Seasonality in cognitive and emotional endophentypes

Proposal details

Title: Seasonal patterns in endophenotypes for suicidal behaviour
Research Area(s): Thinking and Cognition
Emotion and Self Regulation
Background: Suicide is a major public health problem with more than 800 000 suicides worldwide every year. Numerous studies have observed that the incidence of suicide follows a seasonal variation, with a peak during spring or early summer. Evidence has further suggested environmental influences, such as sunshine or temperature exposure, as triggers for suicidal acts. Vulnerability for suicidal behaviour has moreover been linked to underlying genetic factors, harbouring the potential to interact with the environment and the individual epigenetic profile. This may result in the modulation of neuronal circuits and neurocognitive alterations, manifesting as specific cognitive endophenotypes connected to personality characteristics such as aggression, impulsivity and impaired decision making, which are currently the most robust endophenotypes for suicidal behaviour. However, whether or not the amplitude in terms of expression of such traits follow the seasonal variation suggested for suicide incidence is yet to be examined. Elucidating such potential variability may provide an improved understanding of suicidal vulnerability, where measurable cognitive endophenotypes may serve as future targets of long-term therapeutic interventions.
Aims: To identify potential seasonal variation of cognition implicated in vulnerability to impulsive behaviour among healthy individuals and individuals with underlying clinical disorders. Specifically, we want to examine on a group level if is there higher prevalence of impulsive traits during spring and summer and if this association is different among those with and without psychiatric disorders.
Method: The seasonality patterns will be explored graphically, with simple tabulations by season and month and more specific circular tests for seasonality like Walter-Elwood test. These tests will be performed in different strata of healthy people, people with history of suicide attempt and a psychiatric disorder.