I think Haley's losing it.
— PFC M. Veroni
Psychosis refers to a variety of unstable mental conditions characterized by abnormal behavior. These conditions can be caused by internal physiologic illness, external poisons, and psychologically traumatic experiences. There have been several documented incidents of psychosis in the Metroid series, most notably those caused by prolonged Phazon exposure.
Early symptoms of Phazon Corruption, sometimes called Phazon Madness or Phazon Fever, include bouts of aggression, delusional behavior, and dementia. Space Pirate personnel who developed such symptoms on Tallon IV were often used as adversaries in the Elite Pirate program. Phazon Fever continued to be a problem after the Pirates relocated to Aether, where a technician reportedly attempted to claim their Phazon for himself and held his workmates at gunpoint until security arrived.
Initial experiments in the Project Helix program also produced psychosis in test subjects. Before Sclera's discovery of Vertigo Phazon, infusing Phazon into Space Pirate DNA degenerated brain tissue, and the few that survived infancy suffered severe psychotic breakdowns before they reached maturity.
Experiencing traumatic events can result in a variety of anxiety disorders and symptoms. For example, Private First Class G. Haley, a Trooper that served with the GFMC Task Force Herakles on board the G.F.S. Tyr, suffered from psychosis characterized by insomnia, excessive intrapersonal communication, and intense anxiety after repeated confrontations with the Ing. Lack of personnel kept him on the front lines with his fellow marines, but his condition had degenerated by the time of his death to the point where he was incapable of articulating his morbid fears, as evidenced by his personal log.
Post Traumatic Stress Disorder
Samus Aran suffered from PTSD, or Post Traumatic Stress Disorder, following a holocaust she endured during her childhood on her homeworld, K-2L. During an attack by Space Pirates, led by Ridley, Samus saw her parents graphically murdered.
In the Metroid manga, Samus is depicted suffering from a panic attack when she first encounters Ridley, so many years after their initial encounter. She is plagued by shortness of breath and intense, disturbing flashbacks, and as a result is unable to control her Power Suit. Even after she is rescued from Ridley, the attack continues until the Chozo are able to calm her.
Gray Voice was the first to indicate that Samus's distress was caused by PTSD induced by encountering Ridley. Later, another Chozo confirms that it was traumatic memories of the disaster on K-2L welling up to her consciousness that caused her sudden episode, doing extensive damage while previously suppressed.
During the events of Metroid: Other M, Samus again experiences paralyzing emotional duress when faced with a genetic clone of Ridley, whom she had previously destroyed, leaving her unable to control her Power Suit and exposed to attack. It was only thanks to the intervention of her friend Anthony Higgs that Samus was able to regain control of her suit and engage Ridley in combat.
- "An entire shift of Dynamo workers have been transferred following bouts of Phazon madness. Units have reported to Science Team for use in laboratory studies and the new Elite Pirate program. Their dementia will make them adequate training adversaries for the Elite team." —Scan Data (Metroid Prime)
- "Medical Report 07.199.09
Technician 12 relieved after showing symptoms of "Phazon Fever," in where he claimed the Phazon as his own and held us at gunpoint until security arrived." —Scan Data (Metroid Prime 2: Echoes)
- "Initial Project Helix experiments with Space Pirate embryos were disastrous. The Phazon-infusion process degenerated brain tissue even as it augmented muscle mass. None of what we have termed 'Elite Pirates' lived to maturity; the few that survived their infanthood suffered severe psychotic breakdowns as juveniles, killing anything within their zone of perception. Research team Sclera made a recent breakthrough, in which parasite studies with a Phazon strain code-named 'Vertigo' were highly successful. Since then, we have fused Vertigo Phazon with Space Pirate DNA with great success. The latest batch of Elite Pirates have reached maturity successfully and are ready for field testing and training." —Pirate Data "Elite Pirates" (Metroid Prime)
- "I think Haley's losing it. He talks to himself all the time, and he won't sleep. He almost shot me on watch the other night. I think he thought I was one of those things. I talked to the doc about taking him off the line, and he told me we need all the help we can get. That's true, but if he goes berserk and kills a bunch of us, that won't be very helpful." —Trooper Logs "PFC M. Veroni" (Metroid Prime 2: Echoes)
- "I hear. Them. Everywhere. They're coming. Can't sleep. Ever. They'll eat me. Eat." —Trooper Logs "PFC G. Haley" (Metroid Prime 2: Echoes)
- "Her memories probably came back. Int he distant past, she witnessed the worst kind of disaster... She's the last survivor of a holocaust caused by the Space Pirates, and now... She remembers it all." —Metroid (manga), Chozo, Vol 2 Ch 10 Pg(s) 2
- "Repressed fear will grow inside of you, even if you are unaware that it even exists." —Metroid (manga), Chozo, Vol 2 Ch 10 Pg(s) 2