Growing up in Canada, her father's delusions and paranoia gave Julia Shaw a front-row seat into an alternate reality Believing "they” were out to get him – including everyone from aliens to the Bin Laden family – he would later email her, warning that she too was targeted by those monitoring him. He believed that doctors too were part of the conspiracy - so has never had a diagnosis from a psychiatrist. Witnessing her father experiencing a parallel "reality" inspired Julia to look into the mind and she had a "lightbulb moment" at university studying psychology when she first heard a description of paranoid schizophrenia. We hear from Julia and her mum as they meet up, driving through Canada.

The well-known "positive" signs of a psychotic episode like hallucinations, paranoia and deluded thoughts can feel frightening to witness but Julia learns how the some families find it hardest to live with the "negative" symptoms like a Iack of motivation and difficulty in concentrating.

Julia talks to families who understand the demands of living with someone who has serious delusions – to hear what helped them to look after themselves as well as their loved one. We hear from Philippa whose son had his first episode of psychosis when he was at university. Although he now has the right medication to control his symptoms he struggles to motivate himself and a troubling side effect is weight gain which puts him at risk of physical health problems. Kate was only 11 when her cool, older brother Sean first showed the signs of schizophrenia. After numerous spells in hospital she remembers how he struggled to look after himself back in the community and became homeless, sometimes going missing Both women found support from Rethink Mental Illness, a charity which helps people severely affected by mental illness to improve their lives.

Kirsty was 8 years old when she started going to workshops with her dad at the Our Time charity, which supports any child with a parent affected by mental illness. She says that role play and talking openly with others about mental health helped to prepare her for when her dad had a psychotic episode on her 13th birthday: although it was frightening she recognised the signs and knew that they wouldn't last.

Another concern for Julia was the increased risk for family members who might inherit a disorder like paranoid schizophrenia. Dr Rick Adams explains how the risk is higher - at around 10%, it does mean there's a much higher likelihood that she hasn't inherited it.

One voice Julia feels is missing is that of the person who hears voices and believes them: she hasn't been able to reach her father. Instead she talks to Ashley who's 25 and is living with a diagnosis of paranoid schizophrenia. Ashley explains how her voices were always male and it it's not a good idea for loved ones to tell a person having hallucinations that they're not real: they have to find this out for themselves. She says that educating herself about mental illness and her faith have helped her to keep calm, along with support from her family.

Like the other families she's spoken to Julia feels guilt about her father and wonders if she could have done more to help him - but hearing about support from charities makes her hopeful. And despite all the difficulties, she also recognises how he has passed onto her a love of learning and to stand up for herself.

Presenter: Julia Shaw