A recent study published in Psychological Medicine has uncovered new insights into how specific symptoms of depression influence the effort people are willing to put into various tasks. The research offers a detailed examination of how symptoms such as anxiety, anhedonia (loss of interest or pleasure), and apathy affect an individual’s decision-making process when it comes to balancing effort and reward. The study, led by Laura Ana Bustamante, a neuroscientist and postdoctoral fellow at Washington University in St. Louis, explores a crucial and often overlooked aspect of depression: its effects on cognitive and physical effort.
The Importance of Effort in Depression
Effort-based decision-making involves weighing the potential rewards of completing a task against the amount of work required. For people with depression, this calculus is often distorted, making goal-directed behavior, which typically involves planning, motivation, and sustained effort, more challenging. Depression is associated with a range of debilitating symptoms, including low energy, cognitive difficulties, and emotional numbness, which may impair an individual’s ability to invest mental or physical effort in daily tasks.
Bustamante’s study set out to understand how the symptoms of depression influence decisions regarding the amount of effort individuals are willing to exert. She and her colleagues tested their hypothesis by exploring whether certain depressive symptoms are linked to different levels of effort-based decision-making.
As Bustamante reflects, her personal experiences as a neurodivergent individual with fluctuating cognitive states during periods of low mood fueled her desire to understand why cognitive functioning changes during depression. “I was in the perfect position to test this account,” she explains, citing her work at the Princeton Neuroscience Institute where she developed a task to measure a person’s willingness to exert cognitive and physical effort.
Methodology: The Effort Foraging Task
The study involved 97 participants, 67 of whom had been diagnosed with major depressive disorder (MDD), while the remaining 30 participants were healthy individuals with no psychiatric diagnosis. Participants were tasked with completing the Effort Foraging Task, designed to simulate real-life decisions regarding the trade-off between effort and reward.
In this task, participants “harvested rewards” from virtual patches, each with diminishing returns. At any given point, they had the option to either continue gathering rewards from the patch or leave for a new one. Leaving the current patch involved some cost in terms of both time and physical or cognitive effort. The difficulty was adjusted across conditions; for example, cognitive effort required participants to complete a challenging working memory task, while physical effort meant pressing keys repeatedly.
By analyzing the data from participants’ choices of when to move to a new patch, researchers could evaluate their thresholds for quitting and perceive their tolerance for both cognitive and physical effort. Additionally, Bustamante used computational models to analyze these decisions, giving a richer understanding of participants’ motivational levels and perceived opportunity costs.
Key Findings: Anxiety Increases Cognitive Effort
One of the most surprising findings from the study was the relationship between anxiety symptoms and a higher willingness to exert cognitive effort. Contrary to the common belief that depression universally leads to a decrease in cognitive motivation, this study found that individuals with higher levels of anxiety symptoms were actually more willing to engage in effortful cognitive tasks.
Bustamante postulated that this effect might occur because anxiety, a common component of depression, could act as a compensatory mechanism. In other words, individuals who experienced heightened anxiety might engage their cognitive resources more vigorously, perhaps as a way of reducing worry or attempting to control their thoughts. This result contrasts with traditional views that depict depression as solely involving a lack of motivation and cognitive sluggishness.
“Our analyses allowed us to see that anxiety symptom severity was selectively related to increased willingness to exert effort,” Bustamante said. This finding has not been previously reported and provides a new perspective on anxiety as potentially stimulating cognitive engagement in people with depression. She also notes that the effort expended to manage distressing thoughts could possibly offer a productive distraction and prevent spiraling negative thinking.
Anhedonia and Apathy Lead to Physical Effort Avoidance
While anxiety was associated with increased cognitive engagement, the same study found that anhedonia (a core symptom of depression, often characterized by a loss of pleasure or interest in previously rewarding activities) and behavioral apathy were linked to an increased avoidance of physical effort. This outcome makes sense, as physical effort is often harder for individuals dealing with symptoms like fatigue, low energy, and emotional disconnection. The study shows that these emotional and physical barriers might reduce a person’s capacity or willingness to engage in demanding physical tasks.
Anhedonia, in particular, plays a key role in shaping an individual’s perception of rewards. When people experience a diminished ability to derive pleasure from outcomes, they are less likely to engage in activities, even if they might normally find them rewarding. This difficulty can become self-reinforcing, as it discourages future engagement and contributes to a growing sense of disinterest in life’s activities, exacerbating the depressive state.
Severity of Depression and Perception of Time
One particularly striking observation from the study was that individuals with more severe depression appeared to make different decisions when it came to time management. Participants experiencing higher levels of depression severity demonstrated a tendency to leave tasks earlier, suggesting they perceived time as less valuable or less relevant.
This observation underscores an important psychological feature of depression—the distorted perception of rewards and time. People with depression often feel as though efforts do not yield meaningful results, and their sense of time might feel fragmented or diminished. The decreased interest in prolonging tasks or pursuing potential rewards suggests a profound disconnect from future possibilities.
Symptoms and Decision-Making: Beyond Diagnostic Labels
The study found that the overall severity of depression did not directly affect the willingness to exert effort across the board. Instead, individual symptoms—specifically anxiety, anhedonia, and apathy—were more predictive of effort-related behavior than the general diagnosis of depression itself. This insight challenges conventional thinking in psychiatric research, where much attention is often placed on categorical diagnostic labels rather than specific symptom clusters.
Given these findings, Bustamante emphasizes the importance of considering these individual symptom profiles when researching depression and related mental health conditions. Mental health diagnoses should take into account a broader array of symptomatology, as this personalized approach may better capture the nuanced effects of the disorder and lead to more tailored treatment strategies.
Study Limitations and Future Directions
Despite these compelling findings, it is important to note that the study has certain limitations. The cross-sectional design prevents researchers from making definitive conclusions about causality, meaning they cannot claim that depression symptoms directly cause individuals to change their behavior in terms of effort-based decisions. Additionally, the study’s laboratory-based design used specific manipulations that may not entirely mirror real-world situations. Different tasks and external variables could lead to different patterns of decision-making in natural settings.
Future studies, Bustamante suggests, should aim to explore the causal nature of the relationships identified in this research. Longitudinal or experimental studies may offer more insight into whether, for example, modifying how individuals deal with their anxiety could enhance their willingness to engage in cognitive tasks.
The Broader Impact of the Study
Bustamante’s research offers a potential pathway for clinical interventions that recognize depression’s complex effects on cognitive and physical effort. The findings contribute to the emerging field of computational psychiatry, a discipline that uses mathematical and computational models to better understand the inner workings of mental health disorders and how symptoms impact behavior.
By exploring how anxiety can be seen as an adaptive mechanism to motivate cognitive effort, as well as how apathy and anhedonia can reduce physical effort, Bustamante hopes to uncover more dynamic solutions to addressing depression. Understanding the interplay between cognitive function, emotional states, and effort may eventually help guide treatments that are more focused on individual symptomatology, playing to an individual’s strengths rather than just managing deficits.
As Bustamante puts it, “Understanding the dynamic interplay between affect, anxiety, effort, and cognitive function will put us in a better position to find effective solutions.” She has strong faith in integrating perspectives from neurodivergence and disability advocacy into the conversation, believing that recognizing how environmental factors shape decision-making may one day improve the design of therapeutic approaches and behavioral interventions.
Conclusion: Insights into Depressive Decision-Making
Bustamante’s study provides crucial insights into how different depressive symptoms contribute to decision-making processes. Rather than oversimplifying depression as a disorder of global motivation loss, the study highlights the subtleties that exist within its symptom clusters. Anxiety, as shown in this study, can paradoxically lead to greater cognitive engagement, while anhedonia and apathy impede physical effort, further complicating treatment strategies.
As our understanding deepens of how depression alters our ability to assess rewards and effort, clinical researchers and mental health professionals can potentially offer more effective, individualized approaches to treating and supporting individuals suffering from this devastating illness.