Residual symptoms and their associated factors among Thai patients with depression: a multihospital-based survey

Depression is a common and debilitating disease, and even residual symptoms of depression can cause significant functional impairment. To achieve normal functioning, residual symptoms should also be identified and targeted by a competent treatment strategy. Thus, this study aimed to examine residual symptoms of depression and their associated factors among patients with depression.

A cross-sectional study surveyed Thai patients with depression at two psychiatric outpatient clinics, Songklanagarind Hospital, and Songkhla hospital; from June to October 2021. The questionnaires inquired about: (1) demographic information, (2) the PHQ-9 Thai version, (3) a questionnaire focusing on depressive symptoms that impacted daily life, and were originally expected to be improved due to antidepressants. All data were analyzed using descriptive statistics, and associated factors concerning depressive symptoms were analyzed by a Chi-square and a logistic regression.

Of all 566 respondents, the majority of them were female (75.4%). The overall mean age was 43.8 ± 18.1 years. The depressive symptoms that had high frequency, high impact on daily life, and that the participants expected that they are resolved or get better via antidepressants were: sleeping problems (81.6%), feeling depressed (79.9%), and lack of pleasure (75.4%). Most of the participants (65.7%) received one type of antidepressant, and the most prescribed antidepressants were selective serotonin reuptake inhibitors (51.1%). In regard to objectives, 45.4% of participants reported having residual depressive symptoms which included sleeping problems (71.2%), feeling down (62.6%), lack of pleasure (62.3%), and poor appetite (61.9%). The associated factors relating to residual depressive symptoms were younger age, high education level, and having physical illness.

Almost half of patients with depression had residual symptoms, and they showed symptoms with high individual variability. Further to receiving effective treatment, a focused and individualized approach aiming for symptomatic remission, functional recovery, and quality of life improvements is key to recovery. Therefore, shared decision-making, and taking into account drug efficacy based on symptom profiles are both highly recommended.