Comparison of Effect of Antidepressants on Psychomotor Functions

Concussion Symptoms and Neurocognitive Performance of Children and Adolescents on Antidepressants

INTRODUCTION/PURPOSE

There is a well-established association between preexisting depression/anxiety and greater postconcussion symptom burden, but the potential impact of antidepressant medications has not been fully explored. The primary objective of this study was to compare preinjury/baseline and postinjury concussion symptom scores and neurocognitive performance of athletes on antidepressant medications, both with healthy controls and with those with depression/anxiety not on antidepressants.

METHODS

This is a cross-sectional study using data collected from 49,270 junior and high school athletes from computerized neurocognitive assessments (Immediate Post-Concussion Assessment and Cognitive Test [ImPACT]) administered between 2009 and 2018 held by the Massachusetts Concussion Management Coalition. The main outcome measures were symptom scores and neurocognitive performance measures, all of which were assessed both at baseline and postinjury. Statistical analysis included analysis of variance and Tukey pairwise comparisons for continuous variables and Fisher's exact test for categorical variables. Multivariate regression models were used to adjust for potential confounding variables.

RESULTS

Both at baseline and postinjury, athletes with depression/anxiety had mean total symptom scores that were more than double that of healthy controls regardless of antidepressant use. Although there were no significant differences in neurocognitive performance at baseline, depression/anxiety was associated with small but significant decreases in postinjury visual memory and visual motor scores.

CONCLUSIONS

Both at baseline and after sustaining a concussion, young athletes with depression/anxiety experience significantly greater symptom burden compared with healthy controls regardless of antidepressant use.

Non-REM sleep in major depressive disorder

Disturbed sleep is a key symptom in major depressive disorder (MDD). REM sleep alterations are well described in the current literature, but little is known about non-REM sleep alterations. Additionally, sleep disturbances relate to a variety of cognitive symptoms in MDD, but which features of non-REM sleep EEG contribute to this, remains unknown. We comprehensively analyzed non-REM sleep EEG features in two central channels in three independently collected datasets (N = 284 recordings of 216 participants). This exploratory and descriptive study included MDD patients with a broad age range, varying duration and severity of depression, unmedicated or medicated, age- and gender-matched to healthy controls. We explored changes in sleep architecture including sleep stages and cycles, spectral power, sleep spindles, slow waves (SW), and SW-spindle coupling. Next, we analyzed the association of these sleep features with acute measures of depression severity and overnight consolidation of procedural memory. Overall, no major systematic alterations in non-REM sleep architecture were found in patients compared to controls. For the microstructure of non-REM sleep, we observed a higher spindle amplitude in unmedicated patients compared to controls, and after the start of antidepressant medication longer SWs with lower amplitude and a more dispersed SW-spindle coupling. In addition, long-term, but not short-term medication seemed to lower spindle density. Overnight procedural memory consolidation was impaired in medicated patients and associated with lower sleep spindle density. Our results suggest that alterations of non-REM sleep EEG in MDD might be more subtle than previously reported. We discuss these findings in the context of antidepressant medication intake and age.

Depression development: From lifestyle changes to motivational deficits

Until now, depression research has taken a surprisingly narrow approach to modelling the disease, mainly focusing on some form of psychomotor retardation within a mechanistic framework of depression etiology. However, depression has many symptoms and each is associated with a vast number of substrates. Thus, to deepen our insights, this SI ("Depression Symptoms") reviewed the behavioral and neurobiological sequelae of individual symptoms, specifically, psychomotor retardation, sadness, low motivation, fatigue, sleep/circadian disruption, weight/appetite changes, and cognitive affective biases. This manuscript aims to integrate the most central information provided by the individual reviews. As a result, a dynamic model of depression development is proposed, which views depression as a cumulative process, where different symptoms develop at different stages, referred to as early, intermediate, and advanced, that require treatment with different pharmaceutical agents, that is, selective serotonin reuptake inhibitors early on and dopamine-based antidepressants at the advanced stage. Furthermore, the model views hypothalamic disruption as the source of early symptoms and site of early intervention. Longitudinal animal models that are capable of modelling the different stages of depression, including transitions between the stages, may be helpful to uncover novel biomarkers and treatment approaches.

Effect of repetitive transcranial magnetic stimulation (rTMS) treatment of major depressive disorder (MDD) on cognitive control

BACKGROUND

Major Depressive Disorder (MDD) is commonly accompanied by cognitive control dysfunction that may persist after remission of clinical symptoms with antidepressant medication treatment. Repetitive Transcranial Magnetic Stimulation (rTMS) is an effective treatment alternative for medication-resistant MDD. In this study, we investigated whether rTMS treatment had a beneficial effect not only on depressive symptoms, but on also cognitive control dysfunction.

METHODS

77 subjects with MDD received a 30-session treatment course of 10 Hz rTMS administered at the left dorsolateral prefrontal cortex (DLPFC). Treatment efficacy was assessed using the Inventory of Depressive Symptomatology Self-Rated (IDS-SR) before and after treatment, with clinical response defined as 50% or greater decrease in the IDS-SR score at treatment 30. Cognitive control function was assessed before and after treatment using the Stroop word-color interference task. We examined changes in Stroop accuracy and reaction time for congruent and incongruent trials, as well as in relation to changes in depressive symptoms.

RESULTS

Performance accuracy improved particularly for the rTMS responders in the incongruent condition, with older subjects benefitting most from the rTMS treatment. Improvement in reaction times was positively associated with clinical improvement, especially in the incongruent condition.

LIMITATIONS

We used a single cognitive task in a naturalistic setting without control for individual rTMS treatment parameters or concomitant medication.

CONCLUSIONS

Overall, these results indicate that rTMS treatment for MDD has beneficial effects on psychomotor speed and cognitive control. Future studies should extend these findings to larger patient populations and other cognitive domains.