Past research indicates that the brain’s interoceptive network—the circuitry that supports our conscious and subconscious awareness of internal bodily sensations—may be factors in depression and anxiety. Specifically, it has been proposed that in depression and anxiety disorders, some individuals may misinterpret internal bodily signals such as heartbeat or breathing sensations, misperceptions that in turn may be involved in symptoms such as withdrawal and avoidance.

A research team led by 2003 BBRF Young Investigator grantee Tony T. Yang, M.D., Ph.D., of the University of California, San Francisco, recently reported on results of a clinical trial that addressed this possibility. They tested the idea that by increasing “interoceptive awareness”—individual awareness of internal bodily states—via a strengthening of connectivity within the brain network that processes interoception, young people might more accurately interpret interoceptive signals, perhaps yielding better engagement with other people and the surrounding environment.

Dr. Yang and colleagues focused specifically on interoception in adolescents aged 14-18, noting that over 62% of those who develop psychiatric disorders do so before they reach the age of 25. The hypothesis of  an association between the interoceptive brain network and positive mental health was supported, they said, by past research showing that the volume of grey matter (the nerve cells of the brain) in a key interoceptive region called the insula is positively associated with subjective well-being, as well as a study finding that “mindfulness” improved well-being and targeted interoceptive brain regions.  Mindfulness is a state of active, open attention to the present, of observing one's thoughts and feelings without judging them.  

“Mindfulness practices involve closely attending to the body and breathing,” the team noted in its paper, appearing in Frontiers in Psychology.  Such practices, they said, “may remodel large-scale brain networks,” as well as reduce activation in the brain’s default-mode network (DMN), which tends to be overactive in people who are depressed.  

The team conducted a randomized controlled clinical trial gauging the impact of a mindfulness-based intervention on brain networks and on mental health in a cohort of healthy adolescents. The intervention, called TARA (Training for Awareness, Resilience, and Action), was originally developed by Dr. Yang and Dr. Eva Henje at UCSF to treat adolescent depression by targeting neurocircuitry involved in adolescent development and depression, including the striatum and regions involved in interoception.  A 12-week intervention, TARA incorporates mindfulness-based practices including breathing techniques, yoga-based movements, guided meditation (such as interoceptive/sensory awareness practices called “body scans”), and psychoeducation.

The team recruited 100 unmedicated young people without psychiatric diagnoses (considered “healthy” for purposes of the trial) from the San Francisco Bay area, half of whom were randomly assigned to receive TARA and half, placed on a waiting list, who did not receive the intervention. 94 of the participants completed the 12-week study; about 57% of the original cohort was female and the average age was about 16. At baseline and at the conclusion of the trial each participant received a functional MRI brain scan and assessment of emotional symptoms. The investigators, but not the participants, were “blinded” as to which groups the participants had been randomly assigned.

TARA consists of 4 “modules,” each lasting 3 weeks: the first aims to promote activation of the vagus nerve and the senses through breathing practices and slow synchronized movement; the second involves noticing negative self-referential thinking and shifting to present-moment sensory and interoceptive awareness; the third aims to bring these skills to managing emotions during social interactions; the fourth aims to increase behavioral responses guided by “intrinsic reward,” seeking to decrease avoidance, increase committed action, and improve behavioral effectiveness in times of emotional disturbance.

Importantly, TARA was administered entirely via the internet, with 90 minutes per week (18 hours total) of therapy sessions delivered by two facilitators via Zoom. Suggested weekly home practice could last anywhere from 5 minutes to 1 hour.  

Post-trial analysis showed that TARA “significantly changes” structural brain networks in adolescents, “with related improvements in well-being outcomes.” The team found that many brain regions involved in interoception, emotion regulation, and mindfulness that related to emotional well-being and sleep quality had “significantly changed structural connectivity” following TARA. Further, a whole-brain network related to adolescent interoception showed significant strengthening among those who received TARA (compared with those who didn’t). These changes were related, in the team’s view, to improvements in sleep quality. Mindfulness practices such as TARA which improve sleep quality, the team said, call attention to the integrity of white matter networks in young people. White matter refers to axons which connect the neurons that comprise much of the brain’s grey matter.  

“Together these results point to TARA’s targeted effect in adolescent cortical and subcortical networks involved in mindfulness and interoception,” the team concluded. They also said that the trial demonstrated the feasibility of using secure telehealth platforms and online electronic data capture systems to fully deliver the intervention remotely to adolescents, who found it tolerable and easy to use.

One specific finding was that increased connectivity strength in the brain’s right insula was associated with improvement in emotional well-being in those who received TARA. Such improvements in well-being were not solely related to strengthening in the interoceptive network, however; they may be related to stronger connection between the insula and other brain regions outside the interoceptive network. The team also noted that improvements in emotional well-being might be associated with other processes not affected by TARA.  

“TARA may be a useful intervention to support adolescent brain development to improve sleep and emotional well-being” the team said. Particularly important, they said, was the possibility of offering a “fully remotely delivered and neuroscience-based mindfulness intervention” such as TARA to young people living across diverse urban and rural areas, extending the reach of neuropsychiatry. Adolescence is a vulnerable neurodevelopmental phase with significantly increased risk for development of mental health disorders. It is also “an ideal period” in which to intervene, they said, due to the increase in neural plasticity that characterizes the adolescent years, presenting the possibility of inducing greater changes in brain networks compared with later periods of life.