Depression is a common condition that causes significant mental health morbidity, contributes to poor general health, and is associated with lower quality of life. In fact, depression is the leading cause of disability worldwide . The presence of suicidal ideation and trauma symptoms are important to consider in the treatment of depression, as they are common in primary care populations [13, 33, 34, 35] and may impact depression treatment outcomes, even after controlling for their associations with baseline depression. Suicidal ideation may occur as a symptom of a depressive episode or it may occur apart from a depressive episode . Suicidal ideation may also be precipitated by trauma . Relatedly, depression itself may be present co-morbid to, or develop as a consequence of, trauma .
Within this study, referred primary care patients endorsed significant symptoms of depression, with a mean PHQ-9 score of 15.87, indicative of moderately severe depressive symptoms . Strikingly, on intake 40.33% of patients answered affirmatively on PHQ-9 item 9. The high rate of endorsement on PHQ-9 item 9 among those referred to the program underscores the importance of systematic screening for suicidal ideation and safety planning in the population.
The presence of co-morbid behavioral health symptoms at intake appointment was common among patients referred to the BHA program. Unsurprisingly, anxiety symptoms were highly prevalent (70.57% with GAD-7 Score ≥ 10). Previous research has reported that anxiety symptoms and anxiety disorders are commonly present within primary care settings [38, 39]. The presence of elevated anxiety symptoms on intake was associated with lower likelihood of response or remission from depression within 6-months of treatment. Patients with co-morbid depression and anxiety have a decreased likelihood of remission and increased risk of depression and anxiety severity [40, 41] . Past studies have shown those experiencing co-morbidity also have increased impairment in social and occupational functioning and increased rate of suicide attempts than patients not suffering from comorbidity [40,42,43] . High rates of reported substance use were observed in this population as well, with 37.07% of patients endorsing at-risk alcohol use (AUDIT-C Score ≥ 3 for females and ≥ 4 for males), and 10.41% indicating at-risk drug use (DAST-10 Score ≥ 3). Substances may be used as a coping mechanism by patients with behavioral health symptoms [44, 45].
Depression treatment can be examined in terms of a patient’s achievement of response or remission from symptoms and time to treatment outcome. Given the emphasis of the short-term treatment model of the BHA program and increasing emphasis on national quality outcomes monitoring in depression , we focused on treatment outcomes for depression at 6-months of treatment.
Similar to previous research, patients who demonstrated response and remission from depression symptoms at 6-months had lower mean depression symptoms on intake. More severe depressive symptoms are associated with poorer functioning and quality of life  which are both a sequalae of depression and impact patients’ treatment outcomes . Unsurprisingly, the severity of baseline depression symptoms is significantly associated with both response and remission, even after controlling for baseline suicidal ideation, anxiety, and traumatic stress.
Importantly, patients endorsing suicidal ideation on intake were less likely to achieve depression response or remission. Results revealed the odds of remission among patients with suicidal ideation is 0.53 times the odds among patients without suicidal ideation, when controlling for baseline PHQ-8 score, traumatic stress, and anxiety. This is a particularly interesting finding, given presence of suicidal ideation suggests more severe depressive symptoms (higher initial PHQ-9 scores). According to Pompili , there is evidence that suicidality itself may impact treatment response to antidepressant medications, independent of overall depression severity. Further, it is noted that “such evidence seems to suggest that depressed, suicidal individual represent a peculiar subgroup of patients that request in-depth clinical observation” . These results suggest clinicians may find utility in examining suicidality as a separate predictive factor in depression treatment. Patients with suicidality may require more aggressive medication management and therapy. Further research is needed in this area.
On intake, 28.29% of patients had a PCL Score > 50, indicating risk for clinically significant trauma symptoms and possible diagnosis of post-traumatic stress disorder. It has been reported that 2-39% of primary care patients may have a diagnosis of post-traumatic stress disorder (PTSD) [33, 35, 47], with a recent United Kingdom study providing a prevalence estimate of 15.5% . The rate of trauma symptoms reported in this referred population supports these estimates. The presence of trauma symptoms on intake was associated with lower likelihood of remission from depression within 6-months of treatment after controlling for depression symptom severity on intake. Specifically, in terms of impact on depression outcomes, the odds of remission among patients with a baseline PCL score > 50 was 0.45 times the odds of remission among patients with a baseline PCL score ≤ 50. Results were similar in the fully adjusted model (odds ratio = 0.52), although not statistically significant. The lower estimated likelihood of remission from depression in these patients indicates that patients with depression should be screened for trauma symptoms. Psychiatric evaluation of this important symptom domain will further inform depression treatments and these results suggest the need for potentially greater service intensity (number of treatment sessions, frequency of sessions) and/or more targeted therapies and medication management to address co-morbid trauma symptoms and possible PTSD diagnosis. Treatment programs may explore the addition of trauma-focused treatments such as cognitive processing therapy, prolonged exposure, or eye movement desensitization and reprocessing therapies [49, 50].
Additionally, patients with challenges in emotional regulation and those exhibiting self-harm behaviors may also benefit from dialectical behavioral therapy [51, 52]. It is important for providers and health systems to understand patient-related and systems-level factors associated with depression remission and response rates in real-world treatment settings. These factors may be employed to increase specificity of treatment services to help patients achieve remission from depression symptoms.
Highlighting difficulties inherent in using EHR data, we relied on system labels to define baseline and follow-up visits. This includes identifying baseline visits as an appointment status labeled as New, with subsequent visits assumed to be corresponding follow-ups. A patient’s true first visit to BHA could have been earlier than defined. We acknowledge the challenges with generalizability of our results due to the racial/ethnic and economic (e.g. insurance status) composition of our patient population. While our methodological approach satisfies an evaluation of short-term depression outcomes based on often-used clinical cutoffs, we know that many patients continue in BHA after the six-month mark and that evaluation of their longer-term symptom trajectories could offer valuable insight to patterns of symptoms over time. Future work will explore this topic.