A psychologist treating former ABC presenter Andy Muirhead has told a court he viewed child pornography because of work stress and not for sexual gratification.
Janet Haines has told the Tasmanian Supreme Court there were no indicators Muirhead could be considered a paedophile.
She said the 36-year-old fell into a small group of offenders, recognised by new studies, who viewed child pornography for other reasons.
The former host of the ABC's television show Collectors and its Hobart breakfast radio program has pleaded guilty to three charges of accessing and possessing child exploitation material.
Dr Haines had previously provided a psychologist's report to the court to be considered prior to sentencing.
She was required to give evidence after Commonwealth prosecutor Maitland Lincoln took issue with the report's finding that Muirhead had no sexual interest in children.
Dr Haines said Muirhead had developed a dissociation condition after working up to seven days a week in the two ABC jobs.
"He was exhausted, he didn't have any balance in his life," she told the court on Friday.
"That level of pressure increases people's stress levels, it increases their arousal.
"That level of arousal starts to feel normal."
She said the arousal was not sexual but involved the "sympathetic" nervous system causing symptoms such as increased adrenaline and heart rate.
A sense of detachment followed and heavy use of the internet for legitimate purposes then turned into browsing to find a "welcome diversion".
Dr Haines said Muirhead had initially viewed adult pornography for sexual reasons but soon lost interest in it before "accidentally" coming across child-based material.
"You're drawn to it because it is so alien to your value system," she said.
She said the viewing of about 13,000 images over 16 months, at times on a daily basis, was irrelevant because Muirhead's dissociative condition meant he lost track of those kinds of numbers.
Dr Haines said she would have been ethically obliged to treat Muirhead differently if she had believed he was a paedophile.
Mr Lincoln said the viewing of so many images over a long period, some at the highest level of severity, meant Dr Haines' report should be ignored in determining a sentence.
"If he had a shock, he certainly went on looking at it," he said.
He said 5840 additional non-pornographic images of children since found among Muirhead's files added weight to the argument he had an interest in children.
Chief Justice Ewan Crawford remanded Muirhead in custody for sentencing on October 1.