Background

Depression is a leading cause of illness and disability among adolescents worldwide (Word Health Organization, 2021). A diagnosis of Major Depressive Disorder (MDD) places adolescents at an increased risk of suicide (Mullen, 2018), reduced social functioning (Verboom, Sijtsema, Verhulst, Penninx, & Ormel, 2014) and recurrent MDD in adulthood (Rohde, Lewinsohn, Klein, Seeley, & Gau, 2013). A randomized controlled trial (RCT) comparing psychological treatments for adolescents with MDD, the IMPACT study (Goodyer et al., 2017), conducted nested qualitative research (Midgley, Ansaldo, & Target, 2014) to explore adolescents’ experiences of depression (Midgley et al., 2015) and their expectations and experiences of therapy (Midgley et al., 2016). This is important because adolescent presentations of MDD can differ from adults (Roberts, 2013). For example, adolescents with MDD are more likely to present with irritable mood (Powell, Ocean, & Stanick, 2017) and communicate somatic complaints (Bohman, 2012). These differences in presentation and phenomenology may have implications for how depression and treatments for depression are experienced by adolescents.

Fatigue is a somatic symptom of depression which is commonly reported by adolescents with MDD (Nardi, Francesconi, Catena-Dell'osso, & Bellantuono, 2013; Orchard, Pass, Marshall, & Reynolds, 2017). In the IMPACT study cohort of 465 participants, 73.3% of adolescents with a primary diagnosis of MDD experienced significant fatigue (Goodyer et al., 2017). The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition presents the diagnostic features of fatigue in MDD as a decrease in energy, tiredness, a reduced efficacy in tasks which are accomplished and complaints of fatigue without physical exertion (American Psychological Association [APA], 2013). Similarly, the International Statistical Classification of Diseases and Related Health Problem, tenth revision (ICD-10) includes ‘decreased energy or an increased fatiguability’ as one of the core criteria for mild to severe depression (World Health Organization, 1993, pp. 82–83).

Psychological research has conceptualized fatigue as a subjective and debilitating symptom (Fava et al., 2014; Jason, Evans, Brown, & Porter, 2010). Fatigue severity has been associated with increased cognitive and functional impairment, elevated risk of suicide, and increased anxiety in university students with significant depressive symptoms (Nyer et al., 2015). Additionally, ter Wolbeek, van Doornen, Kavelaars, and Heijnen (2008) reported adolescents who were persistently fatigued had more symptoms of depression and anxiety, were less physically active and slept fewer hours than non-fatigued adolescents. Furthermore, fatigue is one of the most common residual symptoms in adults with remitted depression post-treatment (Baldwin & Papakostas, 2006; Conradi, Ormel, & De Jonge, 2011), is a risk factor for depressive chronicity (Moos & Cronkite, 1999) and predicts an inabiliy to achieve remission with treatment (Fava et al., 2014). Thus, fatigue appears to be a prevalent and disabling symptom of MDD, which may place adolescents under an increased risk of adverse outcomes if experienced persistently, or at a significant level.

Both fatigue and depression are complex, heterogeneous constructs. Arnold (2008) highlighted the conceptual similarities between fatigue and depression, noting that physical, affective and cognitive dimensions of fatigue, including decreased activity, low motivation, and reduced concentration and mental endurance are present in other criteria of MDD. These similarities in symptomology can make it difficult to distinguish between fatigue and depressive syndromes (Arnold, 2008). Derived from the medical model, depression is viewed as a distinct illness with defined symptomology (Clark, Cuthbert, Lewis-Fernández, Narrow, & Reed, 2017). Although individuals who are diagnosed with depression may present with shared characteristics, there are many different symptom combinations that meet the diagnostic criteria (Fried & Nesse, 2015). Additionally, each symptom may be experienced in a different way and to a different degree. For example, fatigue as a depressive symptom can be viewed to exist on a continuum, from its absence to a severely impactful presence. This multi-dimensionality of depression means that the structure of classification systems can present challenges in the way we conceptualize MDD.

Even though it is a common symptom in adolescents who are depressed, fatigue may not be thoroughly assessed in Child and Adolescent Mental Health Services (CAMHS) and does not tend to be prioritized, with clinicians often focussing on sleep problems rather than fatigue (Higson-Sweeney, Loades, Hiller, & Read, 2020). This means fatigue may be overlooked in clinical settings, despite how common it is and how debilitating it can be.

Cognitive behavioural therapy (CBT) is a recommended treatment for moderate to severe depression in young people aged 12–18 years (National Institute for Health & Care Excellence [NICE], 2019). CBT is effective in reducing depressive symptoms in adolescents (Keles & Idsoe, 2018; Weersing, Jeffreys, Do, Schwartz, & Bolano, 2017) and in reducing the risk of depression persisting at 17–19 weeks follow up by 63% in adolescents with sub-clinical depressive symptoms (Oud et al., 2019). Furthermore, the IMPACT study provided evidence of CBT’s long-term effectiveness, as reductions in depressive symptoms were maintained at 86 weeks (Goodyer et al., 2017).

CBT is a structured and goal-orientated therapy which focuses on the client’s presenting problem and the processes which are maintaining their difficulties (Kennerley, Kirk, & Westbrook, 2017). In CBT, clients work together with the therapist and are active participants, both within therapy sessions and by applying skills learned in therapy between sessions (Fenn & Byrne, 2013; Tang & Kreindler, 2017). Establishing a collaborative therapeutic relationship and taking an active role in their treatment is an important part of adolescent engagement in CBT (Donnellan, Murray, & Harrison, 2013). The cognitive component of CBT encourages adolescents to identify and challenge their dysfunctional beliefs and negative automatic thoughts, and to consider how to replace negatively biased cognitions with neutral or positive interpretations (Brewin, 2006). The behavioural component of CBT typically focuses on increasing activities that lead to experiences of mastery and pleasure and managing inter-personal relationships through social problem-solving (Kazdin & Weisz, 1998). Adolescents receiving CBT for depression have reported that it helped them by increasing their awareness of how they interpreted situations and by encouraging them to do more pleasurable activities (Bru, Solholm, & Idsoe, 2013).

It is possible that adolescents with MDD who are fatigued could experience the therapeutic process and requirements of CBT as particularly demanding. CBT requires adolescents to attend sessions and actively engage in their treatment by working collaboratively with the therapist and implementing therapeutic techniques (Cully & Teten, 2008). However, the effects of fatigue (e.g., low energy) could negatively impact the experience of CBT. Depressed adolescents have reported fatigue as interfering with engagement in brief behavioural activation (Watson, Harvey, Pass, McCabe, & Reynolds, 2021), so it is possible this could extend to CBT. Exploring how fatigue may affect adolescents’ experience of psychological treatments could highlight ways in which components of therapy could be adapted to meet the needs of these adolescents.

This qualitative study aimed to understand how CBT is experienced by depressed adolescents with clinically significant fatigue. Qualitative research seeks to explore and understand the in-depth meaning and complexities of social contexts and phenomenon (Guest, Namey, & Mitchell, 2013). Thus, it was deemed an appropriate method by which to explore adolescents’ therapeutic experiences.

Methods Setting for the study

A secondary data analysis was conducted using semi-structured interview data from the Improving Mood with Psychoanalytic and Cognitive Therapies: My Experience (IMPACT-ME) study (Midgley et al., 2014). The IMPACT-ME study was a longitudinal qualitative study nested within the IMPACT RCT (Goodyer et al., 2011, 2017). The IMPACT RCT compared the effectiveness and cost-effectiveness of CBT, short-term psychoanalytic psychotherapy and a brief psychosocial intervention in treating MDD in clinically referred adolescents (N = 465; Goodyer et al., 2017). IMPACT-ME conducted interviews with a sub-group of participants (n = 77), who were receiving their assigned treatment from a CAMHS in North London (Midgley et al., 2014). The interviews were conducted at three time points: pre-treatment (baseline), post-treatment (36 weeks) and follow up (86 weeks; Midgley et al., 2014). MDD diagnosis was confirmed at baseline using the Kiddie Schedule for Affective Disorders and Schizophrenia (K-SADS; Kaufman et al., 1997). This study will analyse the post-treatment interview data from the adolescents who took part in the IMPACT-ME sub-study, were allocated to the CBT treatment arm and obtained clinical threshold fatigue on the K-SADS at baseline.

Sample and recruitment

Clinical staff at CAMHS screened patients’ eligibility for the IMPACT study. The inclusion criteria consisted of being aged 11–17 and having a current DSM-IV diagnosis of MDD, with moderate to severe impairment. The exclusion criteria consisted of a primary diagnosis of Schizophrenia, Bipolar I or an eating disorder; having diagnosed learning difficulties or a pervasive developmental disorder; the taking of medication which may disrupt selective serotonin reuptake inhibitors; and an inability to cease taking the medication, substance abuse and pregnancy (Goodyer et al., 2011). On agreeing to participate in the IMPACT study, informed consent was obtained from the adolescent and their primary caregiver (Goodyer et al., 2011).

The transcripts that were analysed in this secondary data analysis were selected from a sample of 41 adolescents, who were randomized to the CBT arm of the IMPACT trial and were interviewed as part of the IMPACT-ME sub-study. The post-treatment interview transcripts of those adolescents who obtained a clinical threshold score of fatigue on the K-SADS at baseline (n = 18) were provided by the Anna Freud Centre for analysis. All identifiable material was removed, and names were replaced with pseudonyms. The sample consisted of female (n = 12) and male (n = 6) adolescents aged 13–18 years (mean = 15.83; Table 1). The adolescents attended a mean number of 10 sessions, with 11 having come to an agreed ending with their therapist. Seven adolescents ended therapy without their therapist's agreement and were considered non-completers. The mean number of sessions attended is comparable to the figures for the overall IMPACT study, as is the proportion who can be considered non-completers (Goodyer et al., 2017). However, previous analysis of data from the IMPACT study has shown that non-completers were themselves a heterogenous group. Although in some cases non-completion was associated with poorer outcomes, that was not always the case (O’Keeffe et al., 2019; O’Keeffe, Martin, Target, & Midgley, 2019). Participants in this sample were recruited from North London, a densely populated area which inhabits approximately four million people. These participants were more ethnically diverse than participants recruited to the trial in other parts of England, which included East Anglia and the North West of England. East Anglia inhabits approximately three million people in its largely rural areas and 100,000 people in four urban areas. North West England is inhabited by approximately four million people, one million of these inhabit rural areas and three million reside in the city of Manchester (Goodyer et al., 2017).

Table 1. Participant characteristics of adolescents assigned to the CBT treatment arm and who scored clinical threshold fatigue on the KSADS at baseline Pseudonym Gender Age Ethnicity Therapy attendance Tia Female 13 White British Non-completer Ella Female 16 White and Black African Non-completer Amira Female 17 Bangladeshi Completer Rachel Female 15 Other Black background Completer Mia Female 16 White British Completer Peyton Female 16 White and Black Caribbean Non-completer Jess Female 17 White British Non-completer Olivia Female 17 Bangladeshi Completer Phoebe Female 14 White British Completer Katie Female 17 Other mixed background Completer Milly Female 15 White British Completer Anya Female 17 Other White background Non-completer Mike Male 18 White British Non-completer Ben Male 14 White British Completer Harry Male 17 Other White background Completer Finn Male 14 White and Asian Non-completer Rob Male 16 White British Completer Taylor Male 16 Other Asian background Completer Data collection

Interviews were conducted by one of a team of trained research assistants and took place at the participant’s home or at the CAMHS clinics, depending on the adolescent’s preference. The post-treatment interview was the ‘Experience of therapy’ interview (Midgley et al., 2011), which explored the adolescents’ experience of therapy, perceived changes and how they understood what had contributed to any of the changes that they described. The participants were encouraged to share their experience in their own words and were reminded that there were no right or wrong answers (Midgley et al., 2016). For further information regarding the interview topic guides see Midgley et al. (2014).

Ethical considerations

This study used secondary data from pre-approved research: The IMPACT study was granted approval from Cambridgeshire Research Ethics Committee (REC Reference: 09/H0308/137; Goodyer et al., 2011). Additionally, the Psychology Research Ethics Committee from the psychology department at the University of Bath approved the proposed secondary data analysis (PREC reference: 20-093).

Data analysis

Framework analysis is a qualitative method which was initially developed for social policy research (Ritchie & Spencer, 1994) and has been used in a variety of research disciplines (Parkinson, Eatough, Holmes, Stapley, & Midgley, 2016; Ward, Furber, Tierney, & Swallow, 2013). Framework analysis sits within the thematic methodology (Gale, Heath, Cameron, Rashid, & Redwood, 2013) and was deemed an appropriate method as it enabled deductive and inductive approaches to analysis. A deductive approach was required when selecting data from the transcripts which related to the adolescents’ experience of therapy. An inductive approach was taken when coding the data, enabling data-driven themes to be developed. Codes were predominantly semantic to capture the participants’ explicit meaning. Latent codes were assigned to data when researcher GH interpreted a deeper underlying meaning.

Data interpretation was underpinned by a constructivist position: adolescents constructed their realities through their subjective therapeutic experiences and GH constructed her knowledge of the adolescents’ experiences through her interpretation of the data (Lincoln & Guba, 2013).

To ensure a reflexive approach to analysis, GH sought feedback from post-graduate student colleagues NH-S, JM and KS and sought input from academic supervisors to refine the themes (ML and EH). GH met with co-authors ML and EH regularly, which promoted reflection. GH, JM and KS were naïve to qualitative research, with experience from academic study. ML, EH and NH-S have qualitative research experience. ML is a clinical psychologist with experience in CAMHS settings and was a CBT therapist in the IMPACT study. GH sought to be cognisant of prior assumptions brought to data analysis by herself and student colleagues by discussing interpretations of the data with colleagues at meetings. The following stages of analysis were conducted as outlined by Gale et al. (2013; Table 2).

Table 2. Stages of framework analysis which were conducted in this secondary data analysis Stage of analysis How the stage was implemented Persons involved in stage of analysis Data Familiarization

Transcripts read and re-read

Fatigue terms ‘tired, energy, worn out, bothered and fatigue(ed)’, were searched, ensuring relevant data were not missed

Relevant sections of transcripts were exported into Microsoft Excel

GH conducted this for all transcripts

KS and JM repeated this separately on two transcripts and GH compared this

Coding

Codes were developed and refined

After receiving feedback, codes that did not accurately reflect the data were amended

GH developed initial codes

KS, JM and GH discussed initial codes via a video meeting

The codes were refined by GH

NH-S reviewed 50% of the coded data

Developing an analytical framework

Refined codes were grouped into categories which represented the coded data

Saturation was deemed to be achieved: no new concepts emerged from the data that were not represented by an existing category (Suter, 2012)

GH developed the analytical framework Applying the analytical framework

Data were indexed by category using the sort and filter tool in Excel

Each category yielded a column of related data and cases related to the category could be identified by row

Feedback ensured the categories encompassed the coded data

GH applied the analytical framework

NH-S reviewed the first five rows of coded data assigned to each category

Charting the data

Data from each category and each participant were summarized

Charting refined data into sizeable chunks and enabled connections and patterns to be identified

GH charted the data Data Interpretation

Connections between categories were identified

Priori concepts or concepts that emerged from the data were explored

Themes were developed using a spreadsheet where illustrative quotes from related categories were allocated by column

GH developed initial themes

GH discussed initial themes with NH-S, JM and KS

Themes were shared with ML and EH for their input

Results

Three themes and seven sub-themes were developed using framework analysis (Figure 1). The themes were created to encompass salient narratives that represented the adolescents’ experience of CBT. Each theme has been described below with illustrative quotes.

Thematic diagram illustrating themes and sub-themes.

Theme 1: The demands and challenges of CBT

This theme encapsulates the difficulties adolescents experienced during therapy. The first sub-theme ‘Competing demands of therapy and fatigue’ explores how the difficulties adolescents experienced appeared to stem from the demands of therapy and fatigue. These difficulties included the ways adolescents struggled to engage in sessions and complete therapeutic homework. The second sub-theme ‘Adjusting to therapy’ encapsulates adolescents’ initial uncertainty and difficulty coping with the emotions evoked during early therapy sessions.

Competing demands of therapy and fatigue Adolescents described various difficulties taking part in their treatment. For some, attending therapy presented challenges which they strived to overcome. Amira (17) described struggling to get out of bed to attend her sessions:

…it was more forcing myself to get out of bed not the actually going part…if it was cold and raining and just you know I felt weak anyway physically…but I still battled through that and went…

Engaging in sessions appeared particularly challenging for adolescents. Anya (17) described therapy as ‘emotionally draining’ and spoke about her difficulty engaging in sessions as she struggled to concentrate:

I couldn’t concentrate…she could tell when my eyes were drifting off… I could listen for literally like 20 minutes at most

For some participants, engaging in sessions appeared stressful ‘I had to like repeat what I was like goin through again and again and again…’ (Tia, 13). ‘I kind of just wanted to be over and done with it so I could relax’ (Ella, 16). At times, adolescents lacked motivation to engage in therapy ‘I didn’t wanna work’ stated Milly (15) ‘if you’re feelin low and you don’t particularly want to talk’.

Difficulties taking part in treatment appeared to extend outside of sessions. Phoebe (14) described the demands of documenting her activity log which appeared to require contemplation and commitment ‘after you did something you kind of have to remember to write it down and then think-thinking over it and then how you felt and then say putting it into a number’.

For others, engaging in therapeutic homework appeared overwhelming. When asked to keep a mood diary in between sessions, Tia (13) described thinking ‘I’m never gonna do this, I just, I’m just wasting this lady’s time and my own time’. Milly (15) described how she struggled to complete therapeutic homework alongside her schoolwork, which appeared to impact subsequent sessions:

It was making me feel worse because he was giving me homework that I didn’t do. And then like when it comes to the homework part of the next session… have you done it? I’ll be like no. Have you got it with you? No…I don’t feel like it helps me in any way.

Adjusting to therapy

Adolescents appeared to find their initial sessions particularly challenging, often communicating uncertainty and apprehension. ‘I just started crying’ explained Ben (14) as he described the worries he experienced. ‘I was sort of worried about what was gunna happen, stressed about what was gunna happen… just wondering what was gunna happen really’.

Adolescents appeared to adjust to the therapeutic dynamics which may have enabled them to emotionally open up. Katie (17) described how initially she was ‘quite closed’ but once she began to confide in her therapist she felt ‘relief was coming off my shoulders’.

However, for some adolescents, describing their difficulties in sessions brought further difficulty. ‘It just kind of felt like it was kind of bringing it all…say to the surface again…’ (Phoebe, 14).

Anya (17) metaphorically described opening up in the initial sessions to creating an ‘open wound’, which she did not have the self-management skills to deal with and was not yet the focus of the sessions:

they're like leaving you… without like help like you know it’s kind of like they're not like helping like stitch the wound up they're just kind of like leaving it open…

However, once the focus of the sessions appeared more proactive, adolescents may have perceived therapy as more helpful.

about… a quarter of the way through…when we kind of stopped talking about everything…and instead thinking of ways to deal with it and cope with it I think that's kind of when I realised that… it was actually… probably gonna help (Phoebe, 14).

Theme 2: Meeting the needs of fatigued adolescents

Fatigued adolescents’ experiences of CBT seemed to largely depend on how well CBT met their specific needs and symptoms. The sub-themes generated reflect three core components of CBT which appeared most impactful. The first sub-theme, ‘The pros and cons of a structured therapy approach’ highlights how in the context of fatigue, the structure of CBT, including how therapeutic goals and activities were experienced could be helpful or a hindrance for adolescents. The second sub-theme, ‘Safety enables engagement’, presents the importance of the therapeutic alliance for engagement, and the consequences for adolescents if there is a lack of rapport. The third sub-theme, ‘Session flexibility’, considers how session frequency and length contributed to difficulties in engagement, and the need for increased flexibility to meet fatigued adolescents’ needs.

The pros and cons of a structured therapy approach

For some, a structured approach to treatment appeared to enable the therapist and adolescent to identify and tackle key issues. Mike (18) expressed having a ‘clear goal’ gave him ‘a sense of ya’know, what I’m doing wiv this, wiv this time’. Olivia (17) also appeared to find the structured session content helpful, which may have made her feel supported in her treatment ‘I like the fact that it had more structure to it…I guess it’s like they were aware of the changes that should happen’.

A structured approach to activity may have helped adolescents combat fatigue symptoms. Amira (17) highlighted the importance of her therapist structuring her activity log at her pace ‘building up the ability and the strength to physically do them and then also the sort of mental stamina to think yeah I'm gonna do this’.

However, there were ways in which CBT’s structured approach did not meet adolescents’ needs ‘there’s already a system laid out for it and you’re just kind of jumping through hoops…like it’s not individual to your situation’ (Mike, 18). Anya (17) felt the structure of therapy was prioritized and lacked collaboration, perhaps to the extent that it hindered her treatment:

‘I don't think she ever cared about me…I think she cared more about the CBT and like keeping to the structure’ as she explained how she felt unable to complete therapeutic tasks ‘I just wasn’t ready to do any of the steps’.

Safety enables engagement

Another way CBT appeared to meet the adolescents’ needs was by providing an environment where they felt listened to and valued ‘it was important that I went somewhere where someone would listen to me and think that I was significant…’ (Olivia, 17).

The relationship with the therapist seemed important for adolescents to engage in therapy. Katie (17) described how her therapist’s non-judgmental stance was particularly helpful:

I started feeling more comfortable…the way that she was talking to me I didn’t feel like she was judging me…

For some, therapy seemed to provide a sense of reassurance regarding their diagnosis. In Amira’s (17) case, the reassurance she received may have helped tackle self-blame:

They sort of reassured me too… this is a REAL thing, that is an illness and some people have it and it’s awful and it isn’t your fault… to hear that was important…

However, others did not feel that therapy provided them with a congenial environment. Ella (16) described the therapeutic environment as ‘too professional’ which may have hindered her engagement, ‘if she made it a bit more comfortable… and a bit more relaxed then maybe I would have felt more comfortable in talking to her’.

Milly (15) described how she felt her therapist was ‘listening, but not listening’. These adolescents appeared to perceive a lack of genuineness in their therapist or the therapeutic environment which did not provide them with a sense of safety and therefore may not have met their needs as clients.

Session flexibility

The ability for sessions to be flexible appeared important to adolescents. ‘I have to go obviously for my well-being but sometimes I wish that the schedule was a bit more flexible’ (Katie, 17). Session length was one component which appeared to impact on their therapeutic experience. Ella (16) described ‘looking at the clock to see when it was over… it was like 50 minutes, it’s quite long’. However, Anya (17), who struggled with her concentration during sessions, explained how she and her therapist shortened her sessions ‘which really helped coz… I felt like, ‘oh thank god!’, it wasn’t too much in one go’.

Session frequency also appeared to be a component which adolescents felt could have been made more flexible. Olivia (17) suggested a longer gap between sessions would have enabled her to implement therapeutic techniques and bring more to sessions ‘I would just have more time to put stuff into action…like there would be more to tell her…’.

Rob (16) explained how a flexible approach was taken to ensure his rest day was not interrupted ‘I should have had a session then but we changed it to be less frequently, so it didn’t interrupt with that [rest] day’.

Theme 3: Change through therapy

This theme consists of two sub-themes. The first sub-theme ‘Evidence of progress, increasing independence and understanding’ encompasses how adolescents appeared to find evidence of their progress in therapy, independence in treatment and gaining an understanding of themselves or others as key components to change. The second sub-theme ‘Noticing and maintaining change’ describes the changes adolescents’ perceived since completing CBT, including how they utilized the skills learned in therapy and whether they experienced changes in fatigue.

Evidence of progress, increasing independence and understanding Adolescents appeared to find being presented with evidence of their progress particularly helpful during therapy. Rachel (15) reflected on her therapeutic homework which provided her with evidence of the behaviours she had implemented, which she seemed to find rewarding:

It’d help to like read it, just like, if somethings bad, I can see, I can do something better, if somethings good, then yeah I could do that again…and like, be proud that I did it in a certain way…

CBT appeared to encourage adolescents to facilitate change independently. Finn (14) described how CBT provided him with ‘a lot of ideas and solutions on like how to help’ which he was able to implement himself. Olivia (17) appeared to find engaging in activities in between sessions provided her with a sense of independence in treatment.

I became sort of more active because like it made sure that there’s an actual link between being… between therapy and the rest of my life… so that's how I could actually make an impact…

Adolescents also appeared to perceive change through therapy by gaining a deeper understanding of themselves and others ‘this whole thing helped me understand other people as well… so, therapy did help in that sense’ (Taylor, 16). While Katie (17) described gaining insight into herself ‘every time I have a session, I feel like I learnt something new about myself’.

Noticing and maintaining change

Adolescents appeared to perceive change through therapy ‘I looked so zombie-like but now it’s like complete transition like within like 6 months’ (Anya, 17). However, others perceived less change, particularly regarding fatigue-related problems ‘I am still always tired’ (Taylor, 16).

Most adolescents expressed that CBT had equipped them with skills to manage their thoughts and feelings.

she’s given me skills like breathing skills, thinking skills…the type of skills to, to cope with it and to understand it so that I can get through it rather than letting it take over my life again (Phoebe, 14).

However, others communicated difficulties maintaining the changes they had made. Rachel (15) described how during therapy she was able to go to the shops again ‘I felt, basically like invincible’, but struggled to maintain her progress ‘it started going back to how it was’.

One self-management method adolescents used was to distract themselves. Harry (17) described how when he began to feel low, he would call a friend or take a shower ‘I'd just be like in another world’. While Finn (14) would ‘listen to music’ when he felt ‘angry or upset’. Similarly, Phoebe (14) expressed a tendency to engage in distraction rather than utilize therapeutic skills:

even though I'd be able to manage them it would just kind of… I wouldn’t really wanna think about it… I just like turn the tv on or get the laptop…so I'm occupied

Discussion

When asked about their experiences of CBT, adolescents with depression who also reported fatigue did not tend to explicitly discuss fatigue, but fatigue appeared to impact their therapeutic experience in nuanced ways. Additionally, the therapeutic process and requirements of CBT appeared challenging. Adolescents described struggling with the emotions that were provoked in early sessions, engaging in ongoing sessions and completing therapeutic homework.

Adolescents found taking part in CBT sessions demanding and some were reluctant or felt unable to discuss their difficulties. Difficulties engaging in therapy are common in adolescents who may not have sought treatment themselves and enter therapy with varying levels of cooperativeness (Bolton Oetzel & Scherer, 2003; Curry & Reinecke, 2003). Participants described struggling to engage in therapy due to their low mood or because they found sessions stressful. Although it is unclear whether engagement was impacted by fatigue, participants who explicitly talked about fatigue in their accounts of how they experienced CBT in this RCT described physical weakness, apathy and poor concentration as reasons for struggling with therapy. Based on these findings, future research exploring whether fatigue is a barrier to therapeutic engagement is warranted. A challenge for this field is the conceptual issues with the construct of depression. For example, poor concentration is listed as a separate symptom of depression to fatigue (APA, 2013), but is experienced, based on our participants’ accounts, as intertwined. Furthermore, apathy may be part of the symptom experience of anhedonia in adolescents who are depressed, and adolescents with anhedonia describe fatigue (Watson, Harvey, McCabe, & Reynolds, 2020). Network analysis has begun to shed light on how symptoms are linked and inter-related. For example, in a community sample of adolescents using the Children’s Depression Inventory, fatigue was most strongly associated with sleep disturbance (Mullarkey, Marchetti, & Beevers, 2019). To further clarify the conceptualization of fatigue as a depressive symptom in diagnosis, the dimensionality of fatigue should be considered in relation to its presence, severity and duration in medical and psychological disorders (Billones, Kumar, & Saligan,