Hierarchical Bottom-up insufficiency. As well as reduced plasticity inducing maladaptation mismatch and increase free energy between computing occurrences in the executive network  and their internal representations of the Default-mode network     
Imaging will involve the Executive Network and Default Mode Network and should be assessed over-time, and a free-energy delta distance (Humming distance like measure) is expected to increase. Correlation matrices and graph analysis will show reduced connectivity to the dorsolateral prefrontal areas. Treatment will have to reconnect prefrontal networks and increase plasticity.
Traditionally Serotonin Specific Reuptake Inhibitors (SSRI’s) are administrated also theoretically consider alternative (enhancing) neuronal-plasticity induction using cortical transcranial Magnetic Stimulation (TMS) transcranial Direct Current Stimulation tDCS, transcranial random Direct Current Stimulation trDCS. Additionally, consider Cognitive Behavioural Therapy like (CBT-like) personalized Virtual-Reality (VR) interventions. Use any intervention that will increase plasticity and reduce free energy. For Avolition consider modulating cortical hierarchical balance using transcranial Alternating Current Stimulation (tACS) to resynchronize unimodal and transmodal cortices and rebuilt hierarchal bottom-up (e.g., increase Gamma synchronization between parietal and prefrontal cortices). Consider adding Virtual Reality (VR)  prefrontal-cortical cognitive exercise for frontal cortical experience-plasticity-inducing environments (i.e., activating the plasticity of prefrontal cortex).