The only surprising thing about the current row engulfing double Olympic champion Mo Farah is that anybody should be surprised.

For the last 25 years, I've interviewed many of the biggest names in British and international athletics and can hardly remember a single occasion when the conversation didn't switch from sport to science and the dread world of the hormone monsters.

These stories tended to unfold in a predictable pattern. First, there would be whispers of suspicion or a failed drugs test, followed by inevitable protestations of innocence. Then, there would be a positive B sample and the excuses rang out. Sometimes, the culprits blamed ginseng tea, a physiological idiosyncrasy or even - in American Olympic star Dennis Mitchell's case - too much sex as the reason for the unnatural levels of testosterone and other illegal substances which had been detected in their system. In several instances, stars such as the late Florence Griffith-Joyner, whose sprint records still stand to this day, blithely responded to any accusations of wrongdoing with the husky-voiced response: "No, no, no, I just put my heart and soul into my races."

There came a point where I just wanted to shout: "Enough! I don't believe a word you're saying and neither do you." I met the aforementioned Mitchell at the Copthorne Hotel in Glasgow in 1993, where he was initially affable as we discussed his bronze medal at the Barcelona Olympics, prior to clamming up when the conversation switched to the question of what to do with drugs offenders. It was the same with Merlene Ottey, a multiple world champion and prolific Games medallist, whose behaviour during our chat - also in Glasgow - saw her move from being the Prom Queen to Carrie in the space of ten minutes. She rubbished the notion that athletics had a systemic problem, only a couple of years after Chinese runners had driven a bus through the record books and then disappeared back whence they came.

Mitchell and Ottey were subsequently exposed as cheats, along with Linford Christie, Marion Jones, Tim Montgomery, Justin Gatlin, and an apparently endless number of Russians. Bans were handed out, medals were stripped from those who had stood on various podia, and the IAAF shed crocodile tears without ever getting to grips with the issue. Almost alone, Liz McColgan, who had as much reason as anybody to bemoan the drugs blight, talked about prison terms for those who defrauded their rivals - and the public - but we are as far away from that scenario happening as ever.

I found myself laughing on Saturday when I read Scotland's Guy Learmonth saying: "Our sport is becoming like cycling in the [Lance] Armstrong era." Where on earth has he been living? Athletics has been linked to the laboratory since the 1970s or even earlier and, if there is a credibility problem, it is entirely of its own making. Successive Olympics have come and gone and, however unfair it may be to the millions of people who use running as a means of keeping fit, charity fundraising or for pure clean fun, the only guarantee is that drugs scandals will keep stinking up the schedules.

As for Farah, he would have been better advised to compete in Sunday's Sainsbury's Grand Prix than pull out on the morning of the event, but in one sense, he was damned if he did and damned if he didn't take part. The knives are out for his coach, Alberto Salazar, who runs the Nike Oregon Project, and has been linked to sustained deployment of banned drugs, and this miserable tale isn't going away. For the moment, there is no suggestion Farah is culpable of anything more than guilt by association, yet one wonders how many of the spectators who travelled to Birmingham will part with their cash so readily the next time he is top of the bill.

That is one of the most frustrating aspects of this sorry saga: the knowledge that while athletics can be one of the most thrilling, visceral pursuits on the planet, it is becoming impossible to watch without drowning in cynicism. Last week, for instance, Gatlin, now 33, ran 9.75secs at the Diamond League meeting in Rome. Does anybody truly believe he achieved that legally? After all, this is a man who has already served not one, but two bans.

So how can the malaise be tackled, if indeed the IAAF intends to do so? One step in the right direction - and yes it would be hugely expensive - would be for the governing body to test every athlete who signs up to their sanctioned events every time they run, jump or throw. Some may retort this is impractical, but if you consider the changes - and accompanying inconvenience - which have been made to airport security since 9/11, it shouldn't be beyond the wit of the authorities to clamp down on those who earn vast riches from sponsors, TV deals and paying customers. Oh, and there should be no third time lucky for Gatlin & Co. One strike and you're out.

I used to love athletics and be fascinated by the exploits of Michael Johnson in his pomp. I still find myself getting goosebumps from beholding the wondrous Usain Bolt. But my passion has dwindled and much of that lies in the plague of negative headlines and positive samples in which track and field has become swamped.

I doubt if I'm alone.