“Emotion is a complex psychological phenomenon, which occurs as animals or people live their lives. Emotions involve physiological arousal, appraisal of the situation, expressive behaviors, and conscious experience. Emotion is associated with feeling, mood, temperament, personality, disposition and motivation.” This definition by Plutchik1 indicates the high relevance of emotions for basic as well as clinical research in neuroscience and psychiatry.

In this issue of Dialogues in Clinical Neuroscience, the complex topic of emotion(s) is tackled from different perspectives, represented in eleven contributions. Each paper reflects a unique approach to understanding emotions and their role in etiology, diagnosis, and treatment of psychiatric disease.

In his State of the art paper, Jaak Panksepp (p 363) criticizes preclinical animal models, which reflect behavior only. The neglect of animal emotions might explain the lack of novel targeted treatments despite decades of intensive research. He describes how the use of “affective-neuroscience”-based animal modeling, particularly considering the rewarding and punishing aspects of emotion, has resulted in the development of three promising novel antidepressants.

In the Translational research section, Paul Gilbert (p 381) highlights the relevance of an evolutionary approach and suggests integrating the effects of threat processing on prosocial interactions into psychiatric formulations and interventions. Insight into the coregulating processes of motives and emotions, especially prosocial ones, might offer a better understanding of mental health difficulties. In a further article in this section, Adam Kepecs and Brett Mensh (p 391) explore the relationships between subjective feelings and their underlying brain circuits from a computational perspective. They apply systems neuroscience to the study of emotions, and suggest that emotions are the product of neural computations whose motor role is reallocating bodily resources gated by smooth muscles. They illustrate this framework with recent investigations on confidence.

Clinical research is presented in the following seven manuscripts. Leah Somerville et al (p 403) focus on the enormous changes in emotional behavior during adolescence, on psychological and neurobiological development, and on the underlying mechanisms intensifying the risk of psychopathology. Jorge Moll et al (p 411) describe a “provisional taxonomy” of moral emotions and their neural underpinnings, and discuss how disgust, guilt, shame, or embarrassment can be implicated as key affective experiences in psychiatric diagnoses. Alan Anticevic et al (p 421) highlight in particular emotional dysregulation in schizophrenia and major depressive disorder, namely, deficits in hedonic and anticipatory behavior to pursue a rewarding outcome. They describe unique disturbances in each disorder involving dissociable neural systems and interactions between affect and cognition. Mark Leary (p 435) emphasizes the importance of rejection as a threat to acceptance and belonging for human emotion, and examines seven emotions such as hurt feelings, jealousy, shame, guilt, and loneliness regarding their evolutionary functions and neuroscientific mechanisms. Facial expression is the topic of two papers: Aleix Martínez and Shichuan Du (p 443) studied facial expressions observed when people experience “compound emotions.” They have identified seventeen compound facial expressions consistently produced across cultures, and they discuss the implications for psychopathology research. Karsten Wolf (p 457) focusses on methods of assessing facial expression, and illustrates the latest developments in the field of automated computerized facial recognition, which allows real-time identification of facial expression in social environments. The final clinical paper, by Peter Kirsch (p 463), summarizes the vast recent research on oxytocin, an important modulator of emotional processes, including, among others, bonding, empathy, and interpersonal trust. Impairments in these social domains might be relevant for disorders such as autism, social anxiety, or schizophrenia.

The final paper of this issue, a Pharmacological aspects article, is of particular psychopharmacological interest. Catherine Harmer and Abbie Pringle (p 477) describe how antidepressants modulate emotional processing in healthy volunteers, and suggest that such human models might be useful to test the efficacy of novel treatments and to match these treatments to individual patients or subgroups of patients.

The coordinators of this issue are confident that the reader will find many fascinating and original ideas in all these papers on a very complex topic. This rather stimulating information will hopefully broaden his/her perspective and lead to further promising research!

REFERENCES
1. Plutchik R. The nature of emotions. American Scientist. 2001;89(4):344.

Dieter Naber, MD; David R. Rubinow, MD