Colbey had depression for years. Then a little-known supplement pulled him out of the darkness.

For 24-hour crisis support, please contact Lifeline on 13 11 14.

Five months or so ago, Michelle Watkins was downstairs in her home in Macleod, Melbourne, when she heard a commotion coming from the floor above.

“With five children in the house I’m so used to going upstairs and being like, ‘Right! What’s going on? Who started it?’ But this time I crept up the stairs quietly,” the naturopath told Mamamia.

There she saw her 15-year-old son Colbey having a pillow fight with his 12-year-old sister and step-sister.

“He’s laying in wait for them, and he thinks it’s hysterical. He’s giggling his head off,” Michelle said. “I wanted to cry. When I looked back on it I realised that was the first time I’d heard a real laugh from him in five years. It was just such relief. It was like my son was coming back.”

After years of mental health struggles and two on antidepressants, the teen was finally emerging from the darkness. Michelle attributes her son’s return to one relatively simple thing: L-methylfolate, a formulation of folate that researches are heralding as a promising adjunct to antidepressant medication.

For Colbey, it was just ten days after he began taking the supplement that his mother started noticing improvements.

"Everything was expressed as anger."

As a toddler, Colbey Alderson was a cheeky little kid. Always on the go, he had his hands in everything. But when he reached primary school, things changed.

"I started to notice that he wasn't as outgoing," Michelle said. "He wasn't making friends as easily, he was struggling with his learning.

"Everything was expressed as anger and was exaggerated and over the top. He went straight from happy to angry."

With the collapse of his parents' marriage in Year One, Colbey's behaviour became even worse; rage and negativity became his default response. There were investigations with speech pathologists and psychologists over the next two years, but all were reluctant to put a label on someone so young. "Anxiety issues" was as much as Michelle was told.

"I was just kind of holding it together. I'd think, 'Well, it's not that bad. There are kids worse off than him, and if he's a bit angry at home that's OK,'" she said.

"You kind of put it to the back of your brain, because you think kids don't get anxiety and depression. [You think] 'He's just acting out because he's moved school and moved house.' You kind of make excuses for it and just keep going forward."

It wasn't until after Colbey was diagnosed with cancer at the end of Year 4, that he and Michelle learned the truth.

The cancer was Ewing sarcoma, a rare but treatable form of the disease that mostly occurs in and around the bones. What began as a sore arm in late 2012, saw Colbey undergo 15 rounds of five different chemotherapy drugs, bone graft surgery and 12 weeks with a frame to stabilise his bones.

His mental health took a backseat as he fought to regain his physical health.

But one year after it was all over, once Colbey had grappled with the gravity of what he'd been through, doctors were finally willing to put a label on his mental state. In 2013, at the age of 10, he was diagnosed with anxiety and depression. A Post Traumatic Stress Disorder diagnosis followed in 2014.

They finally had an answer. But as Colbey entered his teenage years, and his family blended with Michelle's new partner's, his depressive symptoms reached their depths. He withdrew, locked himself in his room, lashed out.

"Everyone was on tiptoes around Colbey, because of his moods and behaviours. It was, 'Well, Colbey's had cancer'. He really ruled our house. If he was feeling flat or depressed, everyone would be tiptoeing around that," Michelle said.

"There were some quasi suicide attempts. They were a cry of 'This is how bad I'm feeling. It's really, really bad and we need to do something about this.'"

When he was 13, Colbey's psychiatrist placed him on anti-depressant medication. The first failed to curb his anger, the second proved more effective. But it wasn't until he began taking L-methylfolate that his mental health showed significant improvement.

The place for L-methylfolate.

Folate, which is a B-group vitamin, helps in the production of key chemical messengers like serotonin, a shortage of which is implicated in severe depression.

As Mal Hopwood, professor of psychiatry at the University of Melbourne, explained to Mamamia, there is not enough evidence to suggest normal folate supplementation on its own will reduce symptoms for people with depression. The key is L-methylfolate; a targeted formulation that researchers believe is more likely to get into the brain.

"For most Australians, if they eat a relatively healthy diet they should have normal folate levels," he said. "But sometimes it seems that in order to overcome depression, you need more than you can get in a healthy diet. So L-methylfolate aims to boost the levels of folate and hence the levels of serotonin and that increases the impact of our medications."

The research shows that with existing prescription-only treatments the number of adult depression patients who respond to treatment is only one in seven. When taken with 15mg of L-methylfolate as an adjunctive therapy, this increases to one in three.

The word 'adjunctive' is key. There is no evidence to suggest L-methylfolate is effective at combating depressive symptoms on its own. Nor that it will work for everyone with depression.

"Generally where we'd see the place for [L-methylfolate] would be when treatment as usual has not been effective. So antidepressants, for example, have not produced a complete response. Adding in L-methylfolate may increase the likelihood of a complete response," he said.

Prof Hopwood encourages anyone who has a problem with depression to present for help and seek the advice of their doctor.

"Sometimes it can take a little while to find the right combination of things that's going to help you as an individual. It's really great when we have new additions to that range of things we can use and it appears L-methylfolate may be a useful addition," he said.

After five months of taking his L-methylfolate sachet every morning Colbey's symptoms have reduced dramatically.

"There are still periods where we may not get that happy, cheeky Colbey," she said. "But that really cheeky, prank-loving, trouble-making son of mine is back more often than he's not."

The above is not intended to be medical advice. For further information about medications, supplements and mental health, please consult your doctor.

If you need help coping with depression or anxiety, 24-hour crisis support is available via Lifeline. Please call 13 11 14.