Season of birth: comparison of patients with schizophrenia, affective disorders and alcoholism

Impact of Season of Birth on Psychiatric Disorder Susceptibility and Drug Abuse Incidence in a Population from the Köppen Tropical Savanna Region of Brazil

BACKGROUND

Despite much evidence that season of birth (SOB) my influence the vulnerability to psychiatric disorders, divergence has been reported, in particular between populations born in the northern and southern hemispheres. We analyzed the potential modified risk by SOB to psychiatric disorder or drug addiction comorbidity in a population born in the Triângulo Mineiro region, a southern hemisphere Köppen tropical savanna region in Brazil.

METHOD

We accessed the records of 98,457 of patients and healthy controls of the National Datacenter of Medical Promptuary to evaluate the influence of SOB as a modifying factor on the occurrence of mental disorders and drug abuse conditions among individuals born from the year 2000 to 2016.

RESULTS

The data revealed significant modification of the relative incidence of major depressive disorder (MDD) (F11, 72 = 2.898; p = 0.003; eta-squared, ES = 0.313; ⍺ = 0.97), anxiety-related disorder (ARD) (F11, 81 =2.389; p = 0.013; ES = 0.241; ⍺ = 0.932), and schizophrenia (SZ) (F11, 83 = 2.764; p = 0.005; ES = 0.303; α = 0.963), while there was no increase in the number of healthy controls born in any month of the year (F11, 71 = 1.469; p = 0.163). Post hoc analyses indicated a significant higher vulnerability to MDD or ARD if the patient was born in August, or October to December, respectively. A relative increase in the incidence of SZ was also observed in patients born from August to October, compared to patients born from November to January.

CONCLUSIONS

SOB may influence the risk for psychiatric disorders in the TMR population. Regional particularities associated with the climatic regime may account for the apparent divergence between studies.

Seasonal distribution of births in patients with Alzheimer’s disease and elderly depressive patients

Winter births have been associated with a higher risk of Alzheimer’s disease (AD) and other psychiatric disorders. In the present investigation, this putative association was examined in a sample of gerontopsychiatric patients. An analysis of the quarterly birth rates of 83 patients with AD, 78 elderly depressive patients with an early onset and 74 patients with a late onset of the depressive disorder, 48 patients with both AD and depression (co-morbid patients) and 107 healthy control subjects, revealed no particular seasonal distribution for any of the diagnostic groups. In AD and co-morbid patients, controlling for the ApoE genotype did not change this finding. Logistic regression analysis revealed the expected findings that increasing age and the presence of the ApoE4 allele were associated with a higher risk of dementia. Younger age and female gender were identified as risk factors for a depressive disorder. A winter birth (birth in the first three months of the year) was not associated with any of the diagnostic subgroups.

We concluded that in our sample a seasonal distribution of births was not found to increase the risk for AD or geriatric depression.

Month of birth and cause-specific mortality between 50 and 80 years: a population-based longitudinal cohort study in Sweden

Month of birth-a proxy for a variety of prenatal and early postnatal exposures including nutritional status, ambient temperature and infections-has been linked to mortality risk in adult life. We assessed the relation between month of birth and cause-specific mortality risk from cardiovascular diseases, infections, tumors and external causes-in ages of more than 50-80 years. In this nation-wide Swedish study, 4,240,338 subjects were followed from 1991 to 2010, using data from population-based health and administrative registries. The relation between month of birth and cause-specific mortality risk was assessed by fitting Cox proportional hazard regression models with attained age as the underlying time scale. In models adjusted for sex and education, month of birth was associated with cardiovascular and infectious mortality, but not with deaths from tumors or external causes. Compared with subjects born in November, a higher cardiovascular mortality was seen in subjects born from January through August, peaking in March/April [hazard ratio (HR) 1.066 compared to November, 95 % CI 1.045-1.086]. The mortality from infections was lowest for the birth months November and December and a distinct peak was observed for September-born (HR 1.108 compared to November, 95 % CI 1.046-1.175). Month of birth is associated with mortality from cardiovascular diseases and infections in ages of more than 50-80 years in Sweden. The mechanisms behind these associations remain to be elucidated.

Season of birth, mixed-handedness, and psychometric schizotypy: preliminary results from a prospective study

Season of birth and hand preference were examined in a sample of 42 (7 males, 35 females) individuals who were identified as schizotypic based on their scores on selected scales of the Chapman Psychosis Proneness Scales (CPPS) and a matched comparison sample of 42 individuals with non-deviant CPPS scores. Presence or absence of schizotypy was analyzed using chi square tests of independence with the presence or absence of each risk factor serving as the independent variable. Further analyses incorporated independent means t tests to examine mean scores on the CPPS with the presence or absence of each risk factor again serving as the independent variable. Results supported the hypothesis that winter/early-spring birth would be associated with psychometric schizotypy, although the results for mixed-handedness fell just short of statistical significance. However, mixed hand preference was associated with higher scores on MagId and PerAb scales of the CPPS, but not the RSA scale, which suggests that mixed laterality is associated with the more cognitive-perceptual aspects of schizotypy. Results are discussed in relation to previous literature and their relevance to the prediction of schizophrenia-related psychosis.

Prenatal exposure to the 1944-45 Dutch 'hunger winter' and addiction later in life

AIMS

Prenatal exposure to severe famine has been associated with an increased risk of schizophrenia and affective disorders. We studied the relationship between prenatal exposure to famine during the Dutch hunger winter of 1944-45 and addiction later in life.

DESIGN

A case-control study.

SETTING

The Rotterdam city area during the Dutch hunger winter lasting from mid-October 1944 to mid-May 1945. From February 1945 to mid-May 1945 the hunger winter was characterized by a famine peak.

PARTICIPANTS

Patients are native Dutch addicted patients from the Rotterdam Addiction Treatment Program and controls are native Dutch inhabitants of Rotterdam, born between 1944 and 1947.

MEASUREMENT

Exposure to the whole hunger winter (< 1400 kcal/day) and the peak of the hunger winter (< 1000 kcal/day) was determined for each trimester of gestation. For each trimester the exposed/unexposed ratios were compared between patients and controls and quantified as odds ratios (OR).

FINDINGS

The odds of first-trimester gestational exposure to famine during the total hunger winter was significantly higher among patients receiving treatment for an addictive disorder [OR = 1.34, 95% confidence interval (CI) 1.10-1.64]. Stratification by sex shows that the odds of exposure during the first trimester was significantly higher only among men (OR = 1.34, 95% CI 1.05-1.72), but not among women (OR = 1.26, 95% CI 0.88-1.81). The odds of exposure to the peak of the hunger winter during the first trimester of gestation were also significantly higher among addiction treatment patients (OR = 1.61, 95% CI 1.22-2.12). We did not find any significant differences for the second and third trimesters of gestation.

CONCLUSION

First-trimester prenatal exposure to famine appears to be associated with addiction later in life. The study confirms the adverse influence of severe malnutrition on brain development and maturation, confirms the influence of perinatal insults on mental health in later life and gives rise to great concern about the possible future consequences for the hunger regions in our world.

Season of birth effect on personality in a general population

Seasonality of births in schizophrenia and other mental disorders has been consistently observed. This may be through effects of unknown environmental factors that seasonally fluctuate on the brain development. The effects may affect cognitive function of the brain and behavioral characteristics that might be correlated with the development of personality not only in patients with mental disorders but also in healthy subjects. We, therefore, investigated the effects of season of birth on personality traits in healthy Japanese adults (n = 397). Personality traits were evaluated using the NEO Personality Inventory-Revised (NEO PI-R). A trend for lower Agreeableness in subjects born during winter (December to February) than other subjects was observed (P = 0.036, after correction for the multiple testing, multiple regression analysis adjusting for age and sex). Other major factors of the NEO PI-R, including Neuroticism, Extraversion, Openness and Conscientiousness, were not affected by season of birth. Further studies may be recommended to confirm the results, considering the relatively limited sample size. Evaluation of cognitive functions and behaviors using other measures including event-related potentials and functional MRI may also help the interpretation of the present result.

Season of birth in females with anorexia nervosa in Northeast Scotland

OBJECTIVE

To determine whether patients with anorexia nervosa exhibit an abnormal pattern in their season of birth.

METHOD

Case records of female patients presenting to secondary services in Northeast Scotland from 1965 to 1997 who received a clinical diagnosis of anorexia nervosa were examined. The months of birth of the 446 anorexic patients with a confirmed diagnosis were compared with 5,766 female control subjects born locally in 1951, 1961, 1971, and 1981.

RESULTS

Patients with anorexia nervosa had an excess of births in the first 6 months of the year (p =.013). The greatest excess was from March to June.

DISCUSSION

This provides further evidence that birth dates of anorexics peak in the late spring and early summer. There are parallels with the epidemiology of schizophrenia. The evidence suggests that a seasonally fluctuating factor, most plausibly an intrauterine effect of common infectious agents during the winter months, is of etiological significance.

Prenatal illness and subtypes of schizophrenia: the winter pregnancy phenomenon

Seasonality of birth patterns is examined among a sample of 801 patients with schizophrenia separated into Type I and Type II schizophrenia. Findings indicate that both groups of patients were in utero during the winter but during different trimesters. Patients with Type I schizophrenia were more likely to be in utero during the third trimester. Patients with Type II schizophrenia were more likely to have been in the womb during the first trimester. Implications for fetal brain development are discussed.

Alcoholic typology and season of birth

OBJECTIVE

This study analyzed the half years of birth of a large (n = 113,276) population of alcoholic patients in the U.S. Army Alcohol and Drug Abuse Prevention and Control Program from 1986 through 1990.

METHOD

Subjects were enrolled for treatment of alcoholism or alcohol-related problems, and were analyzed for half year of birth. Groupings by age and gender, consistent with current theories of alcoholic typology, were compared, by means of chi-square tests, and by comparisons of two rates or proportions.

RESULTS

The 17-21 year old and the 22-39 year old age groups differed by 5.1% in regard to half year of birth (chi-square = 260.317, p < 0.001, 95% CI:4.481 to 5.725, odds ratio: 1.23). Both groups differed significantly from the normal circannual birth pattern, but in opposite directions.

CONCLUSIONS

The findings support the differentiation of types of alcoholics by age, which is a characteristic of Cloninger's classification, suggesting a biological, pre-natal factor.

Seasonality of births in schizophrenia and bipolar disorder: a review of the literature

More than 250 studies, covering 29 Northern and five Southern Hemisphere countries, have been published on the birth seasonality of individuals who develop schizophrenia and/or bipolar disorder. Despite methodological problems, the studies are remarkably consistent in showing a 5-8% winter-spring excess of births for both schizophrenia and mania/bipolar disorder. This seasonal birth excess is also found in schizoaffective disorder (December-March), major depression (March-May), and autism (March) but not in other psychiatric conditions with the possible exceptions of eating disorders and antisocial personality disorder. The seasonal birth pattern also may shift over time. Attempts to correlate the seasonal birth excess with specific features of schizophrenia suggest that winter-spring births are probably related to urban births and to a negative family history. Possible correlations include lesser severity of illness and neurophysiological measures. There appears to be no correlation with gender, social class, race, measurable pregnancy and birth complications, clinical subtypes, or neurological, neuropsychological, or neuroimaging measures. Virtually no correlation studies have been done for bipolar disorder. Regarding the cause of the birth seasonality, statistical artifact and parental procreational habits are unlikely explanations. Seasonal effects of genes, subtle pregnancy and birth complications, light and internal chemistry, toxins, nutrition, temperature/weather, and infectious agents or a combination of these are all viable possibilities.

Season of birth of schizophrenics in a recent Japanese sample

An excess of schizophrenic births in winter or early spring is a well replicated finding in studies on Western populations. However, there are few studies on Asian populations, and their results are not consistent. We examined the seasonality of schizophrenic births in Japanese subjects (n = 1024) born between 1955 and 1960. Our results showed a significant inverse relationship between temperature and number of schizophrenic births, which is in line with the findings in Western populations. In our data, observed reduction of schizophrenic births in summer was more marked than excess births in winter. We suggest the possibility that birth in summer may have some advantage in brain growth early in life, which results in reducing the risk of developing schizophrenia.

Birth seasonality in bipolar disorder, schizophrenia, schizoaffective disorder and stillbirths

BACKGROUND

More than 40 studies have been done on seasonal birth patterns for schizophrenia, but only two small studies have been done for DSM-III-R bipolar disorder and none for schizoaffective disorder. Two studies have also reported a significant relationship between schizophrenia births and stillbirths.

METHODS

In the largest study to date, birth data from four states was obtained on 126,987 state psychiatric hospitals inpatients divided into 'process' schizophrenia (disorganized, catatonic, undifferentiated), paranoid schizophrenia, schizoaffective disorder, bipolar disorder and major depression. Time series analysis compared these births to all general births and to stillbirths.

RESULTS

'Process' schizophrenia, paranoid schizophrenia, schizoaffective disorder and bipolar disorder all had statistically significant seasonal excess births from December through March (p = 0.0000). The largest excess was 5.8% for bipolar disorder. Major depression had significant excess births from March through May. Time series analysis showed statistically significant coherences between major depression and bipolar disorder (0.995) and between schizoaffective disorder and both 'process' schizophrenia (0.977) and bipolar disorder (0.977). Unexpectedly, a significant coherence was also found between paranoid schizophrenia and bipolar disorder (0.972). Excess stillbirths were found for each month from January through June and a significant coherence was found between stillbirths and paranoid schizophrenia (0.998).

CONCLUSIONS

This study demonstrates that DSM-III-R bipolar disorder and schizoaffective disorder both have an excess of winter births, similar to that found in schizophrenia. Time series analysis, however, suggests that the causes may not be identical. Major depression, by contrast, has an excess of spring births.

Biological rhythms in the human life cycle and their relationship to functional changes in the suprachiasmatic nucleus

Biological rhythms play a prominent role in the human life cycle. The endogenous rhythms are entrained by the environment and have an astronomical counterpart which is obvious for daily, monthly, and yearly rhythms, and may possibly also be present in weekly rhythms. Circadian rhythms are present in, e.g. testosterone levels, spontaneous birth, strokes, and death from cardiovascular causes. Circaseptan rhythms are present in, e.g. spontaneous birth, 17-ketosteroid levels, myocardial infarctions, and strokes. The relationship of these rhythms with the suprachiasmatic nucleus (SCN) has not yet been established. Circatrigintan rhythms, such as the menstrual cycle, have so far not been associated with the SCN. Circannual rhythms are present in, e.g. mood, suicides, reproduction, birth weight, sleep and season of birth of psychiatric patients. The human SCN shows strong circadian and circannual fluctuations in the number of neurons expressing vasopressin. The vasopressin and VIP cell population of the SCN develop late, i.e. for a major part postnatally. After the age of 50 the amplitudes of circadian and circannual fluctuations of the vasopressin cell numbers are reduced whereas the number of vasopressin expressing neurons decreases after the age of 80 and do so even more and earlier in Alzheimer's disease. Sex differences are present in the shape of the vasopressin subnucleus of the SCN and in the vasoactive intestinal polypeptide (VIP) cell number. The sex differences in the SCN, the doubling of the number of vasopressin neurons in the SCN of homosexual men, and a variety of animal experimental observations indicate that the SCN is involved in sexual behavior and reproduction. The exact role of the SCN in these processes is subject to current research.