Once upon a time I wrote in the morning, jogged in the late afternoon and spent most of my evenings reading. Once upon a time I wrote off as unproductive those days in which I had managed to put down "only" a thousand words. Once upon a time I played video games almost exclusively with friends. Once upon a time I did occasionally binge on games, but these binges rarely had less than a fortnight between them. Once upon a time I was, more or less, content.

"Once upon a time" refers to relatively recent years (2001-2006), during which I wrote several books and published more than 50 pieces of magazine journalism and criticism – a total output of, give or take, 4,500 manuscript pages. I rarely felt very disciplined during this half decade, though I realise this admission invites accusations of disingenuousness. Obviously I was disciplined. These days I have read from start to finish exactly two works of fiction – excepting those I was also reviewing – in the last year. These days I play video games in the morning, play video games in the afternoon and spend my evenings playing video games. These days I still manage to write, but the times I am able to do so for more than three sustained hours have the temporal periodicity of comets with near-earth trajectories.

For a while I hoped that my inability to concentrate on writing and reading was the result of a charred and overworked thalamus. I knew the pace I was on was not sustainable and figured my discipline was treating itself to a rumspringa. I waited patiently for it to stroll back on to the farm, apologetic but invigorated. When this did not happen, I wondered if my intensified attraction to games and my desensitised attraction to literature were reasonable responses to how formally compelling games had quite suddenly become. Three years into my predicament, my discipline remains awol. Games, meanwhile, are even more formally compelling.

It has not helped that during the past three years I have, for what seemed like compelling reasons at the time, frequently upended my life, moving from New York City to Rome to Las Vegas to Tallinn, Estonia, and back, finally, to the United States. With every move I resolved to leave behind my video game consoles, counting on new surroundings, unfamiliar people and different cultures to enable a rediscovery of the joy I once took in my work. Shortly after arriving in Rome, Las Vegas and Tallinn, however, the lines of gameless resolve I had chalked across my mind were wiped clean. In Rome this took two months; in Vegas two weeks; in Tallinn two days. Thus I enjoy the spendthrift distinction of having purchased four Xbox 360 consoles in three years, having abandoned the first to the care of a friend in Brooklyn, left another floating around Europe with parties unknown, and stranded another with a pal in Tallinn (to the irritation of his girlfriend). The last Xbox 360 I bought has plenty of companions: a GameCube, a PlayStation 2 and a PlayStation 3.

Writing and reading allow one consciousness to find and take shelter in another. When the minds of the reader and writer perfectly and inimitably connect, objects, events and emotions become doubly vivid – more real, somehow, than real things. I have spent most of my life seeking out these connections and attempting to create my own. Today, however, the pleasures of literary connection seem leftover and familiar. Today the most consistently pleasurable pursuit in my life is playing video games. Unfortunately, the least useful and financially solvent pursuit in my life is also playing video games. For instance, I woke up this morning at 8am fully intending to write this article. Instead, I played Left 4 Dead until 5pm. The rest of the day went up in a blaze of intermittent catnaps. It is now 10pm and I have only just started to work. I know how I will spend the late, frayed moments before I go to sleep tonight, because they are how I spent last night and the night before that: walking the perimeter of my empty bed and carpet-bombing the equally empty bedroom with promises that tomorrow will not be squandered. I will fall asleep in a futureless, strangely peaceful panic, not really knowing what I will do the next morning and having no firm memory of who, or what, I once was.

The first video game I can recall having to force myself to stop playing was Rockstar's Grand Theft Auto: Vice City, which was released in 2002. I managed to miss Vice City's storied predecessor, Grand Theft Auto III, so I had only oblique notions of what I was getting into. A friend had lobbied me to buy Vice City, so I knew its basic premise: you are a cold-blooded jailbird looking to ascend the bloody social ladder of the fictional Vice City's criminal under- and overworld. (I also knew that Vice City's violent subject matter was said to have inspired crime sprees by a few of the game's least stable fans. Other such sprees would horribly follow. Eight years later, Rockstar has spent more time in court than a playground-abutting pesticide manufactory.) I might have taken better note of the fact that my friend, when speaking of Vice City, admitted he had not slept more than four hours a night since purchasing it and had the ocular spasms and fuse-blown motor reflexes to prove it. Just what, I wanted to know, was so specifically compelling about Vice City? "Just get it and play it," he answered. "You can do anything you want in the game. Anything."

My friend's promise proved to be an exaggeration, but not by very much. You control a young man named Tommy, who has been recently released from prison. He arrives in Vice City – an oceanside metropolis obviously modelled on the Miami of 1986 or so – only to be double-crossed during a coke deal. A few minutes into the game, you watch a cut scene in which Tommy and his lawyer (an anti-Semitic parody of an anti-Semitic parody) decide that revenge must be taken and the coke recovered. Once the cut scene ends, you step outside your lawyer's office. A car is waiting for you. You climb in and begin your drive to the mission destination (a clothing store) clearly marked on your map. The first thing you notice is that your car's radio can be tuned to a number of different radio stations. What is playing on these stations is not a loop of upbeat midi video-game songs or some bombastic score written for the game, but Michael Jackson, Hall and Oates, Cutting Crew and Luther Vandross. While you are wondering at this, you hop a curb, run over some pedestrians and slam into a parked car, all of which a nearby police officer sees. He promptly gives chase. And for the first time you are off, speeding through Vice City's various neighbourhoods. You are still getting accustomed to the driving controls and come into frequent contact with jaywalkers, oncoming traffic, street lights, fire hydrants. Soon your pummelled car (you shed your driver's door two blocks ago) is smoking.

The police, meanwhile, are still in pursuit. You dump the dying car and start to run. How do you get another car? As it happens, a sleek little sporty number called the Stinger is idling beneath a stop light right in front of you. This game is called Grand Theft Auto, is it not? You approach the car, hit the assigned button, and watch Tommy rip the owner from the vehicle, throw him on to the street and drive off. Wait – look there! A motorcycle. Can you drive motorcycles, too? After another brutal vehicular jacking, you fly off an angled ramp in cinematic slow motion while ELO's "Four Little Diamonds" strains the limits of your television's pound-coin-sized speakers.

You have now lost the cops and swing around to head back to your mission, the purpose of which you have forgotten. It gradually dawns on you that this mission is waiting for you to reach it. You do not have to go if you do not want to. Feeling liberated, you drive around Vice City as day gives way to night. When you finally hop off the bike, the citizens of Vice City mumble and yell insults. You approach a man in a construction worker's outfit. He stops, looks at you and waits. The game does not give you any way to interact with this man other than through physical violence, so you take a swing. The fight ends with you stomping the last remaining vitality from the hapless construction worker's blood-squirting body.

When you finally decide to return to the mission point, the rhythm of the game is established. Exploration, mission, cut scene, driving, mayhem, success, exploration, mission, cut scene, driving, mayhem, success. Never has a game felt so open. Never has a game felt so generationally relevant. Never has a game felt so awesomely gratuitous. Never has a game felt so narcotic. When you stopped playing Vice City, its leash-snapped world somehow seemed to go on without you.

Vice City's sequel, Grand Theft Auto: San Andreas, was several magnitudes larger – so large, in fact, I never finished the game. San Andreas gave gamers not one city to explore but three, all of them set in the hip-hop demimonde of California in the early 1990s (though one of the cities is a Vegas clone). It also added dozens of diversions, the most needless of which was the ability of your controlled character, a young man named CJ, to get fat from eating health-restoring pizza and burgers – fat that could be burned off only by hauling CJ's porky ass down to the gym to ride a stationary bike and lift weights. This resulted in a lot of soul-scouring questions as to why a) it even mattered to me that CJ was fat and why b) CJ was getting more physical exercise than I was. Because I could not answer either question satisfactorily, I stopped playing.

Grand Theft Auto IV was announced in May 2006, six months after the launch of the Xbox 360 and six months before the launch of the PlayStation 3, the "next-generation" platforms that have since pushed gaming into the cultural mainstream. When the first next-gen titles began to appear, it was clear that the previous Grand Theft Auto titles – much like Hideo Kojima's similarly brilliant and similarly frustrated Metal Gear Solid titles – were games of next-gen vision and ambition without next-gen hardware to support them. The early word was that GTA IV would scale back the excesses of San Andreas and provide a rounder, more succinctly inhabited game experience. I was living in Las Vegas when GTA IV (after a heartbreaking six-month delay) was finally released.

In Vegas I had made a friend who shared my sacramental devotion to marijuana, my dilated obsession with gaming and my ballistic impatience to play GTA IV. When I was walking home from my neighbourhood game store with my reserved copy of GTA IV in hand, I called my friend to tell him. He let me know that, to celebrate the occasion, he was bringing over some "extra sweetener". My friend's taste in recreational drug abuse vastly exceeded my own, and this extra sweetener turned out to be an alarming quantity of cocaine, a substance with which I had one prior and unexpectedly amiable experience, though I had not seen a frangible white nugget of the stuff since.

While the GTA IV load screen appeared on my television screen, my friend chopped up a dozen lines, reminded me of basic snorting protocol and handed me the straw. I hesitated before taking the tiny hollow sceptre, but not for too long. Know this: I was not someone whose life had been marked by the meticulous collection of bad habits. I chewed tobacco, regularly drank about 10 Diet Cokes a day, and liked marijuana. Beyond that, my greatest vice was probably reading poetry for pleasure. The coke sailed up my nasal passage, leaving behind the delicious smell of a hot leather car seat on the way back from the beach. My previous coke experience had made feeling good an emergency, but this was something else, softer and almost relaxing. This coke, my friend told me, had not been "stepped on" with any amphetamine, and I pretended to know what that meant. I felt as intensely focused as a diamond-cutting laser; Grand Theft Auto IV was ready to go. My friend and I played it for the next 30 hours straight.

Many children who want to believe their tastes are adult will bravely try coffee, find it to be undeniably awful, but recognise something that could one day, conceivably, be enjoyed. Once our tastes as adults are fully developed, it is easy to forget the effort that went into them. Adult taste can be demanding work – so hard, in fact, that some of us, when we become adults, selectively take up a few childish things, as though in defeated acknowledgment that adult taste, with its many bewilderments, is frequently more trouble than it is worth. Few games have more to tell us about this adult retreat into childishness than the Grand Theft Auto series.

In GTA IV you are Niko Bellic, a young immigrant with an ambiguous past. We know he is probably a Serb. We know he fought in the Balkans war. We know he was party to a war-crime atrocity and victim of a double-cross that led to the slaughter of all but three members of his paramilitary unit. We know he has taken life outside of war and it is strongly suggested that he once dabbled in human trafficking. "I did some dumb things and got involved with some idiots," Niko says, early in the game, to his friend Hassan. "We all do dumb things," Hassan replies. "That's what makes us human." The camera closes on Niko as he thinks about this, and for a moment his face becomes as quietly expressive as that of a living actor. "Could be," he says.

Niko has come to Liberty City (the GTA world's run at New York City) at the invitation of his prevaricating cousin, Roman. He wants to start over, leave behind the death and madness of his troubled past, and bathe in the comfort and safety of America. Niko's plan does not go well. Soon enough he is working as a thief and killer. Just as Lolita, as Nabokov piquantly notes in his afterword, was variously read as "old Europe debauching young America" or "young America debauching old Europe", GTA IV leaves itself interpretatively open as to whether Niko is corrupted by America or whether he and his ilk (many of the most vicious characters whose paths Niko crosses are immigrants) are themselves bacterial agents of corruption. The earlier GTA games were less thematically ambitious. Tommy from Vice City is a cackling psychopath, and CJ from San Andreas merely rides the acquisitionist philosophy of hip-hop culture to terminal amorality. They are not characters you root for or even want, in moral terms, to succeed. You want them to succeed only in gameplay terms. The better they do, the more of the gameworld you see.

The stories in Vice City and San Andreas are pastiches of tired filmic genres: crime capers, ghetto dramas, police procedurals. The driving force of both games is the gamer's curiosity: What happens next? What is over here? What if I do this? They are, in this way, childlike and often very silly games, especially San Andreas, which lets you cover your body with ridiculous tattoos and even fly a jetpack. While the gameworlds and subject matter are adult – and under no circumstances should children be allowed near either game – the joy of the gameplay is allowing the vestiges of a repressed, tantrum-throwing, childlike self to run amok. Most games are about attacking a childlike world with an adult mind. The GTA games are the opposite, and one of the most maliciously entertaining mini-games in Vice City and San Andreas is a mayhem mode in which the only goal is to fuck up as much of the gameworld as possible in an allotted period of time.

Niko's real pathos derives not from the gimcrack story but how he looks and moves. Vice City and San Andreas were graphically astounding by the standards of their time, but their character models were woeful – even by the standards of their time. Niko, though, is just about perfect. Dressed in striped black track pants and a dirty windbreaker, Niko looked like the kind of guy one might see staring longingly at the entrance of a strip club in Zagreb, too poor to get in and too self-conscious to try to. When, early in the game, a foul-mouthed minor Russian mafioso named Vlad dismisses Niko as a "yokel", he is not wrong. Niko is a yokel, pathetically so. One of the first things you have to do as Niko is buy new clothes in a Broker (read: Brooklyn) neighbourhood called Hove Beach (read: Sheepshead Bay). The clothing store in question is Russian-owned, its wares fascinatingly ugly. And yet you know, somehow, that Niko, with his slightly less awful new clothes, feels as though he is moving up in the world. The fact that he is, only makes him more heartrending. The times I identified most with Niko were not during the game's frequent cut scenes, which drop bombs of "meaning" and "narrative importance" with nuclear delicacy, but rather when I watched him move through the world of Liberty City and projected on to him my own guesses as to what he was thinking and feeling.

What many without direct experience of the games do know is that they allow you to kill police officers. This is true. GTA games also allow you to kill everyone else. It is sometimes assumed that you somehow get points for killing police officers. Of course you do not get "points" for anything in GTA IV. You get money for completing missions, a number of which are, yes, monstrously violent. While the passersby and pedestrians you slay out of mission will occasionally drop money, it would be hard to argue that the game rewards you for indiscriminate slaughter. People never drop that much money, for one, and the best way to attract the attention of the police and begin a hair-raising transborough chase is to hurt an innocent person. As for the infamous cultural trope that in GTA you can hire a prostitute, pay her, kill her and take her money, this is also true. But you do not have to do this. The game certainly does not ask you to do this. Indeed, after being serviced by a prostitute, Niko will often say something like: "Strange. All that effort to feel this empty." Outside of the inarguably violent missions, it is not what GTA IV asks you to do that is so morally alarming. It is what it allows you to do.

There is no question, though, that GTA IV's violence can be extremely disturbing because it feels unprecedentedly distinct from how, say, films deal with violence. Think of the scene in GoodFellas in which Henry, Tommy, and Jimmy kick to death Billy Batts in Henry's restaurant. Afterwards they decide to put Batts's body in the trunk of Henry's car and bury it in the forest. Of course Batts is not yet dead and spends much of the ride to his place of interment weakly banging the trunk's interior. When Batts is discovered to be alive he is repeatedly, nightmarishly stabbed. The viewer of GoodFellas is implicated in the fate of Billy Batts in any number of ways. Most of us presumably feel closest to Henry, who has the least to do with the crime, but is absolutely an accomplice to it. Henry's point of view is our implied point of view. Thus we/Henry, unlike Tommy and Jimmy, retain our capacity for horror.

In GTA IV, Niko is charged with disposing of the bodies of two men whose deaths Niko is partially responsible for. You/Niko drive across Liberty City with these bodies in the trunk to a corrupt physician who plans to sell the organs on the black market. Here the horror of the situation is refracted in an entirely different manner, which allows the understanding that GTA IV is an engine of a far more intimate process of implication. While on his foul errand, Niko must cope with lifelike traffic, police harassment, red lights, pedestrians, and a poorly handling loan car. Literally thousands of in-game variables complicate what you are trying to do. The GoodFellas scene is an observed experience bound up in one's own moral perception. The GTA IV mission is a procedural event in which one's moral perception of the (admittedly much sillier) situation is scrambled by myriad other distractions. It turns narrative into an active experience, which film is simply unable to do in the same way. And it is moments like this that remind me why I love video games and what they give me that nothing else can.

"Cocaine," Robert Sabbag tells us in the smuggling classic Snowblind, "has no edge. It is strictly a motor drug. It does not alter your perception; it will not even wire you up like the amphetamines. No pictures, no time/space warping, no danger, no fun, no edge. Any individual serious about his chemicals – a heavy hitter – would sooner take 30 No-Doz [caffeine tablets]. Coke is to acid what jazz is to rock. You have to appreciate it. It does not come to you."

Cocaine has its reputation as aggression unleaded largely because many who are attracted to it are themselves aggressive personalities, the reasons for which are as cultural as they are financial. What cocaine does is italicise personality traits, not script new ones. In my case, cocaine did not heighten my aggression in the least. What it did, at least at first, was exaggerate my natural curiosity and need for emotional affection. While on cocaine I became as harmlessly ravenous as Cookie Monster.

This stage, lamentably and predictably, did not last long. A large portion of my last two months in Las Vegas was spent doing cocaine and playing video games – usually Grand Theft Auto IV. When I left Vegas, I thought I was leaving behind not only video games but cocaine. During the last walk I took through the city, in May 2008, I imagined the day's heat as the whoosh of a bullet that, through some oversight of fate, I had managed to dodge. (I was on cocaine at the time.) Even though one of the first things I did when I arrived in Tallinn was buy yet another Xbox 360, I had every intention to obey one of my few prime directives: rigorous adherence to all foreign drug laws. I had been in Tallinn for five months when, in a club, I found myself chatting with someone who was obviously lit. When I gently indicated my awareness of this person's altered state, the result was a magnanimous offer to share. Within no time at all I was back in my apartment, high on cocaine and firing up my Xbox 360. By the week's end, I had a new friend, a new telephone number and a reignited habit. I played through Grand Theft Auto IV again and again after that. The game was faster and more beautiful while I was on cocaine, and breaking laws seemed even more seductive. Niko and I were outlaws, alone as all outlaws are alone, but deludedly content with our freedom and our power.

Soon I was sleeping in my clothes. Soon my hair was stiff and fragrantly unclean. Soon I was doing lines before my Estonian class, staying up for days, curating prodigious nose bleeds and spontaneously vomiting from exhaustion. Soon my pillowcases bore rusty coins of nasal drippage. Soon the only thing I could smell was something like the inside of an empty bottle of prescription medicine. Soon my biweekly phone call to my cocaine dealer was a weekly phone call. Soon I was walking into the night, handing hundreds of dollars in cash to a Russian man whose name I did not even know, waiting in alleys for him to come back – which he always did, though I never fully expected him to – and retreating home, to my Xbox, to GTA IV, to the electrifying solitude of my mind at play in an anarchic digital world. Soon I began to wonder why the only thing I seemed to like to do while on cocaine was play video games. And soon I realised what video games have in common with cocaine: video games, you see, have no edge. You have to appreciate them. They do not come to you.

There are times when I think GTA IV is the most colossal creative achievement of the last 25 years, times when I think of it as an unsurpassable example of what games can do, and times when I think of it as misguided and a failure. No matter what I think about GTA IV, or however I am currently regarding it, my throat gets a little drier, my head a little heavier, and I know I am also thinking about cocaine.

Video games and cocaine feed on my impulsiveness, reinforce my love of solitude and make me feel good and bad in equal measure. The crucial difference is that I believe in what video games want to give me, while the bequest of cocaine is one I loathe. I do know that video games have enriched my life. Of that I have no doubt. They have also done damage to my life. Of that I have no doubt. I let this happen, of course; I even helped the process along. As for cocaine, it has been a long time since I last did it, but not as long as I would like.

What have games given me? Experiences. Not surrogate experiences, but actual experiences, many of which are as important to me as any real memories. Once I wanted games to show me things I could not see in any other medium. Then I wanted games to tell me a story in a way no other medium can. Then I wanted games to redeem something absent in myself. Then I wanted a game experience that pointed not toward but at something. Playing GTA IV on coke for weeks and then months at a time, I learned that maybe all a game can do is point at the person who is playing it, and maybe this has to be enough.

I still have an occasional thought about Niko. When I last left him he was trying to find all the super jump cheats hidden around Liberty City, which is a strange thing for a wanted fugitive to be doing. I know he is still there, in his dingy South Bohan apartment, waiting for me to rejoin him. In early 2009, Rockstar released some new downloadable content for GTA IV, The Lost and Damned, in which you follow the narrative path of Johnny Klebitz, an incidental character in Niko's story (his most memorable line: "Nothing like selling a little dope to let you know you're alive!"), but whose story, it turns out, intersects with Niko's in interesting ways. I played this new GTA IV story for a few hours but gradually lost interest and finally gave up. I realised, dismayingly, that a lot of what powered me through GTA IV had been the cocaine, though it is still my favourite game and probably always will be. I was no longer the person I had been when I loved GTA IV the most, and without Niko Liberty City was not the same.

Niko was not my friend, but I felt for him, deeply. He was clearly having a hard go of it and did not always understand why. He was in a new place that did not make a lot of sense. He was trying, he was doing his best, but he was falling into habits and ways of being that did not reflect his best self. By the end of his long journey, Niko and I had been through a lot together.

• Tom Bissell is the author of five books, including God Lives in St. Petersburg (Faber). His most recent, Extra Lives, will be published in the US in June.