WARNING: DISTRESSING CONTENT

Pauline Hanna might have been caught in “a vicious circle” in the weeks before her death in which her disrupted sleep pattern - confirmed by a series of middle-of-the-night work emails - was increasing the risk for suicidal thoughts.

Dr David Menkes, a Yale University-trained expert in psychological medicine, took jurors through an analysis of Hanna’s suicide risk factors today as he was called to testify for the defence in the Philip Polkinghorne murder trial.

“It’s a whole array of difficult risk factors that are in combination,” the University of Auckland professor said of Hanna, who was found dead in the couple’s home on April 5, 2021. “I can say with confidence she had multiple risk factors at that point.”

Polkinghorne, now 71, is accused in the High Court at Auckland of having fatally strangled his wife of 24 years before staging the scene to look like a suicide by hanging. Prosecutors have alleged he had been using some of the $13,000 worth of methamphetamine found inside their Remuera home when he lashed out at Hanna, possibly getting on her back and choking her as she slept in a separate bedroom.

Although the Crown is not required to establish a motive, much of the circumstantial case has focused on the surgeon’s extravagant spending on sex workers and his alleged “double life” with Sydney escort Madison Ashton, who exchanged intimate WhatsApp messages with him in the days following his wife’s death.

The defence, which has been calling witnesses for just over two weeks now, has insisted that Hanna killed herself just as the scene suggested. She had a long history of depression, an intensely stressful job that some witnesses have said she was struggling with and she was taking what two mental health professionals have now described as a dangerous combination of sleeping pills, weight loss drugs, anti-depressants and alcohol.

Menkes, the final of three witnesses to give evidence today, cited a recent study on disturbed sleep patterns.

“A particular link has been found with suicidal thinking,” he said, explaining that the study found even one night of bad sleep can cause a spike in suicidal thoughts the next day.

Disturbed sleep can be a symptom of depression and anxiety, but it can also aggravate them, contributing to mood instabity - hence the vicious circle, Menkes said.

The academic psychiatrist said he didn’t believe Hanna had a serious depressive illness but he agreed with defence lawyer Ron Mansfield KC that such a diagnosis wasn’t necessary to have suicidal thoughts.

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The two went over 20 years of Hanna’s medical history, including 67 prescriptions for anti-depressant Prozac and 55 prescriptions for an amphetamine-based weight loss drug intended only for short-term use in part due to its addictive qualities.

“They keep people awake and they can produce a degree of mood instability,” he said of the weight loss drug.

He also noted medications in 2013 and 2014 intended to reduce - and then altogether restrict - alcohol intake. One note on her medical file said she reported drinking at least a bottle of wine on most evenings for the past 10 years or so with frequent blackouts. He described it as “fairly convincing evidence for alcohol use disorder with dependence”.

Intimate relationship stresses, work stress and in some cases, the recent death of a relative can be risk factors for suicide as well, he said, describing them as “a combination of risk factors that coincided”.

But one of the most concerning risk factors, he said, was her long-term use of sleep pill Zopiclone - a prescription-only medication that was in her husband’s name - combined with alcohol use. A hair sample taken after death suggested she had been taking the drug repeatedly for at least six months.

“To me, that’s highly significant,” he said, explaining that it interacts strongly with alcohol and can both worsen depression and increase disinhibition - resulting in “a considerable risk of harm”.

Menkes is expected to return to the witness box tomorrow for cross-examination.

His evidence followed two IT experts - one for police and another for the defence - who were at loggerheads for most of the day as lawyers took turns quizzing them on a single narrow issue: Was Hanna using her phone at 4am on the morning she died?

The defence has suggested that she was on the phone at that time and that she went into the messaging app, perhaps contemplating drafting a goodbye note before suicide. No messages were ever sent and no drafts were found on her phone, but phone logs show the phone twice running an “iMessage identity lookup” service at that time.

Police expert Jun Lee said it wasn’t possible she was on the phone because there were no logs indicating the device had been turned on or moved during those hours. He concluded it must have been something that was running in the background while the phone was asleep.

But Sydney-based defence expert Atakan “Artie” Shahho said the opposite was true. An “iMessage identity lookup” will only be triggered if a user is in the app, he insisted. He said there were some “perplexing” peculiarities with the data, suggesting the police efforts to “jailbreak” the phone - gaining access without the passcode - might have resulted in destroyed activity logs.

At the end of the day, the two experts had made no progress towards bridging their differences, leaving jurors to decide whose explanation - if either - to trust.

The trial, before Justice Graham Lang and the jury, continues tomorrow with more defence witnesses.

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Craig Kapitan is an Auckland-based journalist covering courts and justice. He joined the Herald in 2021 and has reported on courts since 2002 in three newsrooms in the US and New Zealand.

The Herald will be covering the case in a daily podcast, Accused: The Polkinghorne Trial. You can follow the podcast at iHeartRadio, Apple Podcasts, Spotify, through The Front Page feed, or wherever you get your podcasts.