Dr Gabor Maté, an expert on childhood trauma, says adverse childhood experiences can distort development in multiple ways.

Speaking to Scotland Tonight ahead of a childhood adversity conference in Glasgow, he said "the effects can be lifelong and can lead to physiological and mental illness".

Awareness of Adverse Childhood Experiences (ACEs) has become a national public health priority in Scotland.

The concept has been adopted by - among others - the Scottish Government, teachers and the police.

Dr Maté's personal traumatic childhood experiences have impacted his research, work and self development.

He was a Jewish child in Nazi occupied Budapest where he said his mother lived in daily fear for their lives. His grandparents were killed in Auschwitz.

Here is an edited transcript of the interview.

Rona Dougall: So, childhood trauma can be emotional, physical, psychological, but what is the lifelong impact of having a childhood trauma?

Dr Gabor Maté: Trauma affects how you feel about yourself. Generally the child takes things personally. When bad things happen to the child they believe it was their bad, so they have a lifelong sense of shame. Trauma affects brain development. So the brain circuits that regulate emotions, stress, body modulation, social relationships, insight, self-regulation, impulse control. These circuits physiologically are distorted in their development under conditions of trauma. And trauma also gives a person a sense of a world where they don't not belong, where they're not safe, where they're not going to find help. And where they have difficulty trusting other people or on the other hand they trust some people too much when they shouldn't. So it distorts development in multiple ways. And these effects can be lifelong and they can lead to physiological and mental illness.

Rona: Is it inevitable, though, that someone who has suffered childhood trauma will go on to have problems? I mean, presumably some of them don't.

Gabor: It's not inevitable, but the more trauma or the more difficulty you experience, the greater risk of these problems accruing and then cropping up in adult life. Now, if a child has a traumatic experience but has a nurturing adult or a trustworthy mentor, that can mitigate the trauma and promote resilience. But what we can say is that the more negative experiences a child has, or the less positive experiences they have, the greater the risk as adults along the whole range of health concerns.

Rona: And it can happen at a really early age, can't it? As babies in the womb even.

Gabor: We know now from multiple studies internationally that when women are stressed during pregnancy, that has a negative effect on the child's brain development. It makes the child more at risk for addiction, mental health issues, behaviour problems and so on. So really the prevention of mental health problems needs to begin at the first prenatal visit, when dealing with the stresses on the woman. We know this from multiple human studies and animal studies in the laboratory.

Rona: And you bring your experiences to your work, don't you? Because you suffered trauma as a baby.

Gabor: I was an infant, a Jewish infant, under the Nazi occupation in Hungary, in Budapest. My parents were killed in Auschwitz and I lived my first year with a mother who was deprived of her husband, had lost her parents and who was in daily fear for our lives. So that had a huge impact on my own development and that showed up in my adult life, in my relationship, in my work. And very much in my relationship to myself.

Rona: And when you were a baby, your mum took you to a doctor and the doctor said something very interesting about babies like you?

Gabor: The Germans occupied Hungary when I was two months old. I think it was 15 March 1944. And the day after the Germans marched into Budapest, my mother phoned the paediatrician to say "Would you please come and see Gabor because he is crying all the time?" And the paediatrician said "Of course I will see him but I should tell you all my Jewish babies are crying." This simply indicates the exquisite sensitivity of infants to the nurturing adults' emotional states. So that the child's health really depends on the emotional health and social support that the parent has. So in a society, or in a situation, where there is less support, more isolation and more stress on parents, you're going to get more and more troubled children, which is what we are seeing across the western world right now. And all these diagnoses that we are seeing with ADHD, which I wouldn't diagnose, by the way, personally, mental health problems, anxiety and so on, increasing violence, the autism problems. These are related to, not bad parenting, not parents who are mean parents, parents who are not loving but who are stressed and they don't get the support they need.

Rona: Increasingly we are seeing more problems burgeoning in the childhood population. And we use this term now, adverse childhood experiences, commonly known as ACEs, how useful is it to use that term? Is it reductive, do you think?

Gabor: It's not reductive, it's simply a statistical fact that you can't argue with. Which is that an adverse childhood experience is physical, sexual or emotional abuse, violence in the family, a parent being mentally ill, a parent being jailed, being addicted and divorce. For each of these adverse childhood experiences, statistically the risk for adult problems such as mental health issues, psychosis, ADHD, addiction, autoimmune disease, malignancy, go up. Now, the childhood experiences don't explain why these things happen, that has to do with physiological and psychological development, but they provide a statistical grounding for us to know that in order to raise healthy children we have to prevent as much as we can these adversities from occurring.

Rona: But to use this term ACEs, could it not stigmatise people to say that you've got ACEs? Could it also not almost be a self-fulfilling prophecy, that if you have so many ACEs, you are not going to achieve in life?

Gabor: No, it's not a prophecy. What would you rather believe, by the way, if you come to me as an addicted person, that you're addicted because you're a moral failure or you're addicted because you've got this incurable genetic disease, or you're addicted because you have so much pain because of your childhood experiences and if you deal with that pain you can heal your addiction? So the adverse childhood experiences, we actually know, there is a study that showed that in a medical office, when people are asked about their childhood experiences like that, they have fewer doctor's visits later on because just the fact of being listened to and having their experiences validated makes them less prone to get ill. So this is not reductive, it doesn't stigmatise; it simply helps people understand their experience.

Rona: So how do we best support people, then, who have suffered from childhood trauma?

Gabor: First of all, by not blaming them. So if you take the addicted population, I worked with a heavily addicted population in Canada. They're stigmatised, they're ostracised, they're illegalised, they are beyond the pale. What if we saw them as people who have suffered tremendously in childhood, whose addictions, whether it is to sex or gambling or shopping or drugs or alcohol, the 4,000 or 5,000 people every year in Scotland who die because of alcohol related diseases, what if we didn't see them as derelicts or as failures, what if we see them as people who have suffered and who need support to heal their suffering? And then maybe they can give up their addictive habits. So this is a very hopeful perspective. It actually means we can do something as opposed to this unscientific genetic idea that addictions are due to inheritance.