Sullivan says even if you play only once a week you've got a one-in-three chance of developing a gambling problem, so don't do it on a regular basis or it will start taking control of your life.
The machines are programmed to pay out less than you put in so though you might have small wins which keep you hooked, he says make no mistake, over time you will lose all your money.
Another problem gambling expert the Weekend Herald spoke to described pokie machines as parasites that have evolved based on the ones before which made the most money.
They are seductive to our ancient hunter/gatherer human brains which are neurobiologically vulnerable to addiction, says Dr Philip Townshend, a psychologist who is research director for the Problem Gambling Foundation.
Countries all over the world have experts on problem gambling and pokies are generally top of their lists as the most addictive form.
This week SkyCity's CEO Nigel Morrison, claimed that "pokie machines are less harmful to the public than Lotto tickets and claims of social harm are out of proportion to reality".
This was in response to the furore over the Government's negotiations with SkyCity for concessions - including up to 500 extra pokie machines at its Auckland casino - in exchange for a $350 million national convention centre.
However, Canadian expert, Professor Kevin Harrigan from the University of Waterloo, told the Weekend Herald any initiative to increase the number of machines was a major concern.
"More harm is caused by the negative consequences associated with pokies than from any other form of gambling."
Harrigan spoke in Australia in 2010 where a huge debate is also raging over gaming machines. Adelaide has faced an offer from SkyCity, which also owns the casino there, for concessions in return for contributing to the redevelopment of the city's riverbank precinct.
But whereas South Australia Treasurer Jack Snelling told them they were dreaming, on Wednesday our Prime Minister, John Key, said he had made the convention centre offer to SkyCity.
Harrigan has analysed, among other things, what he calls "losses disguised as winnings" on pokie machines.
When a player puts in, for example, $3.75 and wins $2.25 the machine lights up and gives graphic and sound rewards, but actually there is no win, just a $1.50 loss.
His research has found the number of losses disguised as winnings is 180 per hour and that 18 per cent of spins are losses disguised as wins - 68 per cent are just losses.
Dr Sullivan says each spin ranges from 3.5 to 5 seconds and there are regular "near misses". When people see what they think is a near miss they think "I'm getting close".
They are not, because each spin is random, but even when a problem gambler has lost all their money, he says, they will still sit there staring at the machine.
The total concentration involved in watching the spinning and winning and free turns means not only do other problems disappear but so does time.
People will say they thought they were only playing there for an hour but in reality, five hours had gone past.
Sullivan finds it hard to fathom how Key could consider a deal with Sky City when he has a Ministry of Health and a Department of Internal Affairs working in accordance with the Gambling Act of 2003.
He points out that when the Act was passed it was recognised around the world as forward-thinking because instead of looking at gambling as a way to support the economy, it started looking from a harm minimisation point of view, and with more controls.
"And then suddenly we get it reversed around by this promise to go and say 'well the economy of scale says that we should reward you and let's forget about the problems that come out of that'."
Sullivan says the Act specifies we should have no more than the six existing casinos, based on the idea that we have too many casinos for the size of the country, and three of those are world-size.
"To suddenly add another up to 500 machines - which are bigger than three of the six casinos - in itself is like adding at least another sizeable casino, and that makes a farce of the law."
SkyCity has casinos in Auckland, Hamilton, Christchurch and Queenstown, plus two in Australia, in Adelaide and Darwin.
Takings from Auckland alone blitz all the others.
In the latest half-yearly report, for the six months from end of June 2011 to end of December 2011, Auckland revenue was $268.9 million; revenue from Australia was $187 million.
Though the Australian SkyCity casinos are smaller and Australia has a proliferation of gambling establishments including a thriving club scene, New Zealand Problem Gambling Foundation head Graeme Ramsey says Auckland takings probably demonstrate the "great take-off" in gambling in the late 1980s which he says was sparked by the legalisation of pokie machines.
In 1986 New Zealanders lost $221 million through gambling, he says. By 1996 that had grown to $816 million and in 2006 it had more than doubled again to just under $2 billion.
Half of that, Ramsey says, is from pokie machines.
The Australian Productivity Commission estimated in 2010 that 40 per cent of revenue through machines came from people with problems but Ramsey says that is conservative and the foundation believes it is more like 60 per cent.
But even 40 per cent shows SkyCity's business model is dependent on people with problems "and therein lies the issue". The casino is not a happy, bubbly place, he says: "It's a grim, grim, grim, grim, grim place."
A few years ago Otago University's National Addiction Centre put out a paper explaining that addiction was unique to the human species and resulted from ancient genes interacting with modern human environments.
The genes originate from at least the time of the Ordovician period (500 million years ago) when fish evolved with the capacity of habit formation.
Modern human advances - such as tailor-made cigarettes and electronic gaming machines - can provide a compelling stimulus to an integrating structure in the reptilian part of the human brain which initiates automatic responses to seek and consume, the paper said.
If continued regularly these compelling stimuli spark the development of compulsive behaviour in the individual.
Dr Phil Townshend says the neurobiological pathway which gambling excites is the same one that is excited by alcohol and opiates (it's called the opioid pathway).
"And probably the biological basis of this particular pathway is around being a hunting and gathering species.
"You can see how that really fits in with gambling addiction where you're putting a lot of time and persistence into activity, a bit like you might if you were fishing or if you were hunting.
"We're really good at that; that's how we took over the planet and it's a pretty universal pathway because the humans who weren't keen on being a hunting and gathering species aren't with us anymore."
One of the things about the pathway, he says, is that there seems to be a metronomic (mechanically rhythmic) component and this has clearly been found to be in the two-to-10 second timeframe for the human brain.
A pokie machine spinning every three and a half seconds fits firmly within that timeframe, so though people might like to think addiction only happens to the vulnerable members of society, Dr Townshend says the truth is that, with exposure, any one of us can become addicted.
Are you in trouble?
New Zealand psychologist Dr Sean Sullivan devised this test about gambling.
If you answer yes to four or more questions, gambling may be causing you problems.
1 Sometimes I've felt depressed or anxious after a session of gambling.
2 Sometimes I've felt guilty about the way I gamble.
3 When I think about it, gambling has sometimes caused me problems.
4 Sometimes I've found it better not to tell others, especially my family, about the amount of time or money I spend gambling.
5 I often find that when I stop gambling I've run out of money.
6 Often I get the urge to return to gambling to win back losses from a past session.
7 Yes, I have received criticism about my gambling in the past.
8 Yes, I have tried to win money to pay debts.
The 24 hour Gambling Helpline: 0800 654 655
