Investigating Depression Vulnerability with Music
Sabine Aust & Malek Bajbouj
Department of Psychiatry and Psychotherapy Charité University Medicine Berlin
As estimated by the World Health Organization (WHO), major depression will become one of the main causes of premature death and disability by the year 2020. The disorder is characterized by discrete, recurrent episodes of low mood with a variety of affective symptoms such as anhedonia, feelings of helplessness and worthlessness, suicidal ideation, as well as low motivation and anergia. In recent years, a large number of studies have investigated neural and behavioral correlates of depressive symptoms, leading to a better understanding of acute episodes of depression and potential mechanisms of change. However, with regard to increasing prevalence, identifying valid risk factors of major depression has become a major topic in psychiatry research. As proposed in the so-called “vulnerability-stress models”, a variety of biological, interpersonal and environmental factors contribute to the development of major depression. Consequently, investigating the neural underpinnings of these risk factors has become necessary to provide critical insight into the development, the course and the nature of the disorder.
To do so, a number of recently published articles have drawn their attention to individuals with a history of depression, who are currently euthymic, but show an increased risk of major depression due to previous episodes. Given the current state of knowledge, remitted depression is associated with a selective deficit in cognitive control over sad stimuli, higher self-reported negative affect in response to stress, and neural alterations in the processing of social interaction scenes. These behavioral and neurobiological markers are partly modulated by personality traits such as neuroticism or anxiety and are supposed to regulate an individual’s vulnerability to major depression.
But what about emotional factors? It is obvious that major depression has a considerable impact on how emotions are experienced, with anhedonia being one of the most prominent and straining symptoms. A new approach to directly investigate an individual’s ability to experience positive emotions and its neural correlates can be taken by the use of music. Music is a powerful stimulus to induce “real life” emotional states and has previously been shown to elicit strong responses in limbic structures of the healthy human brain, such as amygdala, hippocampus, anterior cingulate, parahippocampal gyrus and insula. A recent study addressed neural correlates of musically induced emotional experiences in individuals at risk for major depression to identify potential vulnerability markers of depression in the emotion-experiential domain. Using Irish dances, classical music and Jazz tunes, pleasant emotional states were induced in the participants while recording brain responses via functional magnetic resonance imaging (fMRI). The results revealed that the pregenual anterior cingulate cortex, a small emotion regulating brain structure, part of the limbic system and rich in serotonin transporters, was less responsive to pleasant music in individuals with a history of depression when compared to closely matched healthy control participants. Interpersonal factors such as trait anxiety or coping style were able to explain this hypoactivity. Interestingly, on a behavioral level, individuals at risk did not show any alterations with regard to their experienced emotions when listening to the joyful tunes: they reported similar levels of pleasantness, joy and arousal as the healthy, never depressed control group.
The main conclusion of the study is that pregenual anterior cingulate cortex reactivity in response to joy inducing music can be interpreted as a “neural marker” for depression vulnerability. Future studies are, of course, necessary to clarify whether the authors found a real biomarker or whether these alterations in brain function rather occurred as a consequence of recurrent episodes of major depression. However, beside this remaining question, the use of music in neuropsychiatric investigations seems a promising approach to bridge the gap between the arts, affective neuroscience and psychiatry and, finally, to take experimental lab conditions one step closer to real life.
Aust, S., Filip, K., Koelsch, S., Grimm, S., & Bajbouj, M. (2013). Music in depression: Neural correlates of emotional experience in remitted depression. World Journal of Psychiatry, 3(2), 8-17. Available online: http://www.wjgnet.com/2220-3206/full/v3/i2/8.htm or DOI: http://dx.doi.org/10.5498/wjp.v3.i2.8
Similar Methodological Approach:
Aust, S., Alkan Härtwig, E., Koelsch, S., Heekeren, H. R., Heuser, I., & Bajbouj, M. (2013). How emotional abilities modulate the influence of early life stress on hippocampal functioning. Social Cognitive and Affective Neuroscience, epub ahead of print. Available online: http://scan.oxfordjournals.org/content/early/2013/06/18/scan.nst078.long or DOI: http://dx.doi.org/10.1093/scan/nst078