Survivor guilt
Survivor guilt was a psychological disorder where a person feels guilty for surviving a traumatic experience or blames themselves for something they did wrong that caused the death of others.

Following the death of Captain Garrovick and most of the crew from the  by a dikironium cloud creature, Kirk felt terrible guilt over his captain's death. Years later, Kirk admitted that "I could have killed that thing if I'd fired soon enough the first time"; however, Doctor Leonard McCoy attempted to dispel Kirk's guilt, which was bordering on obsession, assuring him, "You don't know that, Jim." ()

In 2366, the crew of the  discovered that Kevin Uxbridge was the only survivor of the attack on Rana IV by the Husnock after he perpetrated a deception to try to get them to stop investigating the events of the attack. After he stated that he had destroyed the Husnock in his grief, Doctor Beverly Crusher asked him why he had revealed this to them now, if it was guilt for not helping the colonists to defend against the attack. He, however, explained that she and the others did not understand the scope of his crime, that he had not merely destroyed simply one Husnock warship in his anger, but had in fact committed the genocide of the entire Husnock species. ()

In an alternate timeline, when Chakotay and Harry Kim successfully returned to Earth in 2375, via slipstream aboard the , at the cost of the loss of , Kim experienced the profound effects of survivor guilt, also to the point of obsession. Kim's counselors at Starfleet Headquarters told him "You must learn to accept the fact that you lived. Embrace life, move forward."In 2390, while in discussion with The Doctor, following his reactivation, about the occurrences of the past fifteen, The Doctor pointed out that "I suppose it must have been difficult, with all your friends and colleagues left behind." Kim caught on to what The Doctor was getting at, he recalled the diagnosis, but still did all he could to undo the wrong he did. Upon finally correcting his mistake Kim left a message to his past self explaining, "Fifteen years ago, I made a mistake and one hundred and fifty people died. I've spent every day since then regretting that mistake, but if you're watching this right now, that means all of that has changed. You owe me one." ()

In 3190, Dr. Kovich assessed Dr. Hugh Culber's savior complex at getting a second chance at life as a form of survivor guilt. He described Culber's need to feel a purpose as thinking that if he did not have one that his very existence was a middle finger to anyone who had ever lost anyone, which was everyone. He further told him that it was how he escaped his persistent guilt of being alive and that he needed to find a purpose in something other than work or he would fail those in the chair in front of him. ()

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Psychological conditions