ALISON BRANLEY, REPORTER: Jason Coulstock is on a lucky strike. After all, he's already died three times this year.

Jason had to be revived on multiple occasions in January after being hospitalised with a gall bladder that had turned gangrene.

It was a medical catastrophe that followed a potent drug cocktail.

ROS PHILLIPS, MOTHER: This is the medications that were inside Jason's Webster-pak. This one here is an anti-psychotic. That one is an antipsychotic. This one is an anti-depressant and that one is an antipsychotic.

JASON: Hi mum.

ROS PHILLIPS: How are you?

JASON: Alright. I love you.

ROS PHILLIPS: I love you too.

ALISON BRANLEY: Jason Coulstock has an intellectual disability and autism. He had been living in this New South Wales Government group home last year when his normally good behaviour inexplicably started to deteriorate.

ROS PHILLIPS: He was kicking doors and breaking glass doors. He was attacking staff. He was attacking other clients that live in the house. Wow.

JASON: See, Mum.

ALISON BRANLEY: His mother Ros Phillips, took him to a psychiatrist who prescribed the sedative, lithium.

After a while it seemed to be having an unusually strong impact on Jason.

ROS PHILLIPS: Jason was like he was stoned. He basically couldn't function.

ALISON BRANLEY: Then in January, Jason was rushed to hospital in agony.

ROS PHILLIPS: About an hour after I got to the hospital. Jason had passed away. They brought him back and at that time we realised something was really wrong. They said that the gallbladder needed to be removed. It was gangrene.

ALISON BRANLEY: Jason had to be revived two more times before Ros made a shocking discovery.

ROS PHILLIPS: I looked at his Webster-pak and it was full of medication that I had never seen, and then two days later they came back and that's when they said to me that Jason was suffering with drug-induced toxicity.

ALISON BRANLEY: Neither Ros nor Jason's psychiatrist knew that in addition to the three psychotropic medications he was already taking, Jason had also been put on another antipsychotic and an antidepressant.

Ros says at Jason's group home there were only ever two carers on each shift to care for five men. She worries the pressure might have got to some of them.

ROS PHILLIPS: They were trying to shut him up. Keep him quiet.

PROFESSOR JULIAN TROLLOR, NEUROPSYCHIATRIST, UNSW: We do know that this is a problem. We know that it does need to be addressed.

Hi Michael thanks so much for coming in today.

MICHAEL: You're welcome.

PROFESSOR JULIAN TROLLOR: Most of the antipsychotic medications are predominantly approved for use in schizophrenia and related conditions. A majority of prescriptions are in fact being given for challenging behaviour.

Unfortunately the evidence base for the use of medications and antipsychotics in this manner is very limited.

ALISON BRANLEY: And why do we need to be so careful with these medications?

PROFESSOR JULIAN TROLLOR: The problem we tend to see in people with intellectual disabilities is that they are unable to accurately report or spontaneously report side effects they may be experiencing.

ALISON BRANLEY: A 2010 Victorian Government review found 99 per cent of people with an intellectual disability in its group homes, were on some kind of psychotropic drug, yet only 43 per cent actually had a mental illness.

Jason do you remember being in hospital?

JASON: Yeah.

ALISON BRANLEY: How come you went to hospital?

JASON: I wasn't feeling too well.

ALISON BRANLEY: Do you remember what it was like at your old house?

JASON: I didn't like it there.

ALISON BRANLEY: What kind of stuff made you not like it?

JASON: I just don't like the staff.

ALISON BRANLEY: How come? Did they do something?

JASON: One person. One person. I don't like him.

ALISON BRANLEY: Do you remember them giving you pills?

JASON: Yeah.

ALISON BRANLEY: What happened to you when you took the pills?

JASON: I can't remember Alison.

KYLEE ROBERTS, NSW COUNCIL FOR INTELLECTUAL DISABILITY: A chemical restraint is the use of a medication that restricts the freedom of movement of a person with a disability.

ALISON BRANLEY: Disability advocates say using medications to restrain people is regulated but widely used.

KYLEE ROBERTS: It is often used in cases where they may be at risk of harming themselves.

ROBERT STRIKE, NSW COUNCIL FOR INTELLECTUAL DISABILITY: That's true.

KYLEE ROBERTS: Or somebody else. We believe that it is often used in place of positive behaviour support.

ROBERT STRIKE: They look like they're in another world. Let's put it that way.

It's just words.

KYLEE ROBERTS: So the information is accessible for everyone? So we use pictures and we use big type and not too many words on one page.

ROBERT STRIKE: That's right.

ALISON BRANLEY: Robert Strike sits on the council's board. He's spent time in institutions and regularly talks to people living in group homes.

ROBERT STRIKE: Sometimes people say to me, people with a disability, they say, "I don't like being on these tablets."

And I'm seeing people being punished for the wrong thing. Medicated with the wrong thing sometimes.

ALISON BRANLEY: There's fears in some states doctors don't need a guardian's consent to write a script, even if the drugs are being used outside guidelines.

KYLEE ROBERTS: If the medication is misused, that can become an abuse of a person's human rights.

ALISON BRANLEY: The New South Wales Government told Lateline that Jason's extra medications were determined by medical professionals and approved by Miss Phillips: "FACS (Family and Community Services) finds claims that its staff breached restricted practices to be inconsistent with the records held by the group home."

But Ros says she was told otherwise:

ROS PHILLIPS: "I was told that Jason's records had disappeared and I never approved any extra medication."

ALISON BRANLEY: The GP clinic where Jason was treated says his care was led by his specialists: "Lines of communication with his disability carers and mother were kept open throughout the time he received care."

But Lateline has the referral later from Jason's psychiatrist back to his GP, which makes no reference to the extra meds.

Medical groups say the case highlights systemic problems with coordinating care.

DR KEAN-SENG LIM, VICE PRESIDENT, AMA NSW: One of the big problems with treating someone with any disability is that there are often a lot of very complex needs, there are often a lot of different carers and health providers involved in a person's care.

So there might be several different specialists, several different doctors, and of course there's the patient's family and the patient's carers and any other places the patient may be going to.

So coordinating their care is one of the big challenges and one of the most tricky parts because this needs a lot of time.

ALISON BRANLEY: Group homes are the latest institutional setting where there's fears the drugs are being misused, including aged care, foster care and juvenile justice.

PROFESSOR JULIAN TROLLOR: There's an urgent case for upskilling doctors, nurses and disability professionals in the appropriate use and role of psychotropic medications.

JASON: I got the milk today, Mum.

ROS PHILLIPS: Good boy.

JASON: I made your coffee for you.

ROS PHILLIPS: Thank you.

ALISON BRANLEY: After he was discharged from hospital, Jason moved into a privately run home on his own.

He makes a beautiful cup of coffee when I come here now, which he has never done that.

ROS PHILLIPS: Good boy. Thank you.

JASON: That's mine.

ROS PHILLIPS: The State Government group home is disgusting.

It needs a complete overhaul. From the first year that Jason was in care, he's been assaulted, he's been starved, he's not been given good care, he's been neglected. It has been 16 years of hell.

I feel like I've been in a nightmare and just haven't been able to wake up.