Pony Psychology Series

As its name implies, Saddlesoap Opera's Pony Psychology series delves into the minds and personal problems of the main cast of My Little Pony Friendship Is Magic, with their own interpretation of their more... unstable moments. In order, the series goes:

Fluttershy: Origins: After the Grand Galloping Gala, Fluttershy reflects upon her actions and how much it reminds her of her childhood.
Pinkie Pie: Schism: Rainbow Dash accidentally catches Pinkie Pie in an unguarded moment, discovering an uncomfortable secret -- and as we all know, spilling a secret is the fastest way to lose a friend FOREVER!
Rainbow Dash: Dependence: Dash turns to Fluttershy for help relaxing, but the cure may be worse than the original problem...
Applejack: Exposure: Applejack takes a lot of pride in being honest, but when that honesty extends to sharing all her feelings, complications quickly ensue.
Rarity: Loss: Rarity may be generous, but all her giving has a hidden cost -- and that's becoming too much to bear.
Twilight Sparkle: Spellbound: As her friends' struggles with their personal problems reaches the breaking point, Twilight learns an Awful Truth from her mentor, one she must come to terms with if she's to have any hope of helping anyone.

In addition, the series has several side stories:

Alicorns: Blame: The truth behind the thousand year-schism between the Princesses comes to light, and is considerably more complex than the old fable of "The Mare in the Moon".
Ditzy Doo: Muffins: What is it with Ponyville's walleyed mailmare? Why does she have a unicorn foal? What does her Cutie Mark mean? And why is she so fixated on muffins? Is she an amnesiac CIA agent or something?
Trixie: Treasure: The once Great and Powerful Trixie comes into possession of the means to get back at the residents of Ponyville - but is she ready to pay the price for that vengeance?

The author has just now started to write a sequel called "Secrets and Lies" set after the end of Season Two. It leads off with a bang when Twilight is forced to kill Topsy Turvy/Screwball in self-defense. Having to hide that from the others leads to problems.

Tropes used in Pony Psychology Series include:

Amnesiac Dissonance: When Ditzy starts to recover her memories, she becomes horribly depressed when she thinks she used to be a mob enforcer and a killer.
Aren't You Going to Ravish Me?: At one point, Rarity assumes that the Mayor's hints about taking a bribe to turn a blind eye to her unpaid taxes mean something entirely different. When she realizes the truth, all her horror and shock at her assumption being proven wrong is directed inward.
- Granted, that was how Big Macintosh got a tax break.
The Atoner: Bright Eyes, who adopted a foal orphaned when she failed to protect her parents from Giovanni's hitpony.
Awful Truth: In Spellbound, the various reveals about the nature of the Elements of Harmony.
Black Magic: Twilight is forced to use Neighcromancy to save Dash's life.
Brainwashed and Crazy: In Treasure, Trixie uses the glamor of Celestia's Regalia to inflict this upon all of Ponyvile, save for Twilight, Snips and Snails.
Cerebus Retcon: The reason Twilight survived all those Amusing Injuries throughout the series? The Element of Magic has made her immortal.
The Conspiracy: According to Fluttershy's mother, the Dragons are always out to get them.
Dark and Troubled Past
Darker and Edgier
Defeat Means Friendship: Once Trixie admitted that she'd acted like a world-class jerk because her feelings were hurt, she apologized to Celestia and went back home to learn a new act.
Empathic Weapon: The Regalia of the Daymare, which is linked to the Elements of Harmony and really dislikes having its powers abused by the wearer for their own selfish ends.
Epiphany Therapy: How Twilight tries to help her friends in the second half of Spellbound.
- How Celestia and her royal guard show Twilight she's a living avatar of magic. "Kill her." (Cue horrified Twilight face and cliffhanger ending.)
Evil Cannot Comprehend Good: In Treasure, Trixie is mystified upon sensing that Fluttershy would have been just as compassionate towards her without the Regalia's glamor forcing her to submit.
The Evils of Free Will: In Treasure, Twilight Sparkle is struck by the thought that Pinkie Pie was finally freed of her depression and made truly happy by losing her free will. It's a sobering thought, and one that makes her submit to being taken back to Trixie.
Eyes of Gold: Ditzy's become a plot point, as Gilda recognizes them.
- They also emerge as a plot point in Secrets and Lies; Twilight's inadvertent admission of her self-defense equicide jolts Ditzy/Bright Eyes into remembering her training as an undercover operative.
Foreshadowing: Each installment foreshadows future events in small ways.
Get a Hold of Yourself, Man!: Twilight telekinetically slaps Rarity in Loss.
Glamour: In Blame, Nightmare Moon's striking appearance and natural intimidation is explained as the effects of a mantle Luna wore, which originally belonged to the princesses' mother. Celestia wears one all the time, and its effects are so powerful even Luna can't fully resist its thrall -- something which causes her no end of frustration.
Fantasy Counterpart Culture: Stalliongrad might be the most prominent example, that with a royal visit from tsarevna in Spellbound (and with perfect Russian to boot). Then there are mentionings of Xiao Ma, San Caballo and Puledria.
Gone Horribly Right: Luna wanted to remove the ponies having to change the seasons and everything themselves; the Everfree Forest, the most feared and hated place in Equestria, is the result.
Hoist By Her Own Petard: In Treasure, Trixie eventually learns that abusing the power of the Regalia caused all her suffering and agony.
Innocent Innuendo: Bright Eyes, when wanting some farrier work done on her hooves, tells Big Mac point-blank "I want you to nail me." Big Mac's first response is a Jaw Drop.
Ironic Echo: A dramatic version in Origins: the last words Fluttershy's mother said to her were an insane scream of "You're going to LOVE ME!"
It Runs in The Family: Fluttershy's deepest fear is that she'll turn out just as insane as her mother. Justified--it's a heriditary disease.
Kissing Under the Influence: Rainbow Dash and Fluttershy.
Love Triangle: Applejack and Fluttershy, for Rainbow Dash.
The Magnificent: Parodied in Treasure, where Trixie is frequently described not just as The Great and Powerful, but in terms suited to her current state, such as The Typical and Commonplace or The Shaky and Anxious.
Malfunction Malady: Trixie's use of the Regalia of the Daymare to punish Ponyville for the end of her career almost killed her.
Mafia Princess: Muffins reveals Gilda the Griffon as one. By the end, she's implied to be taking over her late Uncle's business.
Mama Bear: Ditzy Doo.
Middle Child Syndrome: Trixie had so many siblings that her parents were hard-pressed to care for them all, leaving Trixie feeling neglected and longing to be seen.
My Name Is Not Durwood: It's revealed that "Ditzy Doo" is simply a slurred version of the cover name "Desiderata" that Bright Eyes was using when she infiltrated the Griffon Mafia.
Obfuscating Stupidity: the ending of Muffins clearly implies that Bright Eyes/Ditzy Doo is only feigning being a clumsy scatterbrain again because it's the only way to keep Dinky safe.
Pony Puppets: Trixie inflicts this punishment upon Snips and Snails for humiliating her in the past.
Power At a Price: The Elements of Harmony slowly drive their bearers mad.
Precision F-Strike: Treasure has a variant when Applejack stands up to Trixie -- "My Granny's cookin' is FAN-BUCKIN-TASTIC!"
Rage Against the Reflection: Pinkie's story has her staring into a mirror. Fortunately, Rainbow is able to hear what's going on ...
Revised Ending: Originally, the pegasi ended up as an Official Couple by the end of Spellbound. After readers expressed their concern about the circumstances behind this, however, Saddlesoap Opera went back and tweaked the story so that Dash admits she was under the influence and Fluttershy accepts that, returning to a strong friendship.
Revenge Before Reason: Trixie's need to get payback for "Boast Busters" leads her to steal from Celestia and halfway kill herself using an Empathic Weapon that backfires on her with nearly lethal results.
Revenge by Proxy: Unable to direct her full anger at her sister thanks to her Mantle preventing it, Luna instead gleefully steps up to break the Awful Truth to her perceived replacement Twilight.
Secret Keeper: Rainbow Dash becomes one for Pinkie Pie, and Twilight for Rarity, both against their will.
- Muffins reveals that Rarity knows about Ditzy dyeing her mane blonde, and Ditzy becomes one for The Doctor.
Speech Impediment: Muffins introduces a griffon with a cracked beak, giving him a permanent lisp.
Stepford Smiler: Pinkie Pie.
Tall Poppy Syndrome: According to Loss, Rarity lives in constant fear of this, which is why she's generous to the point of driving herself deep into debt.
Tarot Motifs: Celestia uses one combined with a Themed Tarot Deck to give Twilight greater insight into her friends and explain how to help them.
There Are No Therapists: According to Spellbound, it seems the Magic-bearer's role is to play psychologist and keep the other bearers from going insane.
Written by the Winners: In Alicorns: Blame, it's revealed that Luna wasn't banished for trying to make the night last forever... Instead, it was because she made the Everfree Forest free, with all the beauty and horror of nature unleashed.
Voodoo Shark: The idea that the Elements of Harmony drives the bearers mad only affects Applejack. The rest are explained by outside sources (Fluttershy's problem is hereditary, for instance), and it comes off as something Luna made up to hurt Twilight.
- One could argue otherwise. Rarity, who has the Element of Generosity, became so generous to the point of suffering massive debts, out of a fear of being rejected if she stopped putting others' needs ahead of her own. It's possible that her Element somehow made her think that, or made an already-existing fear into a bigger deal than it actually was. Pinkie, having Laughter, puts on a Stepford Smiler act even when she's not in the mood to laugh at all. Again, it's possible that her Element had something to do with her depression.
- The more you think about Celestia's mantle as a mind-control device, the less sense it makes.