Identifying Core Symptoms of Depression for Hawaii Farmers: A Network Analysis for PHQ-9 Screening Tool.

Background: As an occupation, farmers are at high risk for depression and suicide and may exhibit distinctive depression symptom patterns.

Objective: To develop a new version of Patient Health Questionnaire-2 (PHQ-2) for rapid screening for Hawai'i farmers.

Methods: Cross-sectional survey collected Patient Health Questionnaire-9 (PHQ-9) data from 375 Hawai'i farmers. Network analysis included 144 participants with mild to severe depressive symptoms. Gaussian Graphical Models based on Spearman correlations were used to estimate depressive symptom networks, with bootstrapping employed to assess stability, and Receiver Operating Characteristic (ROC) analysis conducted to evaluate the sensitivity and specificity of the new PHQ-2.

Results: Three clusters emerged: Guilt-Mood-Anhedonia, Sleep-Fatigue-Appetite, and Suicide-Motor-Focus. Guilt and fatigue were central symptoms with high values across strength, closeness, betweenness, and expected influence. The new PHQ-2 (guilt and fatigue) demonstrated good validity (AUC = 0.883) and reliability (α =0.632).

Conclusions: The new PHQ-2 showed strong psychometric properties, providing a rapid screening tool for underserved populations of farmers. Findings have broader implications for addressing mental health needs in vulnerable communities globally.