Study looks at link between substance use and psychosis during pandemic

It will be years before the long-term effects of COVID-19 are fully understood, but Dr. Jason Morrison already knows one aspect that needs further study.

In the months after a state of emergency was declared in Nova Scotia and widespread lockdowns were initiated, the interim chief of psychiatry for Nova Scotia Health's central zone said in-patient doctors started noticing changes in who was coming to hospital.

Total admissions to the acute care psychiatric units at the QEII Health Sciences Centre were about the same in the early weeks of the pandemic (March 22 to June 5) as compared to a similar period of time before the state of emergency was called (Jan. 5 to March 21).

However, Morrison said doctors found a notable increase in patients between the ages of 35 and 44 presenting with psychosis in those early COVID days. The frequency where substance use was thought to be a contributing factor was also higher than usual.

An 'unusual' development

"Typically, we see someone with the first episode of psychosis in their teens or their 20s, so to see previously well people with no psychiatric history developing a first psychosis in their 30s and 40s was very unusual," said Morrison.

It was that finding and the increased association with drug use — in particular cannabis and cocaine — that caused Morrison's team at the hospital to decide to take a closer look.

Dr. Nadine Nejati, a second-year psychiatry resident at Dalhousie University, was part of the research team. While the numbers cover all admissions in the Halifax area during the respective time periods, the sample size remains small enough that Nejati said additional research and study is required.

The findings could suggest people are using substances differently during the pandemic, and further research could look at whether that's a coping mechanism for stress or whether there are vulnerabilities in that demographic that have not been previously recognized, said Nejati.

"Important next steps for us is to conduct further research to gain an understanding of what specific changes were, and also to raise public awareness that ... changing one's substance use in this time when people use that as a coping mechanism to perhaps deal with some of the various stressors, that it can have significant implications for mental illness," said Nejati.

Findings came as a surprise

Morrison said there is lots of research when it comes to substance-related psychosis in young people who use daily, but the surprise was the findings for patients between 35 and 44 years old.

"We typically say if you're going to start smoking cannabis a lot, wait until you're after 25 at least, and I think this study kind of made us pause a little bit about that," he said.

If people are going to be using cannabis daily, Morrison recommends they consider products with lower THC levels.