Ytukyg

TOS had one. "The Doomsday Machine" had Commodore Matt Decker lose his crew despite taking the action he believed would save them. He comes away with post traumatic stress (before it even had a name) and guilt as both survivor and inadvertent agent of the death of his entire crew. It all manifests as he bullies his way into temporary command of the Enterprise to attempt a reckless and futile attack on the planet eater. When Spock relieves him of command, he steals a shuttlecraft in which he gives up his own life.

Mental health figures in a few other TOS episodes too:

• "Whom Gods Destroy" - the setting is a "home for the criminally insane". Not really an exploration of mental health issues, just a pretense for Kirk to go mano-a-mano with an unstable genius.


• "Dagger of the Mind" - set on another "home for the criminally insane". Again, not an exploration of mental health issues so much as a pretense for Kirk and his pretty assistant to outwit a mildly evil doctor.


• "Obsession" - When the Enterprise crew encounters a killer cloud entity which Kirk recognizes from his own past, guilt surfaces surrounding his behavior during the original encounter and he gets a little obsessed with the creature's destruction.

DS9 attempts to tackle PTSD in the episode "It's Only A Paper Moon" (season 7, episode 10).

The plot revolves around Nog dealing with the fallout from losing his leg in a previous episode. I'm not at all qualified to comment on how well the episode does at handling PTSD, but, being an episodic show, it's still mostly resolved by the end of the episode.

Edit to add that you could make an argument that in the DS9 episode The Visitor (season 4, episode 3), it shows Jake dealing with the long term effects of grief, though they don't really address it head on.

The same can be said of Janeway in the season 7, episode of Voyager "The Void." That episode shows her coming to grips with her guilt over stranding Voyager in the Delta Quadrant.

Several TNG episodes were centered around various mental health problems, mostly (though not always) of minor characters.

Perhaps most prominently, 4x02 "Family" deals with Captain Picard's lingering trauma from his capture by the Borg over the course of "The Best of Both Worlds". This event and its long-term impact will continue to be referenced throughout the series and into the movie First Contact.

4x12 "The Wounded" centers around Captain Maxwell, a veteran of the war with the Cardassians, who suffers some flavor of PTSD and is convinced as a result that the Cardassians need to be destroyed. (I'd call this paranoia, except that they were indeed up to no good.)

Grief and coping were the subject of several episodes, including 5x11 "Hero Worship", where a child survivor of a wrecked ship tries to emulate Data in order to bury his grief, and 7x07 "Dark Page" that details Lwaxana Trio's (characteristically overwrought) reaction to the long-ago death of her first daughter.

Suicide was the topic of 7x18 "Eye of the Beholder", with the unexpected and initially unexplained death of a junior Enterprise officer. Bonus Lwaxana points: she also had a brush with suicide in 4x22 "Half a Life", although that was socially-expected euthanasia rather than a mental issue per se.

I can recall two episodes about psychotic disorders that try to look deeper into uncontrollable urge for violence.

One is "Meld" from "Voyager" - about a member crew Suder who killed people "for no reason" and Tuvok, being unable to understand this illogical action tries to realize what such psychotic perception really is.

In "Repentance" ("Voyager" again) they transport a convicted murderer who is explained to be a typical psychopath, feeling joy harming others. He is a violent man who did awful things. The Doctor examines him and concludes that he got a neuro-physiological explanation to his mental state. The Doctor then is able to fix his brain physiology to make him able to feel regret and empathy, which he was never able to feel before. After that they face a moral problem - can the "new person" who was cured of his mental illness be judged and punished for what he did previously.

In some ways, the TOS episode Dagger of the Mind dealt with this. Dr. Tristan Adams invents a neural neutralizer that can render a subject susceptible to suggestions. In his experiments to best use the device, he drives one of his own staff mad. He also produces people devoid of any emotions. The device ultimately kills him when it reactivates unexpectedly and empties Adams' mind of everything, since nobody was there to replace what the device was taking away.

The (perhaps shortsightedly written) TOS episode Whom Gods Destroy involves an asylum for the criminally insane, multiple criminally insane characters including Garth of Izar, as well as a revolutionary medicine which was believed to have the ability to wipe out any and all remaining forms of mental illness.

I am not sure if it is correct to say that this episode "deals with mental health" the way the OP asks.

1. The M5's behavior suggests that its implementation of human engrams was faulty, as it did not sufficiently balance the concepts of good and evil with the concept of self preservation.


2. During Daystrom's "breakdown" he describes anger and deep frustration with the treatment his research has received and lack of personal credit, though I am not sure if the in-universe explanation links that frustration with M5's profound invulnerability.

In the TOS episode The Ultimate Computer the famous scientist Dr. Richard Daystrom (namesake of the Daystron Institude) has a mental breakdown after the M5, closely modeled after Daystrom's own mind, had committed what Daystrom felt to be murder by intentionally destroying a Starfleet ship as part of an exercise gone wrong. At the end, Daystrom needed to be taken to "a total rehabilitation facility".

Incredible performance by William Marshall (alternate source)

Daystrom: You are great, I am great.

Twenty years of groping to prove the things I’ve done before are not accidents.

Seminars and lectures to rows of fools who couldn’t begin to understand my systems.

“Colleagues.” Colleagues laughing behind my back at the boy wonder. Becoming famous building on my work. Building on my work!

[...]

Bones: Jim he’s on the edge of a nervous breakdown if not insanity.

Act Three

[...]In the briefing room, the senior staff collaborates on a plan to gain back control by focusing on a certain relay unit between the M-5 and the bridge. McCoy goes to Daystrom to convince him to shut off the M-5. Daystrom, on the other hand, defends the M-5, saying it's learning, and further, that the advance the M-5 represents would liberate man from hazardous duties, saving life. McCoy notes later to Kirk that Daystrom reacts toward the computer as a father would to his child. Even if the child went anti-social and killed a person, a father would protect the child.

Act Four

[...]Now that the M-5 has committed murder, Kirk confronts Daystrom, convincing him that the M-5 is doing more than originally designed. He demands that Daystrom attempt to reason with M-5, as Daystrom admits it is his engrams that he imprinted on the machine. However, he goes mad in the effort, realizing his reputation is at stake. In his delirium, he lashes out at Kirk, but is subdued by a Vulcan nerve pinch from Spock.

McCoy hauls him off to sickbay, and Spock notes the self-preservation that the M-5 is displaying is probably a consequence of Daystrom's engram imprinting.

[...]Dr. Daystrom, meanwhile, is cared for in sickbay under sedation and heavy restraint to await transfer to a total rehabilitation facility, under McCoy's recommendation. Kirk orders that Sulu plot a return course to Starbase 6.

Source: http://memory-alpha.wikia.com/wiki/The_Ultimate_Computer_(episode)

Doctor Richard Daystrom was one of the most influential Human scientists of the 23rd century. Born in 2219, Daystrom was considered a genius in his day, and was compared to Albert Einstein, Kazanga, and Sitar of Vulcan. He was the inventor of the comptronic and duotronic computer systems.

Source: http://memory-alpha.wikia.com/wiki/Richard_Daystrom

I just watched the Star Trek: Voyager episode "Latent Image," which I believe qualifies as an episode about mental health. In it, it is revealed that eighteen months prior to the episode, Captain Janeway had the Doctor's memory wiped. This happened after the Doc was faced with a decision between saving the life of one crewman over another, and ultimately chose Ensign Harry Kim due to them being friends. The Doctor begins to lose his mind in the following days due to his ethical and cognitive subroutines repeating the same thoughts over and over.

In various ways a number of episodes of TOS dealt with mental health/depression/suicide, or a an examination of a character struggling with a long-term mental illness, mental health seems to come up often as a plot point.

"Turnabout Intruder", mentally unstable women switches minds with Kick.

"The Tholian Web"-the crew of the Defiant killed one another because of the effects of interphase.

"The Way to Eden"-Spock attempts to reason with Dr. Sevrin but concludes that Sevrin is not sane.

"The Alternative Factor"-Lazarus, finding out his alternate universe counterpart, "went insane and became obsessed with destroying him."

"Space Seed"-well, Kahn!

"The Return of the Archon"-an entire society in some mass delusion, sort of.

"The Naked Time"-Lt. Joe Tormolen kills himself, the rest of the crew does not do so well either.

"The Cloud Minders", the Troglytes develop diminished mental capacity and heightened violent emotional outbursts.

"Wolf in the Fold"-serial killers, but caused by an alien.

Thanks, this was a fun question to think about.

I'll throw in the obvious TOS Amok Time. Spock goes off the rails and the title of the episode "Amok" is a Malay word for going nuts and berzerkoid.

"The Outcast" in Star Trek:TNG has Riker become romantically involved with Soren, a J'naii. The androgynous J'naii see all expressions of sexuality as mental illness. Soren is discovered and successfully (by J'naii standards) treated.

There are a number of episodes in which characters experience situations that cause them to doubt their own sanity. Although these experiences are eventually revealed to be caused by some outside influence or natural phenomenon, the characters are forced to at least consider the possibility that they are suffering from delusions or some other form of mental illness.

One example from TNG is "Remember Me". Beverly Crusher is trapped in a pocket universe that looks just like the Enterprise, except that crew members keep disappearing, and nobody else remembers that they ever existed:

CRUSHER: Deanna. I need you to tell me if I've gone completely mad.

TROI: If you can ask the question, I'd say no.

CRUSHER: Don't evade the question.

TROI: Then ask me one I can answer.

CRUSHER: Deanna, I've delivered babies that no longer exist. No one else remembers them. Yet I can close my eyes, and see their faces as clearly as I see yours now. What if it's not some huge conspiracy? What if it is just me?

TROI: What if it is just you?

In another TNG episode, "Frame of Mind", Riker is starring in a play on the Enterprise, playing the part of an alleged murderer being treated in an insane asylum. As the episode progresses, Riker finds that he himself is in the asylum, and he is told that his life aboard the Enterprise was merely a delusion:

RIKER: I was on the Enterprise in the middle of a play. But it was here. It was not real, it was on a stage.

SYRUS: I can assure you this is not a stage. Do you remember your name?

RIKER: I'm Commander. Commander. A second ago I knew who I was. I was on the ship. I was in a play. And now I'm having trouble remembering anything.

SYRUS: That's good. You're starting to come out of your delusional state.