BREAKING: Major depression brought on by a difficult transformation back into mainstream life after a 20-year high profile sporting career had ultimately driven former rugby league star Jason Smith into cocaine use, a court has heard.

The former Queensland State of Origin and Australian Test star, who had no previous criminal history, pleaded guilty before Toowoomba Supreme Court to eight counts of possessing cocaine above the schedule of 2g.

The 44-year-old was charged with a co-accused in January last year with trafficking in the drug, but sentencing judge Justice Ann Lyons said there was no evidence Smith had sold any of the drug.

She accepted by the evidence he had been a heavy user of cocaine and was capable of consuming 4g or so of the drug a week.

Crown prosecutor David Jones told the court Smith and his co-accused had been charged through phone calls with an alleged drug dealer who was being targetted by a Crime Corruption Commission operation in 2014.

Though a police search of Smith's residence and hotel had found no drug, the Crown inferred by the phone call material that he and his co-accused had accessed about 112g of cocaine over a seven month period for which they paid more than $40,000.

It was alleged the pair had also sourced some of the drug for other parties, the court heard.

Asked by Justice Lyons if he had anything to say, from the dock Smith told Her Honour: "Not once have I ever dealt drugs".

Due to the inferred amount of drug, Mr Jones said the Crown alleged a certain commerciality was involved.

However, Smith's barrister Alastair McDougall told the court his client had had a "terrible, terrible drug problem" at the time after reaching the depths of depression in 2014.

A psychologists report tended to the court told of Smith having suffered a compulsive disorder all his life but that had been controlled by his high achievement in rugby league from the time he was 18.

However, when the adulation was over and he had to return to a normal life, he had struggled with the transition.

The psychologist also found Smith had suffered chronic traumatic encephalopathy (CTE) a progressive degenerative disease of the brain found in athletes (and others) with a history of repetitive brain trauma from on-field concussion episodes which made him further susceptible to substance abuse.

Smith's IQ was evaluated as being among the top 6% of the population, the psychologist found.

Mr McDougall said since his client's arrest, he had been clean of drugs, attested to by four clean drug reports tended to court, the most recent of which was done this week.

Media reports which had gone international when his client was charged with trafficking was a "slur on his name forever" and his client was most remorseful that his children, their friends and classmates now know he had been a drug addict, he said.

The wide-spread media coverage of his client since the arrest had had a huge toll on his reputation, his family life and his hotel business which in itself was punishment, Mr McDougall submitted.

His client was actively involved in the community through junior and senior rugby league and numerous charities that he supported including offering his hotel free of charge for charity functions.

In his report, the psychologist recommended strongly that Smith would not re-offend, he said.

Justice Lyons said she accepted Smith had been a heavy user of the drug and that he was now medicated for depression and his mental health had improved since he got away from the drug.

However, she said cocaine was a serious drug which caused people serious problems and sentenced Smith to three years' jail but ordered he be released immediately on parole.