Only after she had released her new album did the significance of the title became truly clear to Aimee Mann. Mental Illness had been intended as a tongue-in-cheek commentary on the perception that her songs are populated by the dejected and the deranged. But the LP’s arrival coincided with the inauguration of Donald Trump and it occurred to Mann that the record could be interpreted as speaking to the travails afflicting America – a nation in the throes of an emotional meltdown.

“I connected those dots in an overt way,” nods the cult songwriter, speaking from her home in Los Angeles. “There is mental illness in the White House. It’s mostly what people talk about over here. Everybody has had to become more versed in politics. It feels like a matter of life and death – which I suppose it is. He’s crazy and volatile enough to make a very bad impulse decision.”

Mann has gone where few creative types would dare by trying to get inside Trump’s mind. She undertook this unnerving feat with the ballad ‘Can’t You Tell’, recorded for an anti-Trump project curated by novelist Dave Eggers.

“Isn’t anybody going to stop me?” she sings. “I don’t want this job/I don’t want this job, my god /Can’t you tell/I’m unwell”.

“His maturity level is that of a child,” Mann elaborates. “I do think there is something really wrong with him. My armchair diagnosis would be that he is in the first stages of some kind of dementia, which makes you paranoid and irrational. I think he is wildly narcissistic and incredibly immature….He looks at the job the way a child might. ‘I’ll get to eat extra ice-cream and tell everybody what to do.’ That is a profoundly simplistic view.”

Mann grew up near Richmond Virginia, the old capital of the Confederacy. Many of her neighbours would have been Trump voters, so she has perhaps a better perspective on the forces that swept him to power than her music industry peers.

“He is like a cult leader – there is something about him that makes people throw their lot in with Trump. People listen to what he says and they can’t possibly know the details. They are basing their decision as to who to vote for on emotional factors. It just ropes people in.” The present debate over Confederacy monuments chimes a bell with Mann. She recalls a street in Richmond called Monument Avenue. The leafy mall is lined with statues of Civil War heroes from the South.

“I didn’t really pay attention to it growing up. Once it is pointed out that it’s a monument to treason and to slavery… well, then you take those statues down. It’s one thing to not pay attention to something. It’s another to have it pointed out to you and for you to then object to doing anything.”

Mann’s 30-year career charts the many upheavals that have wracked the record industry. She was just 23 when her band ’Til Tuesday were plucked from obscurity by a major label and had a huge hit with ‘Voices Carry’. Life on a major label conveyor belt was not creatively satisfying, however, and in the ’90s she reinvented herself as a solo artist – finding unlikely success when half-sketched demos inspired her friend Paul Thomas Anderson to write the movie Magnolia.

“Magnolia came out of Aimee Mann’s songs, which I was listening to at the time I was starting to write,” he explained. “I had her two solo albums and a lot of her demos, because she’s a friend, and I think the tone she gets is really beautiful. So I thought about using them as a basis, or as inspiration for the film.”

She is looking forward to her October 28 return to Ireland, to which she is a frequent visitor. Mann trusts her trip will be less draining than her last occasion here, when she arrived in the middle of winter stricken with jetlag. The awful weather and the distance from home threw her into a melancholy funk – and inspired Mental Illness’ downbeat first single, ‘Goose Snow Cone’.

“It was snowing so actually it was really beautiful,” she laughs. “I was homesick and jet-lagged. I ended up writing this very pining song. I lived in Boston for 15 years – so I’ve put up with plenty of snow. I’ve just had enough of having to fight the weather. It’s hard enough to be human trying to get your shit together without wearing long underwear from October to April. I was just so over that.

Mental Illness is out now. Aimee Mann plays National Stadium, Dublin on October 28.