"Depression and anxiety are more than just imbalanced neurotransmitters, they are just as much imbalanced neuro-circuits (the wiring in the brain), overactivity in a circuit called the default mode network floods our conscious thinking mind with depressive thoughts and intrusive anxious thoughts Is your mind constantly thinking about your shortcomings, failings, faults, mistakes and things that make you anxious? If it is an overactive default mode network may be a root cause of the problem. The good news is we can train our brain to switch off overactivity in the default mode network"

"Some neural networks take longer to develop or may be less efficient in kids with ADHD. One example is the “default mode network.” It plays a key role in resting the brain. In kids with ADHD, the brain takes longer to “switch off” activity in the default mode network when they need to focus on something. ADHD affects other pathways too, like the fronto-parietal network. It plays a key role in making decisions and learning new tasks. (That’s why it’s often called the “executive control circuit.”) Differences in this and other neural networks may help explain ADHD symptoms like mind-wandering and trouble with impulse control."

"The Default Mode Network (DMN) has been found to be involved in various domains of cognitive and social processing. The present article will review brain connectivity results related to the DMN in the fields of social understanding of others: emotion perception, empathy, theory of mind, and morality. Most of the reviewed studies focused on healthy subjects with no neurological and psychiatric disease, but some studies on patients with autism and psychopathy will also be discussed. ...These results indicate that the DMN is indispensable in the social understanding of others."

"Patients with borderline personality disorder (BPD) present dysfunctions of the default mode network (DMN). Mindfulness training has proven effective to improve the symptoms of BPD. The present study examines the effect of mindfulness training on BPD symptomatology and DMN activity during the performance of a working memory task in patients with BPD. Sixty-five individuals with BPD were randomized to receive psychotherapy with either the mindfulness module of dialectical behavioural therapy (DBT-M) or with interpersonal effectiveness module (DBT-IE). The impact of treatments was evaluated with clinical and mindfulness variables as well as with functional magnetic resonance imaging during performance of the task. Both groups showed improvement in BPD symptoms and other clinical variables after treatment. Unexpectedly, there were no between-group differences in DMN activation or deactivation. However, activation of the left anterior insula increased in both groups after the intervention. Compared with the control group, participants in the DBT-M group presented higher deactivation in a cluster extending bilaterally from the calcarine to the cuneus and superior occipital gyri."

"Borderline personality disorder (BPD) is a severe mental disorder, characterized by a pronounced instability in affect, cognition, interpersonal relationships, and behavior. Over the last decade, the understanding of possible neurobiological underpinnings of BPD has increased rapidly. There is growing consensus that mental disorders might be better understood in terms of network dysfunction, including functional and structural alterations in large-scale intrinsic brain networks. In this chapter, we give an overview over recent neuroimaging research in BPD, focusing on magnetic resonance imaging (MRI) studies. 

Converging evidence suggests disturbances in default-mode and salience network regions and in a corticolimbic circuitry involving the amygdala, hippocampus, insula, anterior cingulate, orbitofrontal cortex, and medial prefrontal cortex in BPD. These alterations may underlie clinical symptoms such as the marked expressions of emotion dysregulation, impulsivity, and interpersonal disturbances in individuals with the disorder. It remains an important topic for future research to clarify whether these structural and functional abnormalities are specific to BPD or related to other factors, such as a history of traumatic events in childhood. Given the complexity of BPD psychopathology, combining multiple measures in research may help to enhance the understanding of possible underlying mechanisms."

Trauma

"Trauma affects our ability to be in contact with our sense of self through both cognitive (top-down) and somatic (bottom-up) processes. People with trauma report this clearly in phrases Lanius documents in her article such as: ‘I do not know myself anymore,' ‘I will never be able to experience normal emotions again,' and ‘I feel dead inside.' There is a growing body of research that supports the role of three large-scale brain systems in emotional regulation capacity and mental health. These are: the Default Mode Network (sense of self when quiet), Salience Network (system of importance and relevance), Cognitive/Executive Network (top-down integration of meaning and affect). 

The Default Mode Network is active during self-referential, autobiographical processing of memories and creates what Winnicott called the ‘sense of going on being' when there is continuity in the network over time. For individuals with trauma, the resting state Default Mode Network shows significant reductions in system connectivity, indicating a disruption to the sense of self and feeling of continuity in time. This relates in many ways to the relationship between under-coupling and freeze states discussed in the SE theory."