Functional Near-infrared Spectroscopy for Anxiety Monitoring and Neurofeedback.

Clinical Evaluation of Functional Near-infrared Spectroscopy for Anxiety Monitoring and Neurofeedback.

The objective of this subproject is to validate the efficacy of the fNIRS real-time anxiety monitoring and neurofeedback system. In the first year, the cerebral hemodynamics measured by commercial fNIRS during resting state and cognitive tasks from 60 generalized anxiety disorder (GAD) patients and 30 healthy subjects will be processed and analyzed using AI algorithms. The novel anxiety fNIRS biomarker will be identified and correlated to clinical anxiety scales (such as HARS and STAI). In the second year, the reliability, validity, and responsiveness of the AI-fNIRS biomarker will be validated. The accuracy of using AI-fNIRS biomarker to predict the diagnosis of GAD (according to DSM-5) and anxiety rating scales will be calculated from 60 GAD patients and 30 healthy subjects. In the third year, a neurofeedback method using AI-fNIRS biomarkers to guide digital cognitive behavior therapy (dCBT) through visual/audio cues will be developed. A pilot study with 12 GAD patients will be performed to test the feasibility of mindfulness training during AI-fNIRS neurofeedback. In the fourth year, a large scale RCT will be performed to validate the therapeutic efficacy of AI-fNIRS neurofeedback dCBT in 40 patients with GAD. The protocol of using real-time AI-fNIRS biomarkers as a neurofeedback to augment mindfulness training will be optimized according to previous year.

The feedback group will get real neurofeedback about changes in anxiety-related cerebral hemodynamics. AI-fNIRS neurofeedback will be provided 3 times a week, for a total of 4 weeks.

The sham group will be shown playbacks of someone's real feedback sessions. Sham AI-fNIRS neurofeedback will be provided 3 times a week, for a total of 4 weeks.

The device, with AI-fNIRS signals serving as brain monitor to indicate the level of anxiety, provides mindfulness training through visual and auditory cues to help participants modulate their brain activity, and thus alleviates anxious states.

The sham control consists of playbacks of someone else's real AI-fNIRS neurofeedback and will be provided 3 times a week, for a total of 4 weeks.

fNIRS is an optical brain monitoring technique. It serves as an ideal tool to record brain activities based on hemodynamics during various cognitive or motor tasks. The regions of interest are bihemispheric prefrontal cortices.

Change in severity of physiological and psychological anxious symptoms as assessed by Hamilton Anxiety Rating Scale (HARS)

Hamilton Anxiety Rating Scale (HARS) is a frequently-used scale in clinical psychiatric fields to assess the severity of anxious symptoms. Conducted by well-trained clinicians, HARS consists of 14 items and can be classified into 2 domains: physiological and psychological anxious symptoms. The minimum and maximum values are 0 and 56 respectively, with higher scores represent worse outcomes.

State-Trait Anxiety Inventory (STAI) is a self-report measure of subjective feelings of anxiety. It consists of 2 subscales: state and trait anxiety, with the former characteristic of temporary states of emotion and the latter dealing with the frequency of anxiety and other related emotion in general conditions. The minimum and maximum values of each subscale are 20 and 80 respectively. The higher the score, the higher the level of anxiety.

VAS is a self-report measure. Participants are required to draw a 10 cm line representing their anxiety spectrum, and mark their subjective feelings of anxiety level on it, with the highest on the right end.

Measured with Apple Watch, HRV serves as a physiological index of anxiety. Subjects with anxiety will show lower HRV than healthy individuals.

Sixty words related to either positive, neutral or negative emotion are displayed in various colors in the emotional Stroop task. Participants are required to read out the color of each word as accurately and quickly as possible. The differences in reaction rate between negative emotion and the two other conditions indicate to what extent participants are affected by emotion.

Two images are first displayed on the left and right sides respectively and randomly, with one related to negative emotion and another related to neutral emotion. After the images disappear, a dot pops up on either side at random. Participants are required to indicate the direction where the dot showing up by pressing the button as soon as possible. The difference in reaction rate between the negative and neutral emotional images represents the extent to which the participants are influenced by emotion.

PSQI is a self-report measure of sleep quality. It consists of 9 items and is related to 7 dimensions of sleep. The higher the score is, the worse the quality of sleep.

BDNF, a protein of the highest content in the brain, promotes neuron growth and synapse formation. Its secretion is inhibited under stress or depression; accordingly, BDNF serves as a biological index of aforementioned conditions.

IL-6 is a proinflammatory cytokine and capable of modulating immune and inflammatory response. The level of IL-6 is elevated under stress, depression, etc. and hence serves as an indicator of such conditions.

Inclusion Criteria: Being diagnosed with generalized anxiety disorder (GAD) by psychiatrists based on DSM-V. Native Chinese speakers. Right-handers. Normal vision without or after correction. Normal hearing and verbal expression. Regular returns of medical or psychological intervention during participation. Exclusion Criteria: Being diagnosed with other major neurological or mental disorders.