Max's past experience with trauma — namely, watching the Mind Flayer brutally kill her stepbrother Billy (Dacre Montgomery) in Season 3 — makes her a target for Vecna's manipulation. She's become withdrawn and adrift, pulling away from her friends and sinking deeper into what looks like depression.
Front and centre of this storyline, however, is Max (Sadie Sink), who, after her brother Billy's (Dacre Montgomery) death in the previous season, is suffering from grief and guilt, and the trauma of witnessing his death.
While there are no direct statements, it's still clear that Max suffers from mental illnesses, such as depression, trauma, and even PTSD.
What was Chrissy's Trauma? Chrissy's life appears to be free from flaws on the surface, but in reality, she is struggling terribly to conceal her depression and self-image stemming. She was struggling with these issues, which resulted in her developing an eating disorder due to her mother's verbally abusive comments.
Vecna's power not only takes a mental toll but also a physical one. Much like depression, Vecna's victims experience physical symptoms such as exhaustion, lack of sleep, headaches, and nosebleeds. Similarly, when dealing with depression and trauma, a person's physical health worsens.
Brenner (Matthew Modine) states in the Stranger Things episode "Papa" that Vecna "consumes" everything about his victims, Vecna targets traumatized victims because it builds for him a well of sad and angry memories to draw from. With each victim, he can become gradually more powerful.
Vecna lives in the Upside Down and preys on people's past traumas and guilt. The monster curses its victims, making them relive their trauma in progressively more gruesome ways until it violently kills them.
While intending to get his revenge on Eleven and Brenner, Vecna also goes after victims who have dealt with traumatizing experiences in the past (reminiscent of his childhood and his time at the Hawkins lab).
Once he takes control of the mind, he traumatizes them by showing the visions of their dark past. He takes them to unknown places and gives them a glimpse of himself. The pain of his victims doesn't end here. Every single one of his victims experiences nose bleeding and severe headaches as well.
If Vecna can overwhelm their victim with fear, and keep them from resisting, their fate is almost certainly sealed. In the real world, he makes the victim levitate while in their trance, before snapping their bones and neck, and crushing their eyes.
“Asperger Syndrome is characterized by significant difficulties in social interaction and nonverbal communication, alongside restricted and repetitive patterns of behavior and interests.”
The fan-favorite character ended the season in a coma with her bones broken and eyes blinded at the hands of Vecna. Max technically died for one whole minute before Eleven revived her friend, but Eleven's powers weren't enough to bring Max fully back to life.
Speaking on the Happy Sad Confused podcast, the brothers confirmed that Max is "braindead and blind and all of her bones are broken".
But new villain Vecna is a reflection of something very real: post-traumatic stress disorder, depression and grief.
In the episodes leading up to his death, Billy was consistently abusive towards Max and her friends. Max says she “wanted him out of her life” and she is undeniably valid in feeling that way because of his actions. The first introduction of Billy showed the brute nature of his character.
Meanwhile, on the Happy Sad Confused podcast, the Duffer brothers added more insult to injury by saying that Max is literally "braindead and blind and all of her bones are broken".
Vecna as a Means for Externalizing Trauma and Depression
Chaiken suggests that while Vecna is a source of horror in Stranger Things, the monster can also serve as a useful vessel for externalizing issues like trauma and depression.
At some point in 1985, Fred was in a car accident which killed another student. He sustained facial injuries himself in this accident, which caused a scar on his left cheek.
Trauma fuels him
Also in episode 8 of Season 4 named “Papa,” Dr. Brenner stated that Vecna consumes everything about his victims.
Vecna's obsession with time appears to be linked to his hatred of humanity. He views time as a human imposition on the natural world; an attempt to impose order on nature.
"Vecna seems to be actually intrigued by Nancy being able to figure him out, to be able to get this close to the truth... I think this is more Vecna's narcissistic traits that pull him to Nancy, why he wants to give her this information."
When One massacres the rest of the children in Hawkins Lab, Eleven banishes him to the Upside Down in the same way she banishes the Demogorgon from season one. One is sent hurtling through the Mind Flayer's lightning and is horribly disfigured, transforming into Vecna.
She breaks free, momentarily incapacitates Vecna, and runs with the determination to live toward her friends, dodging debris that Vecna throws in her path. Max hurls herself through the portal, awakes from the trance, and is held by Lucas (Caleb McLaughlin).
Realizing he had tremendous psychic power, he haunted his family with visions before ultimately killing most of them. His father was framed for the murders and locked away in a mental hospital as a disturbed serial killer. Henry then found himself in the care of Brenner, who decided he wanted more kids like the boy.
Eleven has a memory during this episode and realizes that 001/Henry Creel (Jamie Campbell Bower) wants her to join him on his evil journey, and she banished him to the Upside Down. 001 then transformed into Vecna, the horrifying Stranger Things villain.