Denise Mina mimes putting in a pair of earbuds as she describes the pivotal plotline in her new novel – a true crime podcast. “There is something very intimate about hearing the story told to you while you’re doing other things,” she explains.

It is this intimacy that Anna McDonald, the protagonist of Mina’s latest murder mystery Conviction, is craving. Anna listens to the first episode in the kitchen of her elegant house in Glasgow’s West End: the podcast is a twisty tale of a sunken yacht, family annihilation and a super-rich heiress. Then it dawns on her that this story revolves around the death of a man she once knew, who links her back to a crime she has been running from for more than a decade. Conviction is Mina’s 15th book since her 1998 debut Garnethill, but to describe her as a crime novelist can seem limiting. She is also a playwright, for stage and television, and is currently adapting a play for Edinburgh’s Lyceum. She has scripted many graphic novels, becoming the first woman to write 12 instalments of the comic-book series Hellblazer, and is planning a second series of a roadtrip for Sky Arts in which she and Frank Skinner explore Scotland in the footsteps of Boswell and Johnson. She’s writing another novel, based around notorious murders of sex workers in Glasgow in the 1990s, while a top secret true crime project will be revealed later this year.

“I’ve got a little bit too much on,” she concludes. “But it’s great isn’t it? I think it’s really important to remember to be grateful. The longer I go on I realise what a miracle it is to have a career as a writer.”

In print, as in person, Mina brings a weight of tenderness to her work that is authentic as well as appealing. The 52-year-old is cherished by readers and genre contemporaries alike – she was inducted into the Crime Writers’ Association hall of fame in 2014 – and younger writers in particular speak warmly of her generosity. There are few avenging angels or master criminals in her work, only flawed human beings whose violence is clumsy, who bicker with their pals and feel hungry on a regular basis.

Glasgow’s West End: ‘I’m not from here. I live here and I observe here, but I don’t feel Glaswegian.’ Photograph: Jane Barlow/PA

Although there is a rollercoaster, cross-continental murder mystery at its backbone, the muscle and sinew of Conviction are satisfyingly substantial themes about the sustainability of self-invention, and how possible or desirable it is to tell the truth about oneself in the social media age, as well as a subplot that reflects the core concerns of the #MeToo movement. Mina is admired for her deft handling of questions of conscience and culture – and women’s responses to them – as much as her ability to write a cracking story. And she has occupied this territory from the very start: the trilogy that began with Garnethill, set around the dilapidated tenements of Glasgow city centre, encompasses intergenerational alcoholism, incest and mental illness.

“Crime writing is a way into those subjects and the way it’s received is very important,” she says intently. “That’s why a lot of feminist writers are writing crime fiction, because it is consumed quickly and widely. And if you want abused women to be anything other than passive then you need to tell stories about them as active characters.” She says, “the vast majority of readers are women, and now it’s 50/50 men and women writers, so it’s really egalitarian because it’s the market.”

This was not always the case. When Mina was starting out in the late 90s, the crime readership could be said to be acclimatising to female protagonists – such as Val McDermid’s journalist sleuth Lindsay Gordon, first published by the Women’s Press in 1987, Frances Fyfield’s London lawyer Sarah Fortune, or US colossus Sue Grafton’s private investigator Kinsey Millhone.

But still, Garnethill’s heroine Maureen O’Donnell, a heavy drinking survivor of childhood sexual abuse and recent psychiatric inpatient, was – in market terms, as Mina might have it – unpromising. That Maureen was embraced by publishers, then by readers and multiple awards panels, across three books, is testament to the strength of her creator’s writing. Reading about Maureen back then was like taking a shot of pure Glasgow womanhood. The writing scene is certainly more feminised these days and Scottish crime fiction has a host of strong female protagonists from writers such as Lin Anderson, Alanna Knight, Manda Scott and Karen Campbell.

As an older writer, you become more disinhibited and think it’s all right if readers don’t agree with you

“When I wrote Garnethill, someone interviewed me and asked: ‘So you’ve got a female protagonist, are you a feminist?’, which was a really bad thing to be in 1998. Then after [the TV series] The Killing came out, someone said: ‘There’s a female protagonist again, don’t you think that’s a bit of a cliche?’ That’s great!” she laughs. “That means it’s becoming a familiar trope. We’re still ‘other’, but it’s becoming normal within the form. Things have moved on.” She pauses. “We still have the problem of the blond female victim, but that’s cultural.”

Mina laughs a lot in person, her delicate features framed by magnificent and mobile eyebrows. Sitting by the window of a busy Italian deli in Partick, her style is elegant steampunk: heavy boots, flared skirts and funky grey hair. She is a sharp observer, but her judgments are gentle.

Conviction is studded with throwaway observations of startling clarity, for example Anna’s thoughts on survivors of sexual violence: “We are as perennial as love. We go about our business ... We don’t tell our stories because, if we’ve survived, that can only mean that what happened wasn’t so very bad after all. It never means we are fucking amazing.”

“I think it’s about having more confidence as an older writer,” Mina says. “You become more disinhibited and think it’s all right if readers don’t agree with you.” Then again, she adds: “If you’ve got someone’s attention, and you’ve trapped them into listening to you because they’re trying to find out who the murderer is, you can’t bore the tits off them with your view of the world. I think a bit of humility is good in a writer.”

She is blunt about the fact that she prefers to discuss anything other than herself: “I’m always slightly surprised – it’s as if someone’s stumbled on me masturbating – when I have to talk about my books.”

‘Hands off our Parliament’ demonstration in Edinburgh, June 2018. Photograph: Jane Barlow/PA

She plainly relishes talking about ideas though, an answer about the inspiration for her podcasting plotline looping into her thoughts on western society’s addiction to narrative. Podcasts are fascinating, she says, because they are as yet unregulated, often run by those outside traditional structures, at a time when people are very suspicious of the filters through which mainstream media operate. “The amount and the quality of stuff out there is amazing, but there are no ethics. It’s cowboy country – people libelling other people, making unfounded allegations, posses are forming … It’s mental.”

She mentions recent episodes of Stuff to Blow Your Mind, exploring why humans are addicted to certain narrative shapes. “They are so comforting, but it fundamentally impacts the way we receive information. So the anti-vaxxers have a much cleaner story than vaxxers. Everything doesn’t fit into a story, some things are just information.”

After a peripatetic childhood – her father worked as an engineer across Europe – Mina left school at 16. “I couldn’t read until I was about nine; I was a very late developer and I still can’t spell,” she says. “I don’t think it’s about whether you were a born writer but whether you get a buzz off writing.”

She worked in a series of dead-end jobs before settling back in Glasgow, where she still lives with her partner and son. She went to night school to get into Glasgow University where she studied law. She wrote Garnethill when she was supposed to be working on her PhD thesis on the ascription of mental illness to female offenders.

We need to stop flying everywhere and stop eating meat, and neither of those things suit me

Glasgow itself is an imposing element in her writing – the rhythm of the speech, the cadences of the humour, the sometimes restrictive feeling of a small city where family and strangers can become overfamiliar. If a reader were arriving fresh to Mina’s work, one of their early hits really ought to be her last book, The Long Drop, the semi-fictionalised account of the serial killer Peter Manuel and an evocative portrait of Glasgow in the 50s.

“I love Glasgow,” she says firmly, before qualifying: “But I’m not from here. I live here and I observe here, but I don’t feel Glaswegian.”

Before the Scottish independence referendum, Mina said that she thought it was strange for artists to exhibit such a firm notion of national identity as many did in their support for the “yes” campaign, given their outsider status.

“I do still feel like that. A lot of artists don’t feel they could distil their national identity down to one. I don’t even feel it’s limited by Europe. I did grow up in Paris, Amsterdam and London but I don’t really know who is from here. All the artists I know are from other places as well.”

She has also spoken at length in the past about the importance of being a political writer.

“I think it’s massively important. What I wanted to create [with Conviction] was a complete world for people who cannot stand it any more. Because Anna runs away and I think a lot of people are wanting to run, to get the fuck out of here, so I wanted to write a really engaging world for them to be in. I don’t think there’s any such thing as an apolitical writer. Apolitical really is about how close you are to the status quo.”

She reflects on the contrast between the recent chaos in Westminster and the Extinction Rebellion protesters blocking the North Bridge in Edinburgh the day before we meet: “They say we’ve got 12 years, which is a very short time, but it is time. We need to frame it optimistically. We need to stop flying everywhere and stop eating meat, and neither of those things suit me. Either it’s going to be imposed on us by an authoritarian regime in the future, or we do it volitionally now because it’s got to happen. We’ve got to stop digging oil and coal and gas, and change GDP. Why are we measuring how many rifles we can make? But those are great psychic changes, and we’re fighting about David Davis.”

UK politics, she says, has been taken over by party politics: “That’s very acute and that’s the least interesting thing that’s happening in this country. Brexit is not going to be what we talk about in the future.”

• Conviction by Denise Mina is published by Vintage on 16 May. To order a copy, go to guardianbookshop.com. Free UK p&p on orders over £15.