Study Findings

A total of 73 people with obesity (82.2% women) were given an information sheet about the project and a consent form, and underwent PHQ-2 screening, which was administered in the examination room by the author. Participation was voluntary. If the PHQ-2 was positive, with a score of ≥3, the PHQ-9 was administered. Completed PHQ-9 forms were scored and patients were notified if further mediation was indicated (Table).13 All patients were offered referral to a nutritionist and advised to follow up for weight loss evaluation and management.

Table. Scoring System for PHQ-913

Score Severity Treatment
0-4 Minimal No action
5-9 Mild Watchful waiting
10-14 Moderate Counseling and/or treatment initiation
15-27 Moderately severe to severe Treatment initiation and refer to psychiatry

Of the 73 patients, 18 (24.7%) screened positive for depression on the PHQ-2 and 24 patients (32.9%) reported being on an antidepressant. Approximately 12.3% of the 18 patients with a positive PHQ-2 questionnaire returned to the clinic for weight loss evaluation and management, 6.8% accepted a referral for psychiatric examination, and 8.2% accepted a referral to a nutritionist. Most of these patients had a BMI between 30 and 34.9 mg/kg2 and 64.4% were middle aged (age range, 40-59 years).

The 55 patients who screened negative for depression (PHQ-2 score <3) had a BMI between 30.5 and 66.1 mg/kg2, ages 20 to 59 years. Of this subset, 21.8% reported being on antidepressant medications and 34.5% reported a history of depression. Only 9.1% of those who were not depressed returned to the clinic for weight loss management and 5.5% accepted a referral to a nutritionist.

Patients who tested positive on the PHQ-2 were given the PHQ-9. The BMI range for this group was 31.1 to 43.7 mg/kg2 and their ages ranged from 18 to 58 years. All patients who were given the PHQ-9 screening received further evaluation during the office visit; 27.8% of patients who scored 10 or more accepted a referral for psychiatric evaluation and 16.7% were newly identified with depression. Most patients (61.1%) who took the PHQ-9 were already taking an antidepressant. Only 22.2% of patients identified with depression returned to the clinic for weight loss management, and 16.7% accepted a referral to a nutritionist. Results of the PHQ-9 for depression showed no scores of minimal depression, 11.1% with mild depression, 38.9% with moderate depression, 44.4% with moderately severe depression, and 5.6% with severe depression.

Three statistically significant finding were discovered during the data analysis. The first showed that the distribution of patients with a history of depression was different between the PHQ-2 and PHQ-9 groups (P <.0001). Second, the distribution of patients who were on antidepressants was significantly different between the PHQ-2 and PHQ-9 groups (P =.001). Third, the distribution of patients who agreed to a psychiatry referral was also significantly different between the PHQ-2 and PHQ-9 groups (P =.001).

The study found no significant difference in the diagnosis of depression between the sexes (P =.498). The distribution of patients with obesity who agreed to a nutritionist referral was not significantly different between the PHQ-2 and PHQ-9 groups (P =.092). The distribution of patients who returned for weight loss management (P =.211), patients in different BMI classes (P =.449), and patients in different age groups (P =.405) were not significantly different between the PHQ-2 and PHQ-9 groups.

While not statistically significant, trends were noted in the findings. Approximately 40% of patients who took only the PHQ-2 (negative for depression) had a BMI of 30 to 34.9 mg/kg2,while 39% of patients who took the PHQ-9 (positive for depression) had a BMI of 35 to 39.9 mg/kg2. In addition, 9% of patients who screened negative for depression returned for weight loss management vs 22.2% of patients who screened positive for depression. Finally, 5.5% of patients who only took the PHQ-2 accepted a referral to a nutritionist, whereas 16.7% of patients who took the PHQ-9 accepted the nutritionist referral.