I am not a fan of hardcore porn (sure, they supposedly show "real" sex, but if real sex involved being two inches from Ron Jeremy's fat, hairy bunghole and sweaty, pistoning perineum, I would swear off it for life!). I do really like the pre-hardcore "roughie" films though, not because I'm a potential rapist or sexual sadist, but because they were genuine films with genuine drama made by filmmakers and actors who, while certainly low-budget and low-rent, had a modicum of actual talent. Hardcore films, on the other hand, are usually simply tedious documents of people having sex recorded by whatever visual medium happened to be on hand by people who have no talent whatsoever. There is rarely even the basic suspension of disbelief necessary to feel you are watching a real movie.
The best thing I can say about this film then is that if you took away the hardcore sex, it would be a fairly decent "roughie". And if you took away ALL the sex, you might even be able to pass it off as a 50's nd 60's-sytle "J.D." (juvenile delinquent) film (albeit a very short one). I won't re-hash the plot, but suffice it to say, it does actually HAVE one. It is a somewhat disturbing as other reviewers have said, but I think it would actually be more disturbing if it weren't hardcore porn. The long sex scenes actually interrupt the effectively unsettling atmosphere the film manages to create at times.
According to the generally unreliable IMDb dates, this film was practically released on lead actress Jean Jenning's 18th birthday, so there is some question of whether she was "barely legal" or "barely illegal" when she made it. There is no question that she was involved in "adult" films though years ealier when she was definitely underage and sometimes with her male lead here, Fred Lincoln of "Last House on the Left" fame. (And I find it extremely hypocritical that Lincoln has bad-mouthed "Last House" so much over the years, considering that in that film he only PLAYED a FICTIONAL child molester). Anyway, Jennings looks about 25 here and she was definitely a lot older than I was in 1975, so I'm personally not going to worry about that. She is surprisingly good here as a teenage mental patient, as is Lincoln in a non-sex role as her bent doctor. This is not bad for a hardcore porn film.