Talking to a psychologist on the phone as therapy for depression may work as well as meeting face-to-face, according to a new study.

Depression is common in the general population and psychotherapy is considered an effective treatment that some patients prefer to antidepressant medications.

The convenience of phones could make psychotherapy more readily available. (Charles Rex Arbogast/Associated Press)

But about 75 per cent of patients with depression in previous studies said barriers like time constraints, lack of available and accessible services, transportation problems and cost stop them from going for treatment.

In Wednesday's issue of the Journal of the American Medical Association, researchers compared treatments by randomly assigning 325 patients at community clinics in Chicago to face-to-face therapy or telephone therapy for 18 weeks.

"Our study found psychotherapy conveniently provided by telephone to patients wherever they are is effective and reduces dropout," the study's lead author, David Mohr, a professor of preventive medicine at Northwestern University Feinberg School of Medicine in Chicago, said in a release.

The results showed 20.9 per cent of the people who had therapy over the phone dropped out compared with 32.7 per cent for face-to-face therapy.

But those in the telephone group scored three points higher on a depression scale than those who met in person.

"The three point difference is of questionable clinical significance but it raises the question whether some individuals are at risk of worsening after treatment with telephone therapy compared to face-to-face," Mohr said.

Overcoming barriers to treatment

The slight worsening could've been because those receiving phone treatment had more mental health difficulties and would've dropped out of in-person sessions altogether.

The possibility that face-to-face treatments creates better results for some can't be ruled out, Mohr said. Physical presence could increase resilience or help people maintain their skills after treatment ends.

"The telephone offers the opportunity to extend care to populations that are difficult to reach, such as rural populations, patients with chronic illnesses and disabilities, and individuals who otherwise have barriers to treatment," the study's authors concluded.

"However, the increased risk of post-treatment deterioration in telephone-delivered treatment relative to face-to-face treatment underscores the importance of continued monitoring of depressive symptoms even after successful treatment."

The researchers couldn't think of any reasons why the findings wouldn't apply to psychotherapy for other illnesses such as a anxiety disorders but that wasn't specifically tested.

They were unable to mask the patients to the treatment, which could affect bias the results.

The research was funded by the U.S. National Institute of Mental Health of the National Institutes of Health.