of 1982-91 (n = 380 (220 males and 160 females). group B). Schizophrenic males showed an earlier age at onset than schizophrenic females. However, the mean age at onset of schizophrenia did not differ significantly between group A and group B. These results indicate that the gender difference in age at onset of schizophrenia has not been influenced by temporal socioeconomic change.     

Does family history of schizophrenia influence age at onset of schizophrenia?

The relation between age at onset of schizophrenia diagnosed using DSM-III criteria and the presence or absence of this illness among first-degree relatives was investigated in 2417 patients. The mean age at onset among those with a family history of schizophrenia was slightly and nonsignificantly earlier than that of schizophrenic patients without a positive family history. The former developed their illness before the age of 25 years more frequently than did the latter.     

Anticipation of age at onset in familial multiple sclerosis

Background and objective: Anticipation of age at onset in the younger generations is a widely known characteristic of many diseases with genetic inheritance. This study was performed to assess whether there is anticipation of age at onset in younger generations of familial multiple sclerosis (MS) in a Spanish population and to compare clinical characteristics of familial and sporadic MS. Methods: We studied a cohort of 1110 patients diagnosed with MS and followed‐up in our MS Unit. Patients were considered as familial MS if they had in their family at least one relative of first or second degree diagnosed with MS. Otherwise, patients were considered to have sporadic MS. We compared the age at onset between relatives from different generations, and we also compared the age at onset of familial and sporadic MS. Results: A lower age at onset in the younger generations was found (median 22 years vs. 30 years, P < 0.001) and a significant lower age at onset of the disease in familial MS comparing to sporadic MS (median 25 years vs. 29 years, P = 0.042). Conclusions: There is an anticipation of the age at onset of MS in the younger generations of patients with familial MS. There is also a lower age at onset in familial versus sporadic MS.     

Gender and schizophrenia: age at onset and sociodemographic attributes.

A consecutive series of 214 patients (125 males, 89 females) who met the Research Diagnostic Criteria for schizophrenia were studied to determine gender differences in age at onset of the illness and sociodemographic attributes. The immediate family's first awareness of psychotic symptoms or signs and age at first presentation in hospital were used as indices of onset; male patients had a significantly earlier age of onset than females. By the time they were 30 years of age, 83% of male patients had already become ill and only 66% of females had done so. Significantly more females than males were married at the time of first contact with hospital. Married males did not differ from married females in age at onset of illness, suggesting that patients who marry may have late onset.     

Influence of Sex on Age at Onset of Schizophrenia

Abstract: The age at onset of schizophrenia was investigated in 2,417 inpatients (1,433 males and 984 females) meeting the DSM-III criteria for schizophrenia. About 80% of the patients became schizophrenic before the age of 30. The mean age at onset of the male patients was slightly earlier than that of the female patients. There was a higher cumulative percentage of the male patients who became affected at each age quinquennium. More men than women became schizophrenic before the age of 30.     

Familial-genetic and reproductive epidemiology of schizophrenia in rural Ireland: age at onset,familial morbid risk and parental fertility

Waddington JL and Youssef HA. Familial-genetic and reproductive epidemiology of schizophrenia in rural Ireland: age at onset, familial morbid risk and parental fertility Acta Psychiatr Scand 1996: 93: 62–68. © Munksgaard 1996. Among all ascertainable cases of DSM IIIR schizophrenia within an unusually homogeneous region of rural Ireland, family history information was sought from multiple sources. Morbid risk for schizophrenia among probands' first degree relatives was 6.1% and did not differ between male (6.5%) and female (5.5%) probands; risk among probands' siblings (8.3%) exceeded that among their parents (1.4%), with only 2% of male and 31% of female probands being themselves married. Both age at onset <25 and having >7 siblings were associated with elevated morbid risk, particularly among relatives of male probands (11.9% vs. 2.2% and 11.8% vs. 3.7%, respectively). Increased fertility particularly among parents of male patients with high familial-genetic loading may contribute to perpetuation of the disorder in the face of those patients' own extremely low fecundity.     

Sex difference in age at onset of schizophrenia: discrepant findings from India

Consecutive male (n=100) and female (n= 100) DSM-IV schizophrenics newly registered for treatment in a large psychiatric hospital were examined with regard to age at onset of the first psychotic symptom. Age at onset of the first psychotic symptom did not differ between the sexes regardless of whether schizophrenia was diagnosed by DSM-IV or by several alternative systems. Age at onset defined by other criteria, namely age at first contact with a physician, and age at first admission for psychiatric care, also did not show any differences between the sexes. Survival analysis of subjects having a documented date of birth revealed a female preponderance at younger ages. A higher positive symptom score predicted older age at onset of the first psychotic symptom in the total sample. These findings call into question the universality of the traditional view of a younger age at onset of schizophrenia among males. Tentative neurodevelopmental and cultural explanations are presented to explain why there is no sex difference in age at onset of schizophrenia in India.     

An analysis of the clinical features of familial schizophrenia

Clinical features of familial schizophrenia were examined in 169 siblings from 80 families. Factor analysis of symptoms produced a negative symptom factor (affective flattening and negative thought disorder), a disorganization factor (inappropriate affect and positive thought disorder) and a reality distortion factor (delusions and hallucinations). The negative symptom factor correlated positively with duration of illness and poor outcome. The disorganization factor correlated positively with poor outcome and early age at onset. The only clear correlation between these factors and affective symptoms was a negative one between the negative symptom factor and mania. There were no significant gender differences in age at onset, factor scores or outcome. The implication of these findings in relation to recent research in the areas of psychopathology and epidemiology are discussed.     

Comparison of adult manifestations of schizophrenia with onset before and after 15 years of age

We examined 19 adult cases of early-onset schizophrenia (onset before age 15) and 19 controls (schizophrenia with onset between age 15 and 35). Being matched by sex, length of hospitalization and living environment while the present age between groups showed no difference, patients were compared on psychopathological symptom measures and intelligence quotient (IQ). Results showed that early-onset cases scored significantly higher on Scales for the Assessment of Negative Symptoms and had lower performance IQ. No group difference in positive symptoms measure from Brief Psychiatric Rating Scale and full IQ was noted. It suggested that when early-onset patients grew up, phenomenologically, they resembled the schizophrenia of usual early-adult onset in the positive symptom dimension, but with more negative symptoms, which may be fundamental in this group of patients.     

Analysis of familial and sporadic restless legs syndrome in age of onset,gender, and severity features

Abstract Restless Legs Syndrome is characterized by the irresistible, often indescribable unpleasant urge to move the limbs while resting. It has an estimated prevalence of ~29.3 % in US private practice. Restless Legs Syndrome often has a familial component; whether the familial and non-familial forms differ in terms of clinical features has previously been investigated, with the only significant factor emerging as younger age at onset in familial cases. Our study further explores a possible underlying difference between familial and sporadic forms of RLS by comparing familial RLS with sporadic RLS in terms of demographic and clinical features including subject gender, age of onset, and severity measures based an the IRLSSG severity scale. Both gender and family history are significant predictors of onset age in an overall model and also significant when analyzed independently. Participants who reported more severe RLS symptoms were significantly younger in age and progressed more rapidly. Two variables from the IRLSSG severity scale were significantly associated with age of onset when tested independently: discomfort and the urge to move the limb for relief. Our analysis supports the prevailing hypothesis that RLS is divided into earlier onset disease with a clear genetic component and later onset disease wich unclear etiology, and that one or more endophenotypes might exist within the disorder which could further characterize these subjects for future genetic studies.     

Age at onset in a cohort of schizophrenics in Nigeria.

Over a period of 3 years, 340 patients (199 men and 141 women) who met DSM-III-R criteria for schizophrenia and who knew their exact date of birth were interviewed to determine the age at onset of illness. The immediate family's first awareness of psychotic symptoms was used as the index of onset. Men had a significantly earlier mean age at onset (24 +/- 6) than the women (27 +/- 8). By the time they were 30 years of age, 83% of the men and 66% of the women had become ill. The findings are remarkably similar to those of an earlier report in the same cultural setting, and add to the evidence of sex differences in age at onset of schizophrenia.     

The impact of gender and age at onset on the familial aggregation of schizophrenia

Summary Some recent family studies have shown that the familial risk for schizophrenia is higher in female than in male schizophrenics. It is debated whether the risks for the other disorders, such as schizotypal personality disorder or affective disorders in families of schizophrenics are similarly influenced by the proband's gender. Also, the reason for the effect of proband's gender on the recurrence risk for schizophrenia has not been clarified. This family study (159 probands, 589 first degree relatives) confirms that schizophrenia, but also schizophrenia spectrum disorders were more frequent in families of female compared with male schizophrenics. Neither age at onset in probands nor the interaction between gender and age at onset in probands had a relevant impact on the risk figures in relatives. Affective disorders occurred in families independently of the probands' gender. Aetiological heterogeneity or ascertainment bias may account for the modifying effect of proband's gender in schizophrenia.     

Gender differences in age at onset of Schizophrenia

Summary We present the results of a review of the literature concerning gender differences in age at the onset of schizophrenia. In view of the very consistent finding that the first admission to hospital for schizophrenia occurs on average earlier in men than in women we examined the question whether this is due to the fact that the psychosis manifests itself earlier in men or that the period between first manifestation and admission to hospital is shorter than in women. By means of a metaanalytic approach we then looked for evidence for the existence of local or temporal variations in the degree of gender difference. Lastly, we dealt with the question whether gender differences in age of onset can be observed in other functional psychoses.     

精神分裂症患者发病年龄与临床特征的相关性研究

目的 探讨精神分裂症发病年龄与临床特征的关系。方法 对符合DSM-IV精神分裂症诊断标准的294例住院患者进行BPRS评估和BEAM检查，并收集其人口学资料和病史资料。结果 BPRS总分和迟滞因子分与发病年龄呈负相关，而BPRS总分、迟滞因子分和敌对猜疑因子分与未治疗期的长短呈正相关。发病年龄在性别和遗传因素中的差异无显著性，而在发病诱因、BEAM检查结果和诊断类型间的差别有统计学意义。结论 精神分裂症的临床特征与发病年龄明显相关，发病年龄越小病情越严重，阴性症状也越突出，提示在制定治疗康复方案方面，应有所区别。