When director Darren Aronofsky says Requiem for a Dream “is not a drug movie,” it doesn’t sound like an excuse. Yet considering the inaccurate portrayal of the main pharmacologic effect of heroin displayed in his film, a dilating pupil, perhaps we should consider it one.
Based on the 1978 Hubert Selby Jr. novel, Requiem for a Dream is a film about the biological, psychological, and social consequences of addiction. Released in 2000 to a flurry of MPAA scorn and critical acclaim, it interweaves the stories of four desperate Brooklynites who fall victim to the shackles of substance dependence. Although ultimately the film speaks to addictions of all varieties, including television, vanity, and prescription drugs, the film’s major visual motif relates to heroin.
Each time someone uses heroin we see a montage ending with a singular, striking image: a rapidly dilating pupil. While it could be debated ad nauseam what broader significance this image connotes, it is clear that this image is a central metaphor. An eye hovers unflinchingly above the characters on promotional posters. We see two pupils dilate right after the opening credits and dozens of times thereafter. Instead of seeing the characters use heroin, we only see the so-called physiologic effects of it. The dilating pupil is an icon for the film, and in many ways, heroin use itself.
Unfortunately, the image makes no pharmacologic sense. In fact, if they were indeed using heroin, the effect would be precisely the opposite. Heroin is an opioid, which are synthetic versions of naturally occurring derivatives of opium. When opioids enter the bloodstream, they quickly cross into the central nervous system and induce their wide-ranging effects. In addition to the obvious euphoria and pain relief, opioid intoxication classically causes nausea, clammy skin, and pupil constriction.
There are many mechanisms that lead to pupil constriction or dilation. Tethered by muscles that are under involuntary control, the pupil can change size in response to the amount of light, the proximity of an object, neurological damage, or drugs. When heroin enters the body it is rapidly converted to its active form (i.e. morphine), which binds to μ (mu) opioid receptors in the brain (μ is pretentious Greek shorthand for morphine). By cueing several chemicals including acetylcholine, GABA, and the creatively-named Substance P into action, this cascade of events results in an overall deceleration of cognition and upper-level motor processes. (Those of you who have ever taken an opioid, like Codeine, after a dental procedure may know this feeling well.) In coincidental fashion, the excitation of receptors in a nerve bundle called the ciliary ganglion predictably results in muscle contraction and nearly intractable pupil constriction.
As you might surmise, the converse also applies. When central nervous system stimulants, like cocaine or methamphetamine, enter the body they initiate an analogous but opposite chain of reactions that leads to pupil dilation. Similarly, if someone is experiencing physiologic withdrawal from opioids, their pupils will dilate. However, it is quite clear that when pupils dilate in Requiem for a Dream, the characters are not going through opioid withdrawal, which would be accompanied by a completely different set of physiologic signs.
So where exactly did Aronofsky err? Did he fail to research the effects of heroin? Considering the detailed precision of the rest of the film, that is not likely. Did he purposefully choose to show dilation despite the pharmacologic contradiction? If you exclude the effect of opioids, pupil dilation occurs in several emotional states, including fear, sadness, or general arousal. Studies have shown that pupils dilate in response to positive images such as nudity or food, and negative ones such as a disabled person or a crying baby. As “windows to the soul,” pupil reactions are thought to represent our overall cognitive load or level of arousal. The more we think, or the more excited we are, the bigger our pupils get, and vice versa. It is possible Aronofsky wanted to use the image of pupil dilation to show the level of complexity in his characters’ lives.
Yet as the plot moves forward, the characters seem to think less and less. Obtaining heroin consumes more and more of their life at the expense of other decisions, thoughts, and emotions. Perhaps showing their pupils dilating is an intentional contrast to paradoxically highlight the constricting worldview caused by their addiction. As it stands, the image remains a powerful metaphor.
Still, there is some evidence that suggests he merely inadvertently got caught in a contradiction. In the bonus feature interview “Anatomy of a Scene” on the DVD release of Requiem for a Dream, Aronofsky shows a glimpse of a revealing storyboard sketch. There is an image of a colorless eye next to the text “pupils dilate to pinpoint.” To put it simply, it is impossible for pupils to dilate to pinpoint. Pupils are measured according to their diameter in millimeters and the term “pinpoint” is used to refer to pupils that are severely constricted. Heroin intoxication causes pinpoint pupils, heroin withdrawal causes dilated pupils, and never can the two states occur together. At some point Aronofsky got his information crossed and never sorted it out.
Maybe he never realized his mistake; maybe he couldn’t capture pupil constriction on film; or maybe he liked the “eyes wide shut” metaphor a little too much. We will probably never know, but it does not excuse us from opening our own eyes to the real science behind the scenes.