MILGЯAM

They both focus on the psyche of each character showcased within an episode. 

Both are amazing animated music video series' on Youtube, with plot and characters developed through music and lyrics, as well as visual graphics that correlate with the songs. The music videos leave you hooked for the next one, and the songs get you thinking about theories and interpretations of the story. 

Both anime are ones where the more invested you are into the hidden details, the more information you find, and the more pay-off you receive from a deeper, more nuanced narrative than expected. Both have narratives (and music videos) that connect to a deeper theme of corruption~ 

Both the Milgram series and Itte are some of my favorite 3-4 minute music videos ever. They explore extremely heavy themes in some of the most heartbreaking ways with some of the most emotional singing and lyrics I've heard. I don't want to spoil the themes, but they're extremely short so please give them a shot!  

Both have very subtle themes related to mental health in vastly different execution. Milgram is more of a murder mystery w/ a few red herrings (that don't have mental health issues) while Mushishi is extremely good at making its characters seem like they're at least 'okay' when all of them have something going on~ 

Both of these anime are centered around a trial that requires finding characters guilty or innocent based on somewhat cryptic hints.