Season of birth, clinical manifestations and Dexamethasone Suppression Test in unipolar major depression

An epidemiological study of season of birth, mental health, and neuroimaging in the UK Biobank

Environmental exposures during the perinatal period are known to have a long-term effect on adult physical and mental health. One such influential environmental exposure is the time of year of birth which affects the amount of daylight, nutrients, and viral load that an individual is exposed to within this key developmental period. Here, we investigate associations between season of birth (seasonality), four mental health traits (n = 137,588) and multi-modal neuroimaging measures (n = 33,212) within the UK Biobank. Summer births were associated with probable recurrent Major Depressive Disorder (β = 0.026, pcorr = 0.028) and greater mean cortical thickness in temporal and occipital lobes (β = 0.013 to 0.014, pcorr<0.05). Winter births were associated with greater white matter integrity globally, in the association fibers, thalamic radiations, and six individual tracts (β = -0.013 to -0.022, pcorr<0.05). Results of sensitivity analyses adjusting for birth weight were similar, with an additional association between winter birth and white matter microstructure in the forceps minor and between summer births, greater cingulate thickness and amygdala volume. Further analyses revealed associations between probable depressive phenotypes and a range of neuroimaging measures but a paucity of interactions with seasonality. Our results suggest that seasonality of birth may affect later-life brain structure and play a role in lifetime recurrent Major Depressive Disorder. Due to the small effect sizes observed, and the lack of associations with other mental health traits, further research is required to validate birth season effects in the context of different latitudes, and by co-examining genetic and epigenetic measures to reveal informative biological pathways.

Perinatal photoperiod associations with bipolar disorder and depression: A systematic literature review and cross-sectional analysis of the UK Biobank database

Season-of-birth associations with psychiatric disorders point to environmental (co-)aetiological factors such as natural photoperiod that, if clarified, may allow interventions toward prevention. We systematically reviewed the literature concerning season-of-birth and bipolar disorder and depression and explored associations between the perinatal natural photoperiod and these outcomes in a cross-sectional analysis of the UK Biobank database. We used mean daily photoperiod and relative photoperiod range (relative to the mean) in the 3rd trimester and, separately, in the first 3 months post birth as metrics. From review, increased risk of depression with late spring birth is compatible with increased odds of probable single episode-, probable recurrent-, and diagnosed depression (OR 2.85 95 %CI 1.6-5.08, OR 2.20 95 %CI 1.57-3.1, and OR 1.48 95 %CI 1.11-1.97, respectively) with increasing 3rd trimester relative photoperiod range for participants who experienced relatively non-extreme daily photoperiods. Risk of bipolar disorder with winter-spring birth contrasted with no consistent patterns of perinatal photoperiod metric associations with bipolar disorder in the UK Biobank. As natural photoperiod varies by both time-of-year and latitude, perinatal natural photoperiods (and a hypothesized mechanism of action via the circadian timing system and/or serotonergic circuitry associated with the dorsal raphe nucleus) may reconcile inconsistencies in season-of-birth associations. Further studies are warranted.

A Machine-Learning-Algorithm-Based Prediction Model for Psychotic Symptoms in Patients with Depressive Disorder

Psychotic symptoms are rarely concurrent with the clinical manifestations of depression. Additionally, whether psychotic major depression is a subtype of major depression or a clinical syndrome distinct from non-psychotic major depression remains controversial. Using data from the Research on Asian Psychotropic Prescription Patterns for Antidepressants, we developed a machine-learning-algorithm-based prediction model for concurrent psychotic symptoms in patients with depressive disorders. The advantages of machine learning algorithms include the easy identification of trends and patterns, handling of multi-dimensional and multi-faceted data, and wide application. Among 1171 patients with depressive disorders, those with psychotic symptoms were characterized by significantly higher rates of depressed mood, loss of interest and enjoyment, reduced energy and diminished activity, reduced self-esteem and self-confidence, ideas of guilt and unworthiness, psychomotor agitation or retardation, disturbed sleep, diminished appetite, and greater proportions of moderate and severe degrees of depression compared to patients without psychotic symptoms. The area under the curve was 0.823. The overall accuracy was 0.931 (95% confidence interval: 0.897-0.956). Severe depression (degree of depression) was the most important variable in the prediction model, followed by diminished appetite, subthreshold (degree of depression), ideas or acts of self-harm or suicide, outpatient status, age, psychomotor retardation or agitation, and others. In conclusion, the machine-learning-based model predicted concurrent psychotic symptoms in patients with major depression in connection with the "severity psychosis" hypothesis.

Birth Month and Course of Recurrent Depressive Disorders in a Polish Population

BACKGROUND The aim of this study was to determine whether the specific season of the year during which the first trimester of pregnancy takes place is significantly associated with the course (intensification and frequency of occurrence) of an episode of recurrent depressive disorder in adult life. MATERIAL AND METHODS We enrolled 184 patients treated for recurrent depressive disorders. RESULTS An analysis of the results obtained indicates that the greatest number of people suffering from a major depressive episode were born in the spring and summer (from April to September), meaning that the first trimester of pregnancy occurred between October and March. However, our results were not statistically significant, perhaps due to the small size of the examined group. CONCLUSIONS The results obtained indicate that birth month may be significantly associated with the course of recurrent depressive disorders. In patients from Central Europe, the first trimester of pregnancy falling in autumn and winter seems to be significant. These results need to be interpreted with caution due to the small size of the examined group.

Potential Relationship between Season of Birth and Clinical Characteristics in Major Depressive Disorder in Koreans: Results from the CRESCEND Study

We aimed to examine the potential relationship between season of birth (SOB) and clinical characteristics in Korean patients with unipolar non-psychotic major depressive disorder (MDD). Using data from the Clinical Research Center for Depression (CRESCEND) study in South Korea, 891 MDD patients were divided into two groups, those born in spring/summer (n=457) and those born in autumn/winter (n=434). Measurement tools comprising the Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale, Brief Psychiatric Rating Scale, Scale for Suicidal Ideation, Clinical Global Impression of severity, Social and Occupation Functional Assessment Scale, WHO Quality of Life assessment instrument-abbreviated version, Alcohol Use Disorder Identification Test, and Temperament and Character Inventory were used to evaluate depression, anxiety, overall symptoms, suicidal ideation, global severity, social function, quality of life, drinking, and temperament and character, respectively. Using independent t-tests for continuous variables and χ² tests for discrete variables, the clinical characteristics of the two groups were compared. MDD patients born in spring/summer were on average younger at onset of first depressive episode (t=2.084, p=0.038), had greater loss of concentration (χ²=4.589, p=0.032), and were more self-directed (t=2.256, p=0.025) than those born in autumn/winter. Clinically, there was a trend for the MDD patients born in spring/summer to display the contradictory characteristics of more severe clinical course and less illness burden; this may have been partly due to a paradoxical effect of the 5-HT system.

No differences between drug naive and drug experienced unipolar depressed patients in terms of neurobiological testing: a cross sectional study

Successful antidepressant treatment has been associated with concomitant changes in brain function, consolidated as long as treatment is continued and remission is preserved. The present study aimed at assessing the impact of prior antidepressant treatment on brain function in currently depressed but unmedicated individuals by investigating for any differences between antidepressant-naïve vs. antidepressant-experienced subjects. Fifty right-handed patients (22 medication-naïve vs. 28 medication-experienced), suffering from major depression participated in the study. They all underwent a standardised clinical interview and psychometric assessment combined with neurobiological tests (brain SPECT, Dexamethasone Suppression Test, Dexfenfluramine Challenge Test, electro-oculogram, flash-electroretinogram and flash-visual evoked potentials and pattern-reversal visual evoked potentials). No significant differences between medication-naïve and medication-experienced depressed subjects were found in terms of the neurobiological markers assessed, after controlling for age, sex, age at onset, number of depressive episodes, depression subtype (melancholic, atypical or undifferentiated) and severity of current episode. Unmedicated currently depressed patients, no matter their previous exposure to antidepressants, show similar changes in brain function. This does not necessarily mean that antidepressants do not have a long term effect on brain physiology, since not all patients relapse. However, it seems that those patients who relapse after stopping medication, seem to 'regress' to an 'as if never medicated' state, with regard to brain function. These findings might suggest that continuous maintenance treatment with antidepressants is essential for patients at high risk to relapse. Alternatively, they might suggest that our methodology assesses only a shallow and mainly state part of the pathophysiology of depression.

Season of birth is associated with adult body mass index in patients with bipolar disorder

Cardiovascular risk factors, such as abdominal obesity and obesity in general, are very prevalent among patients with bipolar disorder (BD). Although long-term use of psychotropic medications is an important determinant of these risk factors, other evidence suggests that early development may interact with the mood disorder diathesis to exponentially increase the risk of obesity. The goal of our study was to test whether season of birth is associated with adult body mass index (BMI) and abdominal obesity in individuals with bipolar disorder. We compared season of birth effects on BMI in 375 adult patients with bipolar disorder and 196 adult patients with unipolar major depression. We found a significant season of birth effect on BMI in patients with bipolar disorder, but not unipolar. In patients with bipolar disorder, season of birth was also associated with waist circumference, with a stronger effect in males. Season of birth affects adult BMI and waist circumference in patients with bipolar disorder, but not in patients with unipolar depression. Our results suggest that early environmental factors, yet to be identified, interact with specific neurobiological features of bipolar disorder to determine stable traits and disease risk factors in adult life.

Influence of photoperiod on hormones, behavior, and immune function

Photoperiodism is the ability of plants and animals to measure environmental day length to ascertain time of year. Central to the evolution of photoperiodism in animals is the adaptive distribution of energetically challenging activities across the year to optimize reproductive fitness while balancing the energetic tradeoffs necessary for seasonally-appropriate survival strategies. The ability to accurately predict future events requires endogenous mechanisms to permit physiological anticipation of annual conditions. Day length provides a virtually noise free environmental signal to monitor and accurately predict time of the year. In mammals, melatonin provides the hormonal signal transducing day length. Duration of pineal melatonin is inversely related to day length and its secretion drives enduring changes in many physiological systems, including the HPA, HPG, and brain-gut axes, the autonomic nervous system, and the immune system. Thus, melatonin is the fulcrum mediating redistribution of energetic investment among physiological processes to maximize fitness and survival.

Association between affective temperaments and season of birth in a general student population

BACKGROUND

Several studies indicate a significant association between birth season and personality and neuropsychiatric disorders. The aim of our present study was to investigate the association between affective temperaments and season of birth in a nonclinical sample.

METHODS

366 university students completed the standardized Hungarian version of the Temperament Evaluation of Memphis, Pisa, Paris and San Diego-Auto-questionnaire (TEMPS-A). Ordinary Least Squares regression was applied to explain the relationship between TEMPS-A subscale and birth season of the respondents.

RESULTS

We found a significant association between temperament scores and birth season in the case of the Hyperthymic, Cyclothymic, Irritable and Depressive temperaments, while no significant results emerged for the Anxious temperament.

LIMITATIONS

The relatively small sample size, especially in the case of seasonal and monthly subsamples limits generalization of our results.

CONCLUSIONS

Our results support the evidence that there is a strong association between season of birth and personality, extending the results to affective temperaments as well. Furthermore, our results are in line with clinical observations concerning the seasonal variation of onset and hospitalization due to affective episodes. This is especially important, since affective temperaments are conceived as the subaffective and subclinical manifestations of major and minor affective disorders indicating a risk for the development of these disorders and also exerting a possible pathoplastic effect, thus our results also have clinical significance.

Revisiting the Dexamethasone Suppression Test in unipolar major depression: an exploratory study

BACKGROUND

Important methodological questions still exist concerning the Dexamethasone Suppression Test (DST), including the possibility of a better way of interpreting it. The aim of the present study was to explore the feasibility of an alternative way of interpreting DST results.

METHODS

A total of 50 patients with major depression aged 41.0 +/- 11.4 years old participated in the study. Past and present suicide attempts were recorded. Psychometric assessment included the Hamilton Depression Rating Scale (HDRS), the Hamilton Anxiety Scale (HAS), the Newcastle Depression Diagnostic Scale (NDDS), the Diagnostic Melancholia Scale (DMS) and the General Assessment of Functioning (GAF) scale. The 1 mg DST protocol was used. Analysis methods included the chi square test and analysis of covariance (ANCOVA) with Fisher least significant difference (LSD) as post hoc tests.

RESULTS

In all, 34 patients (68%) were suppressors, 16 (32%) were non-suppressors and 14 patients had cortisol values above 5 microg/dl at baseline. Baseline cortisol level did not influence the classical DST interpretation. A total of 18 patients (36%) showed an increase of their cortisol levels after dexamethasone administration and 32 patients (64%) showed a decrease. Reducers had less melancholic features, similar levels of depression, better sleep and less suicidal thoughts in comparison to increasers. No relationship of DST to suicidality was found.

DISCUSSION

The present study explored the pattern of cortisol response to dexamethasone suppression and suggested an alternative way of coding and interpreting the DST on the basis of whether the cortisol levels remain stable or increase vs decrease after the administration of cortisol. The results put forward a complex way of understanding the relationship of the DST results with clinical symptoms.