Because of their potential to enhance pathways for diagnosis and treatment, a great deal of research has been conducted to identify brain biomarkers of mental illnesses such as depression and anxiety. Similarly, the investigation of the biomarkers of those protective factors that help individuals resist, or recover from, these mental illnesses is also directly relevant to clinical practice. One such protective factor is Psychological Resilience (PR) but relatively little is known about its neurobiological underpinnings. A literature search was conducted of electroencephalographic data and PR, revealing seven studies that reported brain electrical activity categorised into bands of specified frequencies. Several studies reported significant associations between PR and alpha band activity, and somewhat less on beta band activity, principally via their roles in emotion regulation and problem solving. However, despite having a major role in many aspects of cognition and brain function, and being implicated in depression, only two studies examined gamma band activity specifically, and their results were equivocal. Several possible reasons for these apparently null results of the association between gamma band activity and PR are discussed, leading to a brief description of gamma, and suggestions for future research into its association with PR.

This review raises the importance of understanding the functions of gamma waves in the practice of clinical psychiatry. Measured by electroencephalograph (EEG), gamma waves are those electrical waves between 30 Hz and 200 Hz, and are relevant to psychiatry because of their ability to influence other brain electrical activity, and thence have associations with various mental disorders. To inform readers, gamma waves are defined and described, and some examples of their association with psychiatric disorders are briefly recounted. Four ways in which gamma waves might modulate brain activity and influence behaviour, potentially leading to a comprehensive model of gamma and its association with mental illness, are discussed. Inconsistencies in definition, measurement, and findings from gamma wave research are also described, and suggestions made for overcoming these limitations in future research.