One in five Canadians will experience a mental illness in their lifetime and by age 40 about 50 per cent of the population will have or have had one.

Mental illness includes conditions such as depression, schizophrenia or bipolar disorder, which “can really affect the ability of an individual to function,” said Nida Mian, senior pharmacy benefit strategist at Sun Life Assurance Co., during Benefits Canada’s Face to Face in Drug Plan Management Forum in December.

Sun Life’s analysis showed that, although mental-health drug claims have been increasing, this trend appears to have stabilized. “Mental-health drugs are unlikely to be a primary cost driver on your benefits plan,” she said.

Read: Health benefits claims paid out to support mental health rose 24% in 2020: CLHIA

Year-over-year percentage growth in mental-health drug plan spend showed 2020 had the highest annual growth. According to Mian, this is “consistent with the increasing rates of mental illness that we were seeing in the population due to the COVID-19 pandemic.”

While mental-health drug spend continues to grow, the share of mental-health drug costs relative to all other drugs has been stable year to year since 2017. “For every $100 spent on a drug plan, seven of those dollars are for mental-health drugs,” she said, noting drugs for depression are the largest driver of mental-health drug claims.

While claims for chronic conditions remained relatively stable, there’s been an increase in claims for mental-health drugs since 2018 due to the pandemic. Sun Life expects claims for mental-health drugs to increase even further due to a variety of factors, such as individuals who are part of the backlog waiting to see a practitioner to get a diagnosis and start therapy.

An analysis of distribution of mental-health claims by age showed mental-health drugs were the primary driver of claims for individuals under age 30. Although mental illness can affect individuals of any age, Mian noted that “it typically onsets in the teenage years or early adulthood and we see that reflected in the data.”

Read: Coverage of the 2021 Mental Health Summit

The top 10 mental-health drugs for 2020 were virtually identical to 2019. Most of the drugs were generic or multisource brand drugs that have lower cost generic equivalents. Trintellix is a higher cost top 10 drug because it’s the only single source product with no generic alternatives.

The impact of generics has changed significantly over the last five years. In 2016, generics accounted for 64 per cent of mental-health drug claims and 27 per cent of the costs were primarily for single source drugs. In 2021, generics accounted for 87 per cent of claims and 67 per cent of the costs. “We can expect this trend of increased generic penetration to continue,” said Mian, noting generic launches over the next few years will offer significant savings to plans with mandatory generic substitution.

Spravato, the first specialty drug for mental health, was launched in 2020. It’s a nasal spray for treatment-resistant depression that comes at a much higher price tag than traditional mental-health treatments. Most plans cover it through a prior authorization program to ensure it’s being used appropriately, said Mian.

Read: A look at using pharmacogenetic testing in determining depression treatment

Pharmacogenomic testing could play a critical role in supporting the overall sustainability of mental-health drugs, she added. Research shows that only a third of individuals suffering from depression respond to the first antidepressant they’re prescribed and it typically takes between two and six weeks for an antidepressant to have an effect. This “could take a significant toll on an individual,” said Mian.

Pharmacogenomic testing can significantly reduce the time it takes for someone to find the most effective medication, she added. “If this is not something you have on your plan today, I strongly recommend taking a look to see if you can add it.”

Read more coverage of the 2021 Face to Face in Drug Plan Management Forum.