Is Future Mental Imagery Associated with Reduced Impact of the COVID-19 Pandemic on Negative Affect and Anhedonic Symptoms in Young People?

Depression is common in adolescents and young people (Zhou et al., 2020), with 2.7% of 11–16 year olds and 4.8% of 17–19 year olds, in the UK (Mental Health of Children & Young People in England, 2017 [PAS], 2018) and 1.1% of 10–14 year olds and 2.8% of 15–19 year olds, globally (World Health Organization [WHO], 2021), experiencing an episode of major depressive disorder. Youth depression is associated with disruptions to education, socialising and increased risk of developing long-term physical and/or mental health problems (Maughan et al., 2013; Thapar et al., 2012). Yet, current treatments for adolescent depression are suboptimal (Lewandowski et al., 2013). One explanation is that frontline psychological interventions primarily use verbal techniques focussed on the present moment (“here and now”) (Westbrook et al., 2007). Disruptions in prospective mental imagery plays a key role in adolescent depression, yet it is commonly neglected in current interventions (Pile et al., 2021). A second limitation of current treatments is that they tend to focus solely on alleviating negative mood rather than enhancing positive affect, despite adolescent depression involving anhedonic symptoms (Clark & Watson, 1991; Craske et al., 2016; Dunn, 2012). Improving our understanding of key cognitive factors that might be differentially associated with positive vs negative affect could enable more precise matching of specific difficulties to treatment techniques, enhancing current treatments. Here, we investigated: (a) the concurrent relationships between the vividness of positive and negative prospective mental imagery and positive and negative affect, and (b) whether these aspects of future imagery moderated the impact of stress—those posed by the uncertainty and lockdown restrictions of the coronavirus pandemic (COVID-19)—on negative and positive affect. In our large sample of 2602 young people, we also confirmed the factor structure of the Prospective Imagery Task (PIT) and explored the effects of demographic variables (age, sex and ethnicity on aspects of future imagery).

Mental imagery is described as representations of sensory information without external input (Pearson et al., 2015). Unhelpful emotional mental imagery (including frequent, vivid and distressing images of past events and those of future goals) may play a key role in the development and maintenance of mood disorders. To date, most research has focussed on distressing (negative) imagery of past events, with between 44 and 87% of depressed adults reporting frequent vivid, distressing, and unwanted memories of significant life events which are associated with negative emotions, including dysphoria concurrently (Birrer et al., 2007; Brewin et al., 1996, 2009; Kuyken & Brewin, 1994; Patel et al., 2007), and prospectively, even after controlling for early symptoms (Brewin et al., 1999). Distressing and intrusive images of the past may also maintain depressive mood in young people (Kuyken & Howell, 2006; Meiser-Stedman et al., 2012). Negative memories are more vivid in depressed adolescents than those who have never been depressed (Kuyken & Howell, 2006) and increased frequency of intrusive images, which may relate to vivid negative memories, are linked with higher symptoms of depression in adolescents (Meiser-Stedman et al., 2012). Targeting these distressing images in treatments—for example, through imagery rescripting—can reduce depression (and anxiety) in adults (Brewin et al., 2009; Wheatley et al., 2007) and adolescents (Pile et al., 2021).

A more recent line of research has focussed on biases in future mental imagery (Roepke & Seligman, 2016). Whereas studies of mental imagery of past events focus mainly on negative images, future mental imagery, which underlies the ability to make predictions about the future, has been studied in relation to the forming of specific and detailed plans around positive outcomes e.g., goals (Boland et al., 2018; Szpunar et al., 2014). The ability to vividly imagine a goal-related future event may help individuals plan actions and anticipate potential barriers to work towards their desired goal (Taylor & Schneider, 1989). If depressed individuals have difficulty simulating vivid images of specific events and instead, generate more general future expectancies (Anderson et al., 2016), then they will also predict future goals as less likely to occur and being less controllable (Dickson et al., 2011), which in turn may drive feelings of hopelessness about the future (Beck, 1979; Rubenstein et al., 2016b). Consistent with this, research in adults has consistently shown that depression (rather than anxiety) is associated with impoverished future mental images of positive events (Anderson & Evans, 2015; Holmes et al., 2008b; MacLeod & Byrne, 1996; Morina et al., 2011). Within this body of work, experimental studies show that imagining positive events has a specific impact on positive affect over time in healthy and dysphoric individuals (Holmes et al., 2008a, 2008b). These effects are thought to translate into actual goal attainment, as generating positive imagery increases the vividness of positive images (Boland et al., 2018; Pictet et al., 2011) and the perception that these events are more important, controllable, and likely to occur in dysphoric individuals (Boland et al., 2018). In depressed individuals, positive future images also shape more behavioural activation (Renner et al., 2017).

Far fewer studies have explored the association between positive images of the future and the absence of positive affect in young people, despite the importance of these findings for treatment models of anhedonic symptoms, which could bridge the gap in efficacy of current treatments. To date, only one study to our knowledge has measured prospective mental imagery in relation to depression (and anxiety) symptoms in young people (Pile & Lau, 2018). This found that adolescents with high depression (rather than anxiety) scores were associated with less detailed, vivid images of future positive events. In contrast, both anxiety and depression symptoms associated with more detailed and vivid images of past and future negative events. Thus, the absence of positive affect that uniquely characterises depression associates with deficits in future positive imagery while negative affect that characterises depression and anxiety associates with deficits in future negative images, but these specific associations need validation.

This study advances existing knowledge by exploring associations between positive and negative prospective images with negative affect and the absence of positive affect (anhedonia) in a large sample of adolescents and young adults across a broad age range (12–25 years). We aimed to test the primary hypotheses that reduced vividness of positive future images would be associated with increased symptoms of anhedonia in young people while elevated vividness of negative future images would be associated with increased negative affect. As past studies have found that cognitive factors, such as attributional style can moderate the impact of negative life events on symptoms of depression in adults (Rubenstein et al., 2016a), adolescents (Joiner & Wagner, 1995; Lakdawalla et al., 2007), and children (Vines & Nixon, 2009), we also aimed to assess whether future imagery variables moderated the effects of stress on symptoms of depression. A previous study showed that vividness of positive imagery moderated the relationship between the severity of negative life events and symptoms of depression in adolescents (Pile & Lau, 2018) and here we extended that finding to distinct symptoms of depression (negative affect, anhedonia). We tested these predictions on anhedonia and negative affect that emerged during the COVID-19 pandemic, measuring individual differences in self-reported stress. The COVID-19 pandemic has been a period of high disruption to the lives of young people globally, through school closures, social isolation, and quarantine (Brookes et al., 2020; Lee, 2020; Loades et al., 2020) and symptoms of depression have significantly increased from before to during the pandemic in adolescents aged between 9 and 18 years in the USA, Netherlands, Peru, and Australia (Barendse et al., 2022; Magson et al., 2021). Finally, whilst the Prospective Imagery Task (PIT) has been adapted for use in young people, previous studies have not had large enough samples to explore its factor structure. Therefore, we also aimed to explore the factor structure of the PIT in young people, as well as the effects of demographic factors (age, sex, ethnicity minority status and parental educational levels) on mental imagery variables. Understanding the cognitive mechanisms of positive and negative future imagery in relation to anhedonia and negative affect may provide useful insights for treatment of adolescent depression.

Table 1 shows the means and standard deviations for negative affect, anhedonia, positive and negative future imagery, and the impact of COVID-19 variables for the whole sample and by sex.

Whilst theoretical frameworks such as the Tripartite Model (Clarke & Watson, 1991) have identified shared and unique cognitive correlates between anxiety and depression—findings that appear to characterise adolescents (Pile & Lau, 2018)—our findings spoke to distinct links between future imagery variables and distinct dimensions of depression (negative affect and anhedonia). Our findings went further by suggesting that positive and negative future imagery also had differential moderating effects on the relationship between the impact of COVID-19 and negative affect and anhedonia. Those with more vivid negative future images showed a stronger association between COVID-19-related stress and negative affect. In contrast, those with more vivid positive future imagery had weaker associations between COVID-19-related stress and anhedonia. These findings broadly support results by Pile and Lau (2018) which found that elevated vivid positive future imagery protected against the effects of life events on symptoms of depression in adolescents. A potential mechanism by which positive future mental imagery may reduce depressive symptoms particularly anhedonia is through its associations with optimism, psychological wellbeing and resilience to stress (Blackwell et al., 2013; Ji et al., 2017). Although these findings are intriguing, the cross-sectional nature of both our data and the data reported by Pile and Lau (2018) limits our ability to tease out whether these cognitive factors precede or follow symptoms of depression. Individuals with increased negative future imagery and reduced positive future imagery may be vulnerable to experiencing depression, but it is equally possible that depression symptoms impact the ability to generate vivid images.

We also gathered data to support the 2-factor structure of the Prospective Imagery Task and used this measure to explore the effects of demographic factors on positive and negative future images. Previous research has shown the importance of memory in our ability to imagine future events (Byrne et al., 2007; Schacter et al., 2007), and as adolescence represents a period when autobiographical memory develops (Fivush et al., 2011), we explored whether age is related to vividness of positive and negative future images. Positive future images were more vivid in younger adolescents than “emerging adults”, but there were no age differences for negative future imagery. Gulyás et al. (2022) recently found that vividness of mental imagery declines as a function of biological age, and here, we found that this was true for positive future imagery only. Our results suggest that promoting positive future mental imagery may be important in those approaching young adulthood—which is also a juncture associated with transitions—to further education or employment. While previous research in young people and adults shows that females have more vivid mental images than males (Campos & Sueiro, 1993; Gulyás et al., 2022; Isaac & Marks, 1994), we found that these differences depend on the valence of the images. Females reported less vivid imagery for positive future events and more vivid imagery for negative future events than males. Finally, our data revealed some small but potentially interesting differences across minority and majority ethnic and socioeconomic groups that may require further exploration. White participants had reduced vividness of positive future imagery compared to minority ethnic group participants, but there were no differences between these groups for vividness of negative future imagery. In terms of SES, participants whose parents did not have a degree (i.e., lower SES) had reduced vividness of both positive and negative future imagery, compared to participants whose parents did have a degree (higher SES).

Our findings are limited by the cross-sectional design of data collection but also by the use of a non-clinical sample without clinical measures of depression. However, putting these in the context of existing findings, could reveal some interesting implications for the treatment of adolescent depression. First, targeting negative future imagery could be important for the treatment of adolescent depression. In comparison to verbal techniques, prospective mental imagery has received less attention in depression, despite intrusive and distressing memories being common in depression (Wheatley & Hackmann, 2011). Imagery re-scripting, which involves patients focusing on the content of their intrusive images/memories and vividly imagining alternative, more positive outcomes (Hackmann, 1998), has shown promising results in reducing distress associated with memories in depressed adults (Brewin et al., 2009). A recent randomised controlled trial in adolescents found that compared to a control group, receiving nondirective supportive therapy, young people who received an imagery-based cognitive behavioural intervention involving memory specificity training and imagery rescripting had reduced symptoms of depression, greater memory specificity and greater abilities at imagining future events (Pile et al., 2021). Imagery re-scripting for future feared situations has recently been used to facilitate behavioural experiments in social anxiety and has been shown to reduce levels of anxiety and reduce the predicted probability and severity of the feared outcome (Landkroon et al., 2022). As our results, at least cross-sectionally, indicate that elevated negative future imagery and reduced positive future imagery are associated with negative affect, re-scripting negative future images for more alternative, positive future images could be a potential mechanism to treat adolescent depression, whereby distress and predicted probability for negative future events may be reduced, though this would need to be explicitly tested.

Second, current psychological interventions do not adequately address anhedonia or bolster positive affect, which may lower overall efficacy of treatments in all young people, or particularly in those with anhedonic symptoms. In adults, psychological interventions using positive future mental imagery have been used to target symptoms of depression with promising results. These interventions involve Episodic Future Thinking (EFT) Activities and Positive Imagery Cognitive Bias Modification (CBM). EFT activities aim to enhance detail and vividness of images for all future events but particularly positive events, by increasing anticipatory pleasure (Hallford et al., 2020). As anticipatory pleasure is associated with motivation (Engel et al., 2013) and psycho-social functioning (Foussias et al., 2011), enhancing positive affect when anticipating positive future events may be a promising mechanism to reduce anhedonia (Schubert et al., 2020). Positive imagery CBM targets mental imagery and interpretation by repeated practice of generating positive mental imagery resolutions to ambiguous training stimuli, to create more positive imagery biases to allow individuals to automatically imagine positive resolutions to novel everyday ambiguous information (Blackwell et al., 2015; Holmes et al., 2016). Depressed individuals who received positive imagery CBM showed significantly reduced symptoms of anhedonia compared to controls (Blackwell et al., 2015) and increased positive affect (Holmes et al., 2016), but not other symptoms of depression (Blackwell et al., 2015). Whilst these results are in adult populations, Burnett-Heyes et al. (2017) found that generating positive images increased positive affect and reduced negative interpretation bias in healthy adolescents.

Other than the cross-sectional design and use of a non-clinical sample, there are some additional limitations of the current study. First, the PIT replies on self-report, making it difficult to assess how accurate vividness ratings are. Moreover, when administering the PIT, we did not prompt for content, emotional intensity, or likelihood of the images. Vividness ratings could therefore be further confounded by differences in the likelihood of events and the emotional intensity of the events particularly where the items referred to more general categories of events. Additionally, it is possible that life events related to events on the PIT may have influenced vividness ratings, e.g. “You will be unwell” may be more vivid to a young person during the COVID-19 pandemic. Future studies using the PIT in young people should consider rating the emotional intensity of the images generated and the likelihood of each event. A final caveat around only using the PIT in this study is that the data cannot shed light on whether future thinking more generally is affected in those with high negative affect and anhedonia—or if it is prospective imagery specifically which correlates with affective disturbances. The addition of non-imagery-based measures of prospective cognition could identify unique and complementary effects of these aspects of future thinking. Second, we collected data during the COVID-19 pandemic. While this enabled us to assess the degree to which imagery variables may moderate the effects of stress on depression symptoms, it is difficult to know whether these will generalise to daily stressors and challenges beyond the pandemic. Third, a minority of our sample (n = 42) resided in countries outside of the UK. We assumed that most participants were comfortable with reading English (and therefore understanding questionnaire items) because the study was promoted and disseminated through UK-based educational institutions, charities and social media accounts. Nonetheless, as we did not formally assess reading comprehension, this may have affected the validity of questionnaire scores.

In closing, our results indicate that in adolescence, symptoms of negative affect are associated with having more vivid negative future imagery and less vivid positive future imagery, whereas symptoms of anhedonia are only associated with having reduced vividness of positive future imagery. Vividness of negative future imagery moderated the relationship between the impact of COVID-19 and negative affect, and vividness of positive future imagery moderated the relationship between the impact of COVID-19 and anhedonia, but not vice-versa. These findings build on previous literature exploring the role of prospective imagery in adolescent depression. With further replications in longitudinal designs and in clinical samples, they could inform novel mechanisms to improve psychological treatments for young people with depression.