“DRTY DIANA” is an eight-part series that manages to shine a careful spotlight on the universal issue of depression. With some brilliant acting by lead Cassi Maddox, life’s sad ups and downs are seen as a cross-generational issue with an overlay of present-day social media-fueled troubles that haunt folks in their 20s. To its credit, the series generally (key word being generally) avoids cliched settings by allowing Maddox’s portal of Nyaomi to be fairly untethered and spontaneous. With a number of strengths, “DRTY DIANA” is plagued by some major weaknesses which prevents it from being truly excellent. While Maddox is strong in her central role, much of the supporting cast — especially Ashley Klanac and Alexandria Givens — lack her polish and tend to over-emote whenever possible. The plot thread that involves Nyaomi’s mother, who is in the midst of creating a reality show for Bravo, never is really fleshed out and seems utterly superfluous. If there is a connection that ties our star’s depression to her mother’s odd behavior, it never is clearly presented. And while our star’s friends-with-benefits relationship with a college student four years her junior is fitting and relatable, it too sort of just hangs there without much context or connection to Nyaomi’s unstable behavior. Most of all, eight episodes are about two too many to make this a gem. Not all episodes, such as the one called “New Song,” have a subplot that ties together the enigma of mid-20s mental illness. Episode one solidly sets up the story without blurting out every detail. We learn that Nyaomi recently left a job as an ad sales rep after having a more satisfying career as an intern for Rolling Stone magazine and playing in a hard rock band. In the course of subsequent episodes, Nyaomi’s life unravels as her relationships go south and her ability to grasp reality begins to fade. It will take you to the last episode to understand how the title “DRTY DIANA” relates, although if you pay attention closely in the episode “Jackson” and know a bit of the history of Michael Jackson’s 1987 song of the same name, the ending will not come as a surprise. And speaking of the ending — and the ending may be the best part of the series — the climax will leave viewers talking and attaching throw own interpretation to the final minutes. The series is a collaboration between Maddox, a stage actress and Atlanta-based creator Yonas Michael (previously a staff writer on Issa Rae’s “Michelle Obama Diaries”). For both talents, this could be the start of some notable work that will shine on any screen.