A new study published in the Journal of Affective Disorders used a network modeling approach to explore how cognitive processes like flexibility and processing speed are connected to depressive symptoms. The researchers found that these cognitive traits do not influence depression symptoms directly but through their effects on how individuals regulate emotions—particularly through patterns such as rumination.
Major depressive disorder is one of the most widespread mental health conditions, yet its treatment continues to face challenges related to recurrence and treatment resistance. While cognitive models of depression have long proposed that emotion regulation strategies and cognitive impairments play key roles in maintaining the disorder, these models often treat these components in isolation. In reality, individuals tend to use multiple emotion regulation strategies simultaneously, and cognitive abilities like processing speed and flexibility may influence how people manage emotions in complex ways.
The researchers aimed to move beyond simplified models and instead capture the interactions between emotion regulation strategies, cognitive processes, and depression. They used a network analysis approach, which treats each element as a “node” in a system and models how these nodes influence one another. This method offers a more realistic representation of how depression develops and persists by focusing on the interconnectivity of psychological components.
Daniel Castro, an assistant professor at the University of Maia, explained that his interest in this topic stems from two main motivations. “First, my interest in the capabilities of explanation of psychological phenomena from a network perspective, which differs from traditional approaches that impose a medical perspective on psychological phenomena—one that is distant from the clinical perspective used to explain them. Second, the interest in understanding, from this perspective, what insights into depression development might be obtained when studying the interaction between cognitive processes, cognitive emotion regulation strategies, and depression.”
The researchers analyzed data from 227 healthy participants from the Leipzig Study for Mind-Body-Emotion Interactions, which included both young adults (ages 20–35) and older adults (ages 59–77). For this study, the researchers focused on two cognitive processes: processing speed and cognitive flexibility. Processing speed refers to how quickly a person can take in, understand, and respond to information, while cognitive flexibility is the ability to shift between different thoughts, tasks, or perspectives as needed. These were assessed using the Trail Making Test, a neuropsychological tool where participants connect a series of numbers and letters under time constraints. Shorter completion times indicated better performance.
Depression symptoms were measured using the Hamilton Depression Rating Scale, although participants in this sample were not clinically depressed. Emotion regulation strategies were evaluated with the Cognitive Emotional Regulation Questionnaire, which includes subscales such as rumination, positive reappraisal, self-blame, and catastrophizing.
Rumination involves repeatedly thinking about distressing experiences or negative emotions, often without reaching a resolution, which can intensify feelings of sadness or hopelessness. Positive reappraisal is a strategy where individuals try to reinterpret a negative situation in a more positive or meaningful way, helping to reduce emotional distress. Self-blame occurs when people attribute negative events to their own character or actions, often leading to guilt or shame. Catastrophizing is the tendency to assume the worst possible outcome in a situation, which can increase anxiety and feelings of helplessness.
The team used a network modeling method known as Mixed Graphical Models to estimate the structure of interactions between cognitive processes, emotion regulation strategies, and depression. They then evaluated each node’s influence in the network and simulated how changes in processing speed and cognitive flexibility might impact the network as a whole.
Surprisingly, neither processing speed nor cognitive flexibility had a direct link to depression symptoms. Instead, their influence was mediated through cognitive emotion regulation strategies—especially rumination. This suggests that while these cognitive abilities are important, they may shape mental health outcomes indirectly by altering how people regulate their emotions.
The findings indicate that “emotion regulation strategies directly influence depression and that difficulties in cognitive processes influence emotion regulation strategies,” Castro told PsyPost. “This suggests that cognitive processes might promote difficulties in emotion regulation, which might then impact depression.”
Within the network, rumination emerged as a central node with the highest influence. It also served as the shortest path between the cognitive processes and depression, highlighting its pivotal role. Catastrophizing and positive reappraisal were also highly central in the network, reinforcing the idea that emotion regulation strategies are at the heart of depressive experiences.
When it came to the cognitive processes, the two played different roles. Processing speed showed high “bridge centrality,” meaning it served as a connector between different parts of the network. This suggests that improving processing speed might be effective for preventing depression by weakening harmful connections or preventing them from forming. However, its effect on reducing overall symptom activity was modest.
Cognitive flexibility, on the other hand, had a more substantial effect on the overall network. Simulations showed that higher cognitive flexibility reduced overall network connectivity—a finding consistent with the idea that lower connectivity is associated with fewer depressive symptoms. This implies that training aimed at improving cognitive flexibility might be more effective in symptom reduction than efforts focused on processing speed alone.
“From the two cognitive processes studied, only processing speed was related to emotion regulation strategies, even though cognitive flexibility had a bigger impact on the network connectivity,” Castro said. “Since network connectivity has been suggested to identify psychopathological states, difficulties in cognitive flexibility might promote the development of psychopathological disorders, but the impact on depression only happens through processing speed and emotion regulation strategies.”
The researchers also ran simulations where they set the cognitive processes to their highest or lowest observed values and measured changes in the network’s overall activity. When both processing speed and flexibility were high, network activity decreased, suggesting a healthier mental state. When both were low, network activity increased, indicating more vulnerability to depressive symptoms. The simulations reinforced the idea that these cognitive processes interact with emotion regulation strategies in complex ways that cannot be captured by simpler models.
As with all research, the study comes with limitations. The sample consisted of healthy individuals, which may limit how well the findings apply to people with clinical depression. Since the depression score was based on a single overall rating rather than individual symptoms like fatigue or anhedonia, the model may have missed important connections. Future studies should include more detailed assessments to better capture the full picture.
Another limitation lies in the tools used to measure cognitive flexibility and processing speed. The Trail Making Test is a common assessment tool, but its two parts (A and B) are highly correlated and may not fully isolate the constructs of interest. More refined tools or additional measures could help separate their individual contributions in future research.
The cross-sectional nature of the study also prevents any firm conclusions about causality. While network analysis and simulations can suggest which components are likely to be influential, longitudinal or experimental studies are needed to confirm whether changing these factors would actually alter depression risk or symptom severity.
The authors suggest that future work should aim to validate the tools used to measure cognitive constructs more clearly. In parallel, there is a need for new theoretical models and methods within network psychology that can accommodate diverse types of data, including behavioral, emotional, and biological measures. In the long run, the goal is to develop more personalized interventions by understanding which components in the mental health network are most amenable to change.
“I think that there are two important steps,” Castro explained. “For the continued study of cognitive processes, we need clarification of task validity to assess specific constructs. From a network perspective, there is a need for new theoretical and methodological developments. The need for large sample sizes and the lack of instruments that are constructed and validated from a network perspective limits our ability to extract clear results from these studies. The emergence of the utilization of passive data in the study of psychological phenomena might be important to overcome these limitations.”
The study, The differential impact of processing speed and cognitive flexibility on cognitive emotion regulation strategies and depression, was authored by Daniel Castro, Pedro Lopes, Ana Sofia Araújo, Filipa Ferreira, Ana Rita Rodrigues, Joana Cardoso, Fernando Ferreira-Santos, and Tiago Bento Ferreira.