Working college students were more likely to have mental health problems if they had toxic relationships with co-workers than if they were on friendly terms with colleagues in a small new U.S. study.

“If you think about a typical 24-hour day for a college student, aside from sleeping, students are going to school and studying and also working part-time, four hours a day on average,” lead study author Allison Vaughn, a psychology researcher at San Diego State University, said by email.

“It makes sense that the people a college student works with would also have the potential to be health-relevant,” she added. “Students who need to work their way through school should try to make the most of these workplace relationships, just as you would with any friendship or romantic relationship.”

Many college students work during school, with estimates ranging from 58 percent to 72 percent of undergraduates, Vaughn and colleagues write in the Journal of American College Health. Working at least 20 hours a week is also a reality for 24 percent to 47 percent of these students.

To understand the connection between students’ relationships at work and their mental health, the researchers surveyed 170 working students enrolled in an introductory psychology class in March 2011.

Students ranged in age from 18 to 35, and on average were about 20 years old.

Most participants worked part-time, averaging about 19 hours a week, and had typically held their current jobs for about 15 months.

The questionnaires touched on the quality of relationships with supervisors and up to three co-workers, job satisfaction and mental health issues such as stress, depression and anxiety.

Generally, the students rated their supervisors as being moderately or very helpful and their co-workers as being only slightly upsetting. They described the majority of their work relationships as supportive, or were ambivalent.

Participants who were ambivalent about their supervisors had poorer mental health than their peers who had positive relationships with their bosses.

The students who felt ambivalent also had lower job satisfaction and less support, more thoughts about leaving the job and more burnout.

Results for coworkers were similar, with ambivalent relationships linked to worse mental health.

The students who had more supportive relationships at work had fewer symptoms of stress, lower depression and anxiety and higher satisfaction with life, the authors note.

The study is small, and doesn’t prove a cause-and-effect connection between troubles at work and poor mental health, the researchers caution. It’s also possible that students’ perceptions of their work relationships don’t match up with reality, they acknowledge.

“Perceptions of relationships may be colored by mental health, so it might actually be that students with better mental health or higher self-confidence to start with interpreted relationships at work as being more positive in general,” said Kathy Rospenda, a researcher in psychiatry and psychology at the University of Illinois at Chicago.

Even so, the findings add to a growing body of evidence that negative experiences at work can contribute to mental health problems among students, Rospenda, who wasn’t involved in the study, said by email.

The best time for students to assess whether a job will provide a positive work environment is during the hiring process, said Rebecca Vidourek, a researcher in health promotion and education at the University of Cincinnati in Ohio.

“It is important for students to ask good questions when they interview,” Vidourek, who wasn’t involved in the study, said by email. “Asking about demographics, work climate, flexibility for students, etc. can help determine if a workplace will be a good personal fit.”

Once they’re on the job, challenges in relationships with supervisors or coworkers may also be an opportunity for students to learn communication skills, Paola Pedrelli, a mental health researcher at Massachusetts General Hospital in Boston, said by email.

“Some students may be passive and then resent the responsibilities they have been assigned because they were not assertive or may be aggressive and be reprimanded,” Pedrelli, who wasn’t involved in the study, said by email.

At the same time, students who work more hours also have to be cognizant of how work can impact their mental health, she added.

“Students who work full-time may not have time to sleep, eat well, exercise and engage in pleasant activities,” Pedrelli said. “Neglect of these areas may lead to low energy, irritability, and poor concentration and academic performance and overall dissatisfaction.”