Canadian children celebrating Halloween were in for a serious treat during their trick and treating rounds in the neighborhood when a pharmacy accidentally distributed antipsychotics instead of sweets.

The children went to visit a drugstore in Beauport, Quebec City during their rounds and ended up getting bipolar medications. The drugs that got involved in the mix-up are divalproex and quetiapine, both of which are used to treat manic episodes in people with bipolar disorder.

According to the Daily Star, the mix-up happened after a mother of a patient dropped the prescription drugs she got without her knowledge as she was heading out the pharmacy. Another customer who walked in happened to pick up the medications from the floor and placed on the counter close to a basket of candies and treats.

Constable Melissa Cliché, spokesperson for Quebec City police, told the news outlet that an employee may have picked up the medications and thrown them inside the basket, causing the mix-up.

There were seven pills all in all and each one of them is packed in an individual blister, making it look just like an ordinary candy. The report did not mention if the children were able to ingest the pills.

The police explained that taking the pills won't pose serious health consequences, although there are known side effects such as drowsiness, dizziness, and increased suicidal thoughts. Other serious side effects associated with the drugs include confusion, seizures, and fainting.

With this report, it's a good reminder for parents to routinely check their kids' Halloween treats.

This mix-up in children's treats was not the only trick-or-treat-related incident reported for Halloween this year.

Pennsylvania police is also investigating candy bars given to kids on Oct. 31 that reportedly had sewing needles inside them.

In Ohio, a teenage girl also discovered a razor blade inside her Snickers bar.