The family of a woman originally from Saint John says they haven’t seen her in more than four months, resulting in a public appeal for information.

Shannon Mary Sullivan suddenly left her job in Toronto back in mid-February, taking all of her things from her condo. Her family says it was highly unusual for her to do that.

"Sick to my stomach,” says Sullivan’s brother, Terence Sullivan. “It keeps me awake at night. It makes me wonder where she is."

Terence Sullivan says his sister had an accomplished career in pharmacology. He says Shannon is a kind, intelligent and avid traveller.

"She hasn't been on social media. There's limited information you can get from her banks, but there's been zero activity on Shannon," Terence Sullivan says.

A few early messages in late February from Shannon indicated she was fearful for her financial security and that her electronic devices might have been hacked. Toronto police determined she rented a car from the Amsterdam airport in early March, but abandoned it in a mall parking lot shortly after.

“In the email that Shannon sends to her employer in February regarding this issue, she feels that someone has entered the vehicle and perhaps tampered with it. She doesn't feel safe to go back into the vehicle," says Terence Sullivan.

Shannon's longtime friends have also tried to reach out to her multiple times with no response.

"The limited contact she had early on were all quite concerning, suggesting to me that she wasn't ok, that she is in a state of distress," says Shannon’s friend Nadine Blum.

"She's very much an introvert,” says Shannon’s friend Elsie Yu. “I can see how she would do that, but ... she does have some friends that she can talk to."

Terence has made a trip to Toronto to meet with Shannon's employer, the police and her property manager. He says based on the evidence he and his family has gathered, they believe Shannon is under mental duress.

"We believe no one has her. She's not under duress that way. However, the fact that her mental faculties have been compromised almost certainly led a greater sense of urgency into finding her," Terence says.

Shannon's family and friends have set up a Facebook page hoping to find her and bring her home safe.

With files from CTV Atlantic’s Mary Cranston.