I don't know for sure since I haven't read it. But in Naruto fanfics, sometimes the author creates new characters or gives more depth to minor characters from the original series. So it's possible that this fanfic has some unique characters that play a role in the story about depression.
Well, without reading it, it's hard to say for sure. However, given the title, it could be centered around a character who is suffering from depression. In Naruto, there are many characters who have had rough pasts. Maybe this fanfic focuses on one of them, like Sasuke who has lost his family, and delves deeper into how that trauma could lead to a state of depression. It might also show how the character's friends or the ninja community around them either helps or fails to help with their situation.
One key theme could be isolation. Naruto, despite his normally outgoing nature in the original series, might be shown isolating himself when struggling with depression. He could be pushing away his friends, like Sasuke and Sakura, thinking he's a burden to them. Another theme could be self - doubt. He might question his worth as a ninja, all his past achievements seeming meaningless in the face of his inner turmoil. Also, the search for purpose can be a theme. Naruto has always had a strong sense of purpose in the original story, but depression could make him feel like he's lost that, and he has to rediscover what really matters to him in life.
In a fanfic, one possible cause could be the loss of his loved ones. If he were to lose Sasuke again, this time perhaps permanently, it could send him into a deep depression. He's always been so focused on bringing Sasuke back, and if that hope is completely dashed, it would be a huge blow.
Another aspect could be in his physical appearance and actions. He may lose his appetite, so he no longer enjoys his favorite ramen as much. He could also seem less energetic during training, often zoning out and being less focused than before. His eyes might lose their usual spark, always looking a bit dull and lifeless.
For some readers, it can be a form of catharsis. If they have experienced depression themselves or know someone who has, seeing Naruto's journey in the fanfic can be a way to process their own emotions. It can also educate readers about how depression can affect even the most seemingly invincible people, like Naruto. It might inspire them to be more supportive of those with mental health problems in their own lives. Additionally, it can open up discussions about mental health in the Naruto fandom, which can be really positive.
In the fanfic, Naruto's struggle with depression would have a profound impact on his relationships. His friendship with Kakashi - sensei might be tested. Kakashi is used to Naruto's determination, but now he has to deal with a Naruto who is withdrawn. He might struggle to find the right way to encourage Naruto. Naruto's relationship with the villagers could also take a hit. They may not understand mental health issues and see his depression as something to be ashamed of. This could lead to Naruto feeling even more isolated from the community he once fought to protect, while his true friends' efforts to bridge the gap could become a central part of the story.
It can create a lot of internal conflict. For example, Sasuke's depression might cause him to make rash decisions that drive the plot. He could isolate himself from Naruto and the rest of the group, which then leads to the others trying to reach out to him. This pursuit can form a major part of the fanfic's plot.
A common theme could be his broken relationships. Depression can make Naruto push away those close to him, like Sasuke or Sakura. The fanfic might show how he withdraws from their company, creating a rift. Another aspect is the theme of masking his pain. Naruto is used to putting on a brave face, but in this scenario, the fanfic could explore how difficult it is for him to keep up that facade when he's actually suffering from depression. And finally, there's the theme of self - destruction. He might engage in behaviors that are harmful to himself as a result of his depressive state.
The author often shows Naruto being withdrawn. He may avoid his friends and spend more time alone. His usual energetic and talkative nature is replaced by silence.