these are all fantastic additions and i would like to add some as well!
its been a while since ive watched this series so i dont know how well ill be able to explain, but i have a lot of thoughts on this
all of them are either autistic, adhd, ocd, or a mixture (to me).
they all very much interact with each other and the world like autistic teenagers with varying and conflicting support needs, like the first reblogger added. there is an inherent understanding of each other but it can often get overshadowed when they have miscommunications or their traits clash.
michelangelo is sensory seeking, and typically more hyposensitive to his surroundings, but can be prone to outbursts of frustration or overstimulation pretty easily. he seems to have trouble regulating his emotional reactions, which can read as short, explosive meltdowns, or random bouts of crying. he is highly anxious despite his laidback personality. he also has a tendency to run away when this happens. he also is seen struggling with speech, mixing up words and syllables and figures of speech and stumbling over his words. he craves connection but often falls short in his interactions, missing social cues and body language. he also seems to have lower empathy, frequently struggling to understand people's motivations and the like, somtimes saying mean things without realizing (while having plenty of compassion and sympathy!) like stated above he also seems to have adhd- needing to make tasks fun and losing his train of thought being a big thing. big low masking audhd vibes.
raphael has extreme rejection sensitivity, and tendencies to cover feelings with humor (which can be a form of masking). he has trouble with sincreity, probably because he has trouble processing his emotions and being vulnerable. he internalizes things a lot and his self esteem is pretty low. he seems to have a special interest in pirates,comedy and detective work. he seems to have trouble reading when hes taking things too far. he also seems the most sensitive to stimuli out of them, being the pickiest eater and also occasionally being shown covering his ears when things go wrong. he often doesnt feel like he contributes anythng of value, and struggling to find his niche outside of 'funny guy', which to me indicates him being a high masking individual. hes quite high strung and tends to reign the rest of them back in (looking at you donatello) when he thinks the situation is ridiculous. big high masking audhder vibes.
leonardo is very routine oriented and hyper focused on rules. he has a way he does things and needs to do it that way. leonardo seems sensitive to stimuli as well, and his need for control could play into that. he is highly anxious and feels immense responsibility for his loved ones. he is shown to be highly empathetic, to his detriment at times. hes drawn to art, and literature, and gets extremly absorbed into tasks and activities and interests. he is very grounded in reality and direct in how he feels or thinks a situation should be handled. he gets extremely absorbed into tasks and activities (think Tempestra) to where he can't think about or do anything else. he reads as very ocd autistic to me. and a certified silly goose
donatello practically invented having a onetrack mind. his brain is constantly focused on a task. he gets so absorbed in what he's doing he can just Forget the outside world exists (given how many times hes shown being in his garage or lab for days on end) his hyperfocus is extreme and can cause him to neglect his needs, and make the others forget about his needs too because theyre so used to him constantly working. he has a flair for the dramatic, and will momologue if he sees fit. he can be incredibly blunt without realizing it and is also pedantic, which can be seen as rude or arrogant if you don't know. he seems to lack self preservation and sense of danger sometimes, specifically when it comes to his work. he's quite impulsive, and has a short fuse at times which can read as mini-meltdowns. he oftens laments their situation, and wishes he had a place in the world. he feels like an outcast. he often feels overworked and underappreciated. big depression-autism combo vibes.
all of them have a strong personal moral code, which can be great for their job but also be a detriment to them and cause arguments. (ie, raphael vs the volcano and like. all of red sky)
they all also seem to be picky in some way, having a common safe food of pizza. (donatello hates fish, leonardo hates broccoli, they all can't stand sushi, etc)
leonardo and michelangelo specifically stand out as either ocd or generalized anxiety coded to me. leonado probably seems obvious, due to his obessive fears of failure, extreme seperation anxiety, extreme snake phobia, and compulsive need to be in control, but michelangelo definitely seems to have some of the hallmark magical thinking aspects of primarily obsessional ocd (like thinking something will make it happen somehow) and also has voiced some pretty gruesome thoughts that can be read as intrusive. his distractability in red sky read to me as a worsening of ocd symptoms, (that whole episode where he would keep getting stuck on stuff and seemed super preoccupied specifially) and also a regression of autism and adhd. both of them are seen having anxious spirals, either internally or externally (example, take me to your leader for leonardo and bebop and rocksteady conquer the universe for michelangelo) which can read as panic or anxiety attacks. an important thing to note about ocd is that compulsive behaviors arent always visible.
im sure theres more stuff i could say but again it's been a while and i also have Big Problems thinking and explaining