The plight of American soldiers suffering from PTSD as they return from combat in the Middle East is a serious issue, one that frankly deserves more sensitive treatment than that afforded it by writer Adam Simon and director Dito Montiel in “Man Down.” Attempting to be both a truthful psychological study and a tense family-oriented thriller, it succeeds as neither.

The film does demonstrate, however, that despite his string of off-screen problems, Shia LaBeouf remains an actor of commitment and depth. He plays Gabe Drummer, a family man with loving wife Natalie (Kate Mara) and adorable son Johnny (Charlie Shotwell) who, along with Devin (Jai Courtnry), the pal who was virtually his adoptive brother, joins the Marines in the aftermath of 9/11. After typically grueling training under taskmaster Drill Sergeant Miller (Tory Kittles) at Camp Lejeune, the two are sent off to Afghanistan, though Devin is left behind at home for a time because of an injured arm. They wind up in a firefight against Taliban forces in a small town, an encounter that ends tragically and sends Gabe to a session with staff psychologist Peyton (Gary Oldman), who encourages him to come to terms with what happened.

Gabe’s return home is portrayed in an unsettling light. America has become a dystopian place of bombed-out buildings and empty streets. Accompanied by Devin, he searches desperately for his son, and after an encounter with a mumbling derelict (Clifton Collins, Jr.), discovers that the boy is being held captive in what is apparently some sort of juvenile prison facility. He thereupon undertakes an assault on the place to free him.

The approach that Simon and Montiel, along with cinematographer Shelly Johnson and editors Jake Pushinsky and Mark Yoshikawa, bring to this story is one that can be described, in a phrase used by Gabe in one of his talks with his son, as “artsy-fartsy.” The various plot strands—the initial family scenes, the basic training episodes, the battlefield sequences, the therapy session, and the apocalyptic search-and-rescue operation back home—are chopped up into little bits and then shuffled together, until at the end a bit of soap opera clutter is added to the mix and an abrupt twist is introduced to snap the end-of-civilization mood back into something approaching realism.

All of which raises a number of troubling issues. Presumably one purpose at work here is to criticize American policy for failing to provide necessary psychological help to soldiers returning from combat suffering from trauma—after all, a single hour of therapy with Oldman’s counselor is all that we’re told Gabe receives. (A series of caption cards at the close certainly indicates that’s a major concern of the picture.) But what the picture winds up suggesting about the state of many veterans is unsettling, if not somewhat insulting. Secondly, to put it mildly, the film relies to an incredible extent on child endangerment for dramatic effect. Poor little Johnny suffers a virtual orgy of pain and tears before it’s over. That’s an easy device to elicit a visceral emotional reaction from viewers, but a rather meretricious one.

Through it all, however, LaBeouf demonstrates an intensity that’s quite remarkable, giving the often pulpy material far more than it merits. He may be a troubled young man, but he’s grown into an impressive screen presence, leaving behind his juvenile roles while retaining a bit of boyish vulnerability even as his face grows more weathered. The rest of the cast, on the other hand, seem simply to go through the motions without adding much texture or nuance to their roles. The film’s physical production is okay, especially given what appears to be quite a limited budget, but the boot camp and Afghan battle sequences lack scope, though the latter do mange to generate a genuine sense of the horror of close combat that was lacking, for example, in Ang Lee’s recent film, “Billy Lynn’s Long Halftime Walk.”

While there are elements of “Man Down” that sporadically impress, however, overall its mixture of pretentiousness and cheap melodrama, delivered in Johnson’s grimly desaturated widescreen images, proves both tedious and unconvincing. It ends up doing a disservice to the very issues it wants to address.