Common depression screening tool 'better than expected' for identifying suicidal ideation

Key takeaways:

• The PHQ-9 was more effective than suicidal ideation screening in identifying patients who would attempt suicide in the next 3 months.
• PCPs should continue using this common tool to identify patients in need.

A commonly used depression screening tool was better at identifying patients who would attempt suicide in the next 3 months than screening tools specifically asking about suicidal ideation, according to an expert.

“More than half of suicide decedents in the U.S. visit a primary care clinic in the year prior to their death,” Craig J. Bryan, PsyD, ABPP, clinical psychologist, professor and director of the division of recovery and resilience at The Ohio State’s department of psychiatry and behavioral health, told Healio. “Primary care clinics are also more likely to be visited by a suicide decedent than a mental health clinic.”

Because of this, some suicide prevention advocates have encouraged universal screening — the expansion of screening for suicidal ideation (SI) to all patients regardless of why they are visiting.

However, “the U.S. Preventive Services Task Force has determined there is insufficient scientific evidence to recommend for or against universal screening,” he explained. “We, therefore, designed this study to obtain some of the evidence needed to evaluate the effectiveness of universal screening for suicidal ideation in primary care.”

The researchers included 2,475 military personnel, retirees and family members from six military primary care clinics in their analysis. During routine clinic visits, they administered multiple screening tools — including parts of the Patient Health Questionnaire (PHQ) like the PHQ-2, PHQ-8 and the ninth item of the PHQ, or the entire assessment (PHQ-9). The first eight items of the questionnaire focus on individual symptoms of major depressive disorder, whereas the ninth item screens SI. Patients were also screened specifically for SI by being asked, “Have you ever had thoughts of killing yourself?”

The researchers conducted follow-up phone interviews with patients for a year afterward.

Bryan and colleagues found that depression screening with the PHQ-9 was the most effective strategy for correctly identifying patients who would attempt suicide in the near term — more effective than screening tools specifically asking about SI, which he said “is not what we expected.”

“Many researchers have argued for added screening based on the assumption that depression screening is not accurate enough to identify at-risk patients,” he said. “Our findings contradict this perspective. Because depression screening is very common in primary care, our findings suggest that this common practice may be better than expected.”

The researchers additionally noted that more than 65% of patients who screened positive for SI also screened positive for depression on the PHQ-9.

Although the PHQ-9 correctly identified more patients who attempted suicide within 3 months, the SI screening item was better at identifying patients who would commit suicide in the long term (within 6 and 12 months).

“Primary care physicians will sometimes use a shortened version of the PHQ-9 — the PHQ-2 — to screen for depression in clinical practice. If patients screen positive for depression on the PHQ-2, physicians will then follow-up with the full PHQ-9,” Bryan concluded. “Our results suggest that administering the full PHQ-9 may be better than the PHQ-2 for the purposes of screening for suicide risk. Administering the full PHQ-9 is, therefore, a reasonably simple and low-cost way for clinicians to continue screening for depression while also improving their ability to identify those patients who are most likely to attempt suicide in the near term.”