Essential considerations when choosing a modern antidepressant

Characterizing depression after traumatic brain injury using a symptom-oriented approach

BACKGROUND

Progress in addressing depression after traumatic brain injury (TBI) has been limited. Traditional approaches to measuring depression classify individuals with diverse symptoms as having the same problem. We adopted a novel, symptom-oriented approach to characterize post-TBI depression, emphasizing specific symptoms rather than the number of symptoms.

METHODS

We assessed depressive symptoms cross-sectionally in 393 participants with moderate-severe TBI (range 0.4-35.4 years post-injury; M = 12.6) using the Inventory of Depression and Anxiety Symptoms - Expanded Version (IDAS-II). We analyzed symptoms of DSM-5 major depressive disorder (MDD), separating compound symptoms into sub-symptoms. We quantified depression heterogeneity across 16 specific symptoms and explored associations between each symptom and personal, injury-related, treatment, and functional/psychosocial outcome factors.

RESULTS

28 % of participants self-reported a current depression diagnosis, and 35 % met DSM-5 symptom criteria for MDD. Depressed participants (according to either self-reported diagnosis or MDD symptom criteria) were more likely to endorse each specific depressive symptom, including those that overlap with TBI. Post-TBI depression was highly heterogeneous, with 84-91 % of depressed participants (depending on classification method) showing a unique symptom profile not shared with any other individual. The most common symptom profile was shared by only three individuals. This heterogeneity was meaningful, as specific depressive symptoms had distinct associations with personal, injury-related, treatment, and outcome factors.

LIMITATIONS

Cross-sectional design. We only analyzed DSM-5 MDD symptoms, and some symptoms were assessed using only one item.

CONCLUSIONS

A symptom-oriented approach to post-TBI depression captures the individual's unique profile of depressive symptoms, which relate differently to outcomes and other factors. We recommend future studies investigating post-TBI depression analyze specific symptoms alongside overall depression scores.

Maintaining Outcomes of Internet-Delivered Cognitive-Behavioral Therapy for Depression: A Network Analysis of Follow-Up Effects

Background: Depression is a highly prevalent mental disorder, but only a fraction of those affected receive evidence-based treatments. Recently, Internet-based interventions were introduced as an efficacious and cost-effective approach. However, even though depression is a heterogenous construct, effects of treatments have mostly been determined using aggregated symptom scores. This carries the risk of concealing important effects and working mechanisms of those treatments. Methods: In this study, we analyze outcome and long-term follow-up data from the EVIDENT study, a large (N = 1,013) randomized-controlled trial comparing an Internet intervention for depression (Deprexis) with care as usual. We use Network Intervention Analysis to examine the symptom-specific effects of the intervention. Using data from intermediary and long-term assessments that have been conducted over 36 months, we intend to reveal how the treatment effects unfold sequentially and are maintained. Results: Item-level analysis showed that scale-level effects can be explained by small item-level effects on most depressive symptoms at all points of assessment. Higher scores on these items at baseline predicted overall symptom reduction throughout the whole assessment period. Network intervention analysis offered insights into potential working mechanisms: while deprexis directly affected certain symptoms of depression (e.g., worthlessness and fatigue) and certain aspects of the quality of life (e.g., overall impairment through emotional problems), other domains were affected indirectly (e.g., depressed mood and concentration as well as activity level). The configuration of direct and indirect effects replicates previous findings from another study examining the same intervention. Conclusions: Internet interventions for depression are not only effective in the short term, but also exert long-term effects. Their effects are likely to affect only a small subset of problems. Patients reporting these problems are likely to benefit more from the intervention. Future studies on online interventions should examine symptom-specific effects as they potentially reveal the potential of treatment tailoring. Clinical Trial Registration: ClinicalTrials.gov, Identifier: NCT02178631.

Neuroticism and chronicity as predictors of 9-year course of individual depressive symptoms

BACKGROUND

The large between-person differences in symptomatology suggest that major depressive disorder (MDD) is a heterogeneous psychiatric disorder. However, symptom-specific prospective studies are scarce. We hypothesized that chronicity (i.e., being depressed for 24 months during a patient's preceding 48 months at baseline) and neuroticism at baseline would predict adverse course trajectories over 9 years of follow up with differential magnitudes for individual depressive symptoms.

METHODS

In total, 560 patients with a current MDD were included from the Netherlands Study of Depression and Anxiety (NESDA-cohort). We used a multivariate linear mixed model with repeated measures, with a history of chronicity and neuroticism separately as main independent variables and with Inventory of Depressive Symptomatology self-report (IDS-SR) item scores as outcome variables. For each individual symptom, the model was adjusted for age, gender, and baseline depression severity.

RESULTS

Patients were on average 42.7 (SD = 12.1) years old and 64.7% were women. Patients with chronic depression or high levels of neuroticism showed similar absolute rates of decline over time compared to their counterparts. However, because symptoms had higher starting points for mood, cognitive, and somatic/vegetative symptoms (in that order), symptom severity remained higher over time. Chronicity and neuroticism were especially linked to persistent low self-esteem and high interpersonal sensitivity.

LIMITATIONS

Neuroticism is partly state dependent and likely affected by depression severity.

CONCLUSIONS

Chronicity and neuroticism predict long-term persistence of diverse psychiatric symptoms, in particular low self-esteem and high interpersonal sensitivity.

Depression sum-scores don't add up: why analyzing specific depression symptoms is essential

Most measures of depression severity are based on the number of reported symptoms, and threshold scores are often used to classify individuals as healthy or depressed. This method--and research results based on it--are valid if depression is a single condition, and all symptoms are equally good severity indicators. Here, we review a host of studies documenting that specific depressive symptoms like sad mood, insomnia, concentration problems, and suicidal ideation are distinct phenomena that differ from each other in important dimensions such as underlying biology, impact on impairment, and risk factors. Furthermore, specific life events predict increases in particular depression symptoms, and there is evidence for direct causal links among symptoms. We suggest that the pervasive use of sum-scores to estimate depression severity has obfuscated crucial insights and contributed to the lack of progress in key research areas such as identifying biomarkers and more efficacious antidepressants. The analysis of individual symptoms and their causal associations offers a way forward. We offer specific suggestions with practical implications for future research.