Seasonal spring peaks of suicide in victims with and without prior history of hospitalization for mood disorders.

BACKGROUND: Seasonal spring peaks of suicide are highly replicated, but their origin is poorly understood. As the peak of suicide in spring could be a consequence of decompensation of mood disorders in spring, we hypothesized that prior history of mood disorders is predictively associated with suicide in spring. METHODS: We analyzed the monthly rates of suicide based upon all 37,987 suicide cases in the Danish Cause of Death Registry from 1970 to 2001. History of mood disorder was obtained from the Danish Psychiatric Central Register and socioeconomical data from the Integrated Database for Labour Market Research. The monthly rate ratio of suicide relative to December was estimated using a Poisson regression. Seasonality of suicide between individuals with versus without hospitalization for mood disorders was compared using conditional logistic regression analyses with adjustment for income, marital status, place of residence, and method of suicide. RESULTS: A statistically significant spring peak in suicide was observed in both groups. A history of mood disorders was associated with an increased risk of suicide in spring (for males: RR=1.18, 95% CI 1.07-1.31; for females: RR=1.20, 95% CI 1.10-1.32). LIMITATIONS: History of axis II disorders was not analyzed. Danish socioeconomical realities have only limited generalizability. CONCLUSIONS: The results support the need to further investigate if exacerbation of mood disorders in spring triggers seasonal peaks of suicide. Identifying triggers for seasonal spring peaks in suicide may lead to uncovering novel risk factors and therapeutic targets for suicide prevention.

Disturbed sleep: linking allergic rhinitis, mood and suicidal behavior.

Allergic inflammation is associated with mood disorders, exacerbation of depression, and suicidal behavior. Mediators of inflammation modulate sleep , with Th1 cytokines promoting NREM sleep and increasing sleepiness and Th2 cytokines (produced during allergic inflammation) impairing sleep. As sleep impairment is a rapidly modifiable suicide risk factor strongly associated with mood disorders, we review the literature leading to the hypothesis that allergic rhinitis leads to mood and anxiety disorders and an increased risk of suicide via sleep impairment. Specifically, allergic rhinitis can impair sleep through mechanical (obstructive) and molecular (cytokine production) processes. The high prevalence of mood and anxiety disorders and allergy, the nonabating suicide incidence, the currently available treatment modalities to treat sleep impairment and the need for novel therapeutic targets for mood and anxiety disorders, justify multilevel efforts to explore disturbance of sleep as a pathophysiological link.

Changes in Severity of Allergy and Anxiety Symptoms Are Positively Correlated in Patients with Recurrent Mood Disorders Who Are Exposed to Seasonal Peaks of Aeroallergens.

Considering clinical and animal evidence suggesting a relationship between allergy and anxiety, we hypothesized that, from low to high aeroallergen exposure, changes in anxiety symptom scores in patients with primary mood disorders will correlate with changes in allergy symptom scores. We also anticipated that sensitization to tree pollen, as determined by allergen specific IgE antibodies, will predict a greater worsening of anxiety during exposure to tree pollen. 51 patients with unipolar or bipolar disorder (age: 19-63 years, 65% female) were recruited. Tree- pollen IgE positive subjects (12) were included as the experimental group and patients negative to a multi-allergen serological test (39) were included in the control group. Self reports of anxiety and allergy symptoms were obtained once during the peak airborne pollen counts and once during the period of low airborne pollen counts, as reported by two local pollen counting stations. Using linear regression models, we confirmed a significant positive association between allergy scores and anxiety scores (p<0.04); however, the IgE specific tree pollen positivity was not significantly associated with changes in anxiety scores. Because changes in anxiety scores relate to changes in depression scores, the relationship between allergy and anxiety involves states rather than only traits, and as such, our results lead to future efforts to uncover potential anxiety triggering, exacerbating or perpetuating role of allergens in vulnerable individuals.

Seasonal variations in mood and behavior in Romanian postgraduate students.

To our knowledge, this paper is the first to estimate seasonality of mood in a predominantly Caucasian sample, living in areas with hot summers and a relative unavailability of air conditioning. As a summer pattern of seasonal depression was previously associated with a vulnerability to heat exposure, we hypothesized that those with access to air conditioners would have a lower rate of summer seasonal affective disorder (SAD) compared to those without air conditioning. A convenience sample of 476 Romanian postgraduate students completed the Seasonal Pattern Assessment Questionnaire (SPAQ), which was used to calculate a global seasonality score (GSS) and to estimate the rates of winter- and summer-type SAD. The ratio of summer- vs. winter-type SAD was compared using multinomial probability distribution tests. We also compared the ratio of summer SAD in individuals with vs. without air conditioners. Winter SAD and winter subsyndromal SAD (S-SAD) were significantly more prevalent than summer SAD and summer S-SAD. Those with access to air conditioners had a higher, rather than a lower, rate of summer SAD. Our results are consistent with prior studies that reported a lower prevalence of summer than winter SAD in Caucasian populations. Finding an increased rate of summer SAD in the minority of those with access to air conditioners was surprising and deserves replication.

A prospective longitudinal study of seasonality in African students living in the greater Washington, D.C. metropolitan area.

We conducted a prospective, longitudinal study of seasonality in a vulnerable population, i.e., African students who migrated to a temperate climate. Consistent with previous cross-sectional studies, we hypothesized lower mood and energy, and higher appetite and weight, in fall/winter than in spring/summer. Four cohorts of African students attending a year-long nursing school program without vacation in Washington, D.C., were assessed monthly for 1 year. Forty-three subjects (mean age = 33.46 +/- 6.25), consisting of predominantly females (76.7%), completed the study. The cohorts began their academic program in different seasons (one each in winter, spring, summer, and fall), inherently minimizing confounding influences on seasonality, such as academic and immigration stress, as well as allowing adjustment for an order effect. At each assessment, students completed three 100-mm visual analog scales for mood, energy, and appetite, and were weighed on a digital scale. For each standardized dependent variable, a repeated measure ANOVA was used and, if a significant effect of month was identified, averages for spring/summer and fall/winter were compared using paired t-tests. In addition, a mixed model for repeated measures was applied to raw (nonstandardized) data. Body weight was significantly higher in fall/winter than in spring/summer (p < 0.01). No seasonal differences in mood, energy, or appetite were found. Benefiting from certain unique features of our cohorts allowing adjustment for order effects, this is the first study to identify a seasonal variation in body weight with a peak in winter using longitudinal monthly measurements.

Mood sensitivity to seasonal changes in African college students living in the greater Washington D.C. metropolitan area.

The purpose of this study was to estimate the degree of seasonality and prevalence of winter- and summer-type seasonal affective disorder (SAD) in African immigrant college students in comparison with African American peers. A convenience sample of 246 African immigrants and 599 African Americans studying in Washington, D.C. completed the Seasonal Pattern Assessment Questionnaire (SPAQ), which was used to calculate a global seasonality score (GSS) and to estimate the prevalence of winter- and summer-type SAD. Degree of seasonality was related to a complex interaction between having general awareness of SAD, ethnicity, and gender. A greater percentage of African students reported experiencing a problem with seasonal changes relative to African American students, and had summer SAD, but the groups did not differ on GSS and winter SAD. African students reported more difficulties with seasonal changes than their African American peers, which could represent a manifestation of incomplete acclimatization to a higher latitude and temperate climate. As Africans also had a greater rate of summer SAD, this argues against acclimatization to heat.

Mood-worsening with high-pollen-counts and seasonality: a preliminary report.

BACKGROUND: Because aeroallergens produce inflammation in the respiratory airways, and inflammation triggers depression in vulnerable individuals, we hypothesized that mood sensitivity to pollen, the most seasonal aeroallergen, will be associated with a greater seasonality of mood. Since pollen is absent during winter, we specifically predicted that mood sensitivity to tree pollen will predict non-winter SAD but not winter SAD. METHODS: A convenience sample of African and African American college students who lived in the Washington DC metropolitan area for at least the past 3 years completed the Seasonal Pattern Assessment Questionnaire (SPAQ), from which the Global Seasonality Score (GSS) was calculated, a diagnosis of cumulative SAD (syndromal or subsyndromal SAD) was derived, a seasonal pattern (winter vs non-winter) identified, and self-reported mood changes during high pollen counts obtained. A Mann-Whitney test was used to compare GSS between participants with vs without mood worsening during high pollen counts. The capability of mood worsening with high pollen counts, gender, ethnicity, and age to predict non-winter SAD was analyzed with logistic regressions. RESULTS: GSS was greater (z=5.232, p<0.001) in those who reported mood worsening with high pollen counts. Mood sensitivity to pollen predicted non-winter SAD (p=0.017), but not winter SAD. LIMITATIONS: The SPAQ is not a definitive tool to assess seasonality, and self-reported mood worsening with high pollen counts relies on recollection. No direct measures of depression scores or pollen counts were collected. The non-winter SAD concept has not been previously established. CONCLUSIONS: Our study, which should be considered preliminary in light of its limitations, suggests that self-reported mood-worsening with high pollen count is associated with a greater seasonality of mood, and predicts SAD of non-winter type.

Changes in allergy symptoms and depression scores are positively correlated in patients with recurrent mood disorders exposed to seasonal peaks in aeroallergens.

Although growing evidence supports an association between allergy, allergens and depression, it remains unknown if this relationship is between "states" (possible triggers) or "traits" (possible vulnerabilities). We hypothesized that patients with recurrent mood disorders who are sensitized to tree pollen (as determined by allergen specific IgE antibodies), in comparison to those who are not sensitized, would report larger negative changes in mood during exposure to tree pollen in spring. We also hypothesized that differences between high and low tree pollen periods in self reported allergy symptoms would correlate positively with differences in self reported depression scores. We present 1-year preliminary data on the first 51 patients with unipolar or bipolar disorder (age: 19-63 years, 65% female, twelve patients were tree-pollen IgE positive). Ratings of mood and allergic disease status were performed once during the peak airborne pollen counts and once during the period of low airborne pollen counts, as reported by two local pollen counting stations. Linear regression models were developed to examine associations of changes in depression scores (dependent variable) with tree pollen sensitization, changes in the allergy symptom severity score, adjusted for gender and order of testing. We did not confirm the hypothesized relationship between a specific tree pollen sensitization and changes in mood during tree pollen exposure. We did confirm the hypothesized positive relationship between the changes in allergy symptoms and changes in subjects' depression scores (adjusted p<0.05). This result is consistent with previous epidemiological evidence connecting allergy with depression, as well as our recent reports of increased expression of cytokines in the prefrontal cortex in victims of suicide and in experimental animals sensitized and exposed to tree pollen. A relationship between changes in allergy symptom scores and changes in depression scores supports a state-level rather than only trait-level relationship, and thus lends optimism to future causality-testing interventional studies, which might then lead to novel preventative environmental interventions in mood disorders.

Sports chronobiology consultation: from the lab to the arena.

This final article, coauthored by a chronobiology consultant, a sports psychologist who applied a chronobiology-based program to an Olympic national team, a clinical neurologist, a performance data analyst, a training-conditioning coach from a major league baseball team who applied chronobiology principles to major league pitchers, and a substance abuse expert, discusses practical aspects of a sports chronobiology consultation, including the goals and current arsenal of available interventions. Short vignettes of actual cases are presented for edification, and references are made to appropriate reviews found elsewhere in this issue.