Amid the mind-boggling numbers being bandied around as the summer transfer season for footballers reaches a climax, here are a few more sobering sums.

By some estimates as many as three in five former players will be declared bankrupt, often blighted by bad financial advice. At least 150 ex-professionals are currently in prison. Clarke Carlisle, chairman of the Professional Footballers' Association, believes hundreds of current players face mental health issues. More than 700 a year end up being pitched out of the sport in their 20s after failing to win a new contract.

That the life of a professional footballer can be prone to severe and unusual pressures as well as huge fame and fortune, often at the same time, was highlighted on Monday by the latest episode in the life of Paul Gascoigne.

The former Tottenham Hotspur, Lazio and England midfielder was fined £1,000 after he admitted drunkenly assaulting a security guard at Stevenage railway station on 4 July. Gascoigne, who has battled alcoholism for many years, was fined £600 for an assault charge and £400 for a drunk and disorderly charge.

The 46-year-old, who received treatment for alcoholism in a US clinic this year amid much conjecture about his future, was originally charged with two counts of assault, one involving his ex-wife Sheryl. That was dropped.

Monday's fine was made as one of his erstwhile opponents, former Arsenal left-back Kenny Sansom, admitted to sleeping on a park bench over the weekend. It emerged that the 54-year-old, capped 86 times by England and a £1m player in 1980 when that was a huge fee, was homeless and battling alcoholism.

After he gave an interview in which he said he would be "better off dead", the Professional Footballers' Association (PFA) said on Monday that Sansom was now staying in a hotel and its counsellors were discussing treatment options with him.

"We have helped Paul continuously since he's had his problems. We get him back on track but then it can be a pattern," said PFA chief executive Gordon Taylor.

"Coming out of the game and losing that everyday involvement has not been easy for him, the same for Kenny Sansom."

Gascoigne, who with his starring role in Italia 90 helped bring football to a new audience, and Sansom plied their trade in an era when serious money started to flow into the game as it became a key driver of pay TV subscriptions.

But theirs was an era on the cusp, when the influence of overseas players and managers ushered in during the time of the Premier League had yet to disrupt the drinking culture well documented by Tony Adams, Paul Merson and others.

So clear are the memories, from Technicolor Panini stickers to the nostalgia shows that are a staple of Sky Sports, that their reduced circumstances jar even more than those players of the 1960s and 1970s who have fallen on hard times.

Some of the changes since their time on the pitch, such as the increased focus on nutrition, have helped. Others, such as the continued escalation of the gambling culture as wages have spiralled, have not.

The PFA insists it is doing all it can to help current and former players with a range of often linked issues from alcohol and gambling addictions to bankruptcy and mental health issues.

"They range across the spectrum from young men who are 16 or 17 and the people in Paul Gascoigne's time of life who are long since retired," said Carlisle. He added:

"This only seems to come to the fore when there is a Paul Gascoigne or a Kenny Sansom. It's good to highlight their case, but my concern is for the 17-year-old boy at Aldershot or Barnet or Northampton who hasn't go the support network or the celebrity friends. That's where we need to focus."

Taylor said the support provided ranged from funding for the "disaster recovery" of the Sporting Chance Clinic of which Adams has been an enthusiastic supporter, to a network of counsellors and an education programme aimed at ensuring young academy prospects are better prepared for the challenges they face.

"There are systems and support mechanisms in place that we wouldn't have dreamed of even when I started the game in '96, let alone 20 or 30 years ago," added Carlisle, who retired from playing for Northampton Town this summer and recently made the BBC documentary Football's Suicide Secret, about the taboo of mental health issues within the game.

"There is a shift in attitude where players are being viewed as people and not as assets. It's not comprehensive, which is where we need it to be, but attitudes are changing."

The dressing room stigma attached to admitting mistakes – whether money troubles stemming from bad advice over tax schemes or a drink problem – remains a serious issue. Carlisle said the PFA had work to do in reassuring footballers that their cases would remain confidential, even to their clubs, adding that for every player splashed over the papers, "hundreds" were quietly in recovery.

There are pressures peculiar to football – a short, easily curtailed career, potentially earning a large amount of money in a short space of time, a lack of education or good advice and the pressure of performing in public among them. But Carlisle insisted it was not a helpful way to look at the problem.

"These are issues that affect society. This isn't specifically a problem within football. The difference being the lives of footballers are scrutinised," he said.

As the arc of Gascoigne's post-football life shows, it could be argued that it was the routine and camaraderie of a life in the sport that helped disguise lifelong problems, and it was retirement, which has been likened to post-traumatic stress by some, that brought them to the fore.

If the one certainty is that there will be more Gascoignes and more Sansoms, football at least insists it is getting better at helping them.

"It's one of the most disappointing ends when you lay everything before a person but they are still incapable of grasping that help. There are some cases where no matter how much time and effort you put in they are unable to make the decisions conducive to a healthy lifestyle," said Carlisle. Or, as Taylor put it: "Often you are taking them to water but you can't help them drink."