The test, a novel combination of four items from the PHQ-9 questionnaire, performs as well as three longer questionnaires at detecting relapse of major depression and takes a fraction of the time to complete.
It could help GPs monitor at-risk patients more easily while increasing the numbers benefiting from treatment.
But researchers said the findings needed to be replicated in further studies before the test can be recommended.
The PHQ-9 and Hospital Anxiety and Depression Scale depression subscale (HADS-D) questionnaires are widely used in primary care and are effective at screening for depression.
But these tests show mixed performance in correctly diagnosing major depressive disorder (MDD) in primary care. Researchers said that despite widespread use of screening questionnaires, detection of first onset of MDD and relapse remains poor and GPs have questioned the 'validity and utility' of the measures.
In addition, the tests range from seven to 21 items long, and can take 3-5 minutes to complete; up to half of a consultation slot.
In the study, published in the British Journal of General Practice, researchers from the Cardiff University School of Medicine compared the effectiveness of the PHQ-9, the HADS-D, and the Beck Depression Inventory tests.
Researchers investigated how well these could identify depression relapse among 337 patients in Wales with recurrent MDD. They then compared the results to performance of the PHQ-2 test – a shorter version of the PHQ-9 test – as well as a novel combination of four questions from this test.
Patients completed the written questionnaires and also underwent a psychiatric interview. A total of 272 participants took part in all tests, of whom 22.2% had depression within the past month as diagnosed in the interview.
Analyses confirmed that all three long-form tests performed equally well at detecting MDD relapse.
Although the PHQ-2 questionnaire did not perform as well, it matched the performance of the longer tests after two items – on concentration and feeling slowed down or restless – were added.
Study authors said that, as time is a major obstacle in consultations, the shorter test with easily recalled questions had ‘considerable’ advantages over longer measures.
They said: ‘Using a short measure allows the clinician time to incorporate these responses into the framework of a normal consultation [and] so may be more acceptable and may result in a higher level of use. This brief measure may be even more valuable in the presence of multimorbidity.’