ANXIETY IN ADOLESCENTS WITH CANCER

Being treated for cancer is a major source of stress at any age and, perhaps, particularly for children and adolescents. Children and adolescents with cancer are confronted with the stress of understanding their disease and facing the possibility of dying at a young age. Furthermore, these patients undergo extended treatment plans that are often invasive, painful, and cause significant physical side effects. These treatments are typically very disruptive to patients' lives, leaving children and adolescents with cancer to adjust to shifts in routine and changing relationships with family and peers (Decker, Reference Decker2007).

Children and adolescents with cancer are potentially vulnerable to developing psychosocial difficulties due to the many challenges of cancer and its treatment. To date, anxiety is understudied in this population, despite convincing evidence that anxiety may be a common sequela of pediatric cancer. Kazak and colleagues' research (Reference Kazak, Alderfer and Rourke2004a; Reference Kazak, Alderfer and Streissand2004b; Reference Kazak2005; Reference Kazak, Kassam-Adams and Schneider2006) on posttraumatic stress disorder (PTSD) and posttraumatic stress symptoms has forged a path for research in anxiety among adolescent survivors of pediatric cancer. However, the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM–V; American Psychiatric Association, 2013) recognizes PTSD as unique from other anxiety disorders by including it in a new diagnostic category. This change paves the way for new research involving currently defined anxiety disorders among adolescent survivors of pediatric cancer.

Anxiety has been found to be highly prevalent among cancer patients (Stark & House, Reference Stark and House2000; Stark et al., Reference Stark, Kiely and Smith2002), indicating that the stress of the cancer experience can lead to the development of anxiety symptoms. However, specific research is needed to assess the prevalence and possible manifestations of anxiety in adolescents who have been treated for cancer. Adolescents are in a unique psychosocial phase that is crucial to identity development (Erikson, Reference Erikson1959; Steinberg & Morris, Reference Steinberg and Morris2001), yet they tend to be grouped into studies with younger children or adults. Adolescents with cancer should be considered as a unique group because they tend to experience distress that is more complex, severe, and longer lasting than children or adults with similar diagnoses, and this distress tends to be most prominent after ending active treatment (Sansom-Daly et al., Reference Sansom-Daly, Wakefield and Bryant2012). However, little is known about the unique characteristics and needs of this population as related to anxiety.

ANXIETY DURING SURVIVORSHIP

Although achieving remission is certainly a welcome relief for pediatric cancer patients and their families, the transition into survivorship undoubtedly brings its own set of challenges, such as readjustment to home and family life, re-acclimation to school and social settings, uncertainty about cancer recurrence, and coping with the residual physical effects of treatment. Research to date has typically found adolescent cancer survivors to be psychologically resilient (Phipps, Reference Phipps2007; Kazak et al., Reference Kazak, DeRosa and Schwartz2010; Williams et al., Reference Williams, Allen and Phipps2011); however, there is likely a subset of individuals who experience psychosocial difficulties following their transition into survivorship.

In fact, the period following cancer treatment may leave adolescents particularly vulnerable to developing anxiety and other psychosocial difficulties. A study by von Essen and colleagues (Reference von Essen, Enskär and Kreuger2000) found that survivors of pediatric cancer reported higher levels of anxiety and depression and lower levels of self-esteem than both healthy peers and children currently undergoing cancer treatment. Although these results became statistically insignificant after further analysis, the study's power may have been limited by its small sample size (n = 18). Therefore, further research with a larger sample is necessary to determine if adolescent cancer survivors' rates of psychopathology are truly higher than those of adolescents undergoing cancer treatment and healthy peers. If these findings were replicated, it would indicate that transition into survivorship may be a crucial time to intervene with adolescents who are experiencing psychosocial difficulties, including anxiety.

There has been a fair amount of research about the psychosocial functioning of adolescent cancer survivors. However, to the authors' knowledge, there have been no studies specifically assessing anxiety in this population. This gap in the literature is alarming, as there is meta-analytic evidence that anxiety may be more likely to present as a problem for cancer survivors than depression (Mitchell et al., Reference Mitchell, Ferguson and Gill2013).

This paper will review the relevant literature regarding psychosocial functioning among adolescent survivors of pediatric cancer with the aim of describing current knowledge about anxiety in this population and calling attention to gaps in the literature. An overview of current knowledge about anxiety in adolescent survivors of pediatric cancer is a starting point for the development of anxiety screening and prophylactic treatments for this population, which could prove to be useful in supporting psychosocial adjustment, not only during adolescence, but also as these patients transition into adulthood.

SPECIFIC PHOBIAS

Children and adolescents with cancer typically undergo many painful medical procedures, leaving patients and survivors vulnerable to procedure-related anxiety. In a study of pain management in children ages 3–18 undergoing medical procedures, Weisman and colleagues (Reference Weisman, Bernstein and Schechter1998) found that children younger than eight years who had received the placebo on the first trial continued to feel high levels of pain during subsequent procedures performed with pain management. This pain is likely anxiety related because young children lack the cognitive development to understand that subsequent procedures might not be as painful with proper analgesic medication. Longitudinal research is needed to determine if this effect continues to impact children as they enter adolescence. Additionally, some procedures may be painful enough to cause anxiety even with adequate analgesia. Such distress can lead to anticipatory anxiety, as well as specific phobias of blood, needles, etc., which could make future medical procedures more difficult to withstand (Pao & Bosk, Reference Pao and Bosk2011). Specific phobias relating to medical procedures or medical settings would likely be detrimental to cancer survivors' health, as routine follow-up is necessary for optimal survivorship care.

SOCIAL PHOBIA

After spending a large amount of time in hospitals, doctors' offices, and at home, adolescents may face anxiety in unfamiliar social situations after completing cancer treatment. A large study conducted by Barrera and colleagues (Reference Barrera, Shaw and Speechley2005) found that adolescent cancer survivors were more likely than healthy peers to have no close friends and less likely than healthy peers to use friends as confidantes. Similarly, Shelby and colleagues (Reference Shelby, Nagle and Barnett-Queen1998) found that survivors of acute lymphoblastic leukemia had more difficulty with social competence than healthy peers, as well as more anxiety, depression, and overall internalizing symptoms. Taken together, these findings suggest a high prevalence of social difficulties among adolescent survivors of pediatric cancer. Further research is required to understand the role of internalizing symptoms (including anxiety and, perhaps, social anxiety in particular) as either cause or effect of social difficulties in pediatric cancer survivors.

GENERALIZED ANXIETY DISORDER (GAD) AND PANIC DISORDER (PD)

To the authors' knowledge, no studies have assessed the presence of discrete anxiety disorders such as generalized anxiety disorder (GAD) and panic disorder (PD) in this population. However, there are studies that indicate the existence of various, unspecified anxiety symptoms. These studies point to the presence of increased anxiety in adolescent survivors of pediatric cancer, without specifically assessing for anxiety disorders.

In a large study of pediatric cancer survivors aged 5.8 to 36 years, Koocher and colleagues (Reference Koocher, O'Malley and Gogan1980) found that the majority of participants experienced residual psychosocial sequelae, especially depression, anxiety, and low self-esteem. Participants who were able to articulate the sources of their anxiety mentioned uncertainty about the future, the possibility of recurrence, and troubling memories of stressful aspects of treatment. Interestingly, death anxiety scores for participants were lower than those for a comparable control group of medically healthy peers, which may imply that the disease itself is more difficult to manage than the possibility of death. This study also found that posttreatment psychosocial difficulties became less prevalent as patients got further from the time of diagnosis if they remained free of relapse. Given the broad age range for participants in this study, it is necessary to conduct further, more age-specific research with adolescents in order to determine which of these findings, if any, may be particularly salient for this age group.

A study conducted by Bauld and colleagues (Reference Bauld, Anderson and Arnold1998) compared the psychosocial functioning and coping mechanisms of Australian adolescents previously diagnosed with cancer with that of healthy adolescents recruited from the general population. Their findings generally pointed to normal psychosocial functioning among adolescent cancer survivors. However, this group demonstrated significantly higher state anxiety than healthy peers and scored higher on two negative coping mechanisms: wishful thinking and ignoring the problem. Similar to the findings of Koocher and colleagues (Reference Koocher, O'Malley and Gogan1980), time elapsed since treatment was found to be a significant predictor of psychosocial adjustment, with longer times out of treatment being associated with better psychosocial functioning.

Despite the adolescent survivors' high levels of state anxiety, Bauld and colleagues (Reference Bauld, Anderson and Arnold1998) generally found results that imply psychosocial functioning comparable to that of healthy peers. However, there are two factors to consider when interpreting these results. First, survivors' tendency to avoid problems supports the possibility of increased anxiety, as avoidant behavior is a key feature of anxiety. Therefore, it is possible that adolescent cancer survivors experience heightened levels of anxiety but do not acknowledge these feelings due to their avoidance of anxiety-producing situations. Second, about 59% of the cancer survivors in this study had been out of treatment for more than 5 years. Therefore, results can only be used as a measure of long-term coping. Further investigation is necessary to determine if these results are representative of adolescents in all stages of cancer survival. The results of von Essen and colleagues (Reference von Essen, Enskär and Kreuger2000) suggest that it is unlikely that survivors of all stages will fit a psychosocial profile similar to that of healthy peers. Additionally, Bauld and colleagues' results imply that, even though survivors appear to have good long-term adjustment, it is possible that pervasive anxiety is camouflaged by maladaptive coping mechanisms, such as ignoring the problem or engaging in wishful thinking.

Another recent study examined anxiety symptoms in adolescents with differentiated thyroid cancer (DTC) (Oren et al., Reference Oren, Benoit and Murphy2012). These investigators found that adolescents with DTC do not experience greater anxiety than adolescents with autoimmune hypothyroidism or healthy peers. However, these results may have been limited by a small sample size (n = 16). Furthermore, these findings cannot be generalized to adolescents with other types of cancer.

COMORBID ANXIETY AND DEPRESSION

In addition to the evidence supporting the presence of miscellaneous anxiety symptoms among adolescent survivors of pediatric cancer, it is important to note that major depressive disorder (MDD) is prevalent among cancer patients and survivors (Massie, Reference Massie2004). GAD and MDD are often found comorbidly, both in the general population (Aina & Susman, Reference Aina and Susman2006) and in cancer patients (Cassileth et al., Reference Cassileth, Lusk and Hutter1984). Therefore, it is important to investigate the prevalence of GAD and other common anxiety disorders, such as PD, among adolescent survivors. Future studies with adolescent survivors should also address this gap in the literature.

IMPLICATIONS FOR RESEARCH AND PRACTICE

Overall, research points to normal psychosocial adjustment in adolescent survivors of pediatric cancer. However, there is evidence to indicate a possible tendency toward anxiety among a subset of this population, particularly during the transition to survivorship. Studies to date have not typically differentiated between different types of anxiety; however, it seems that this population may be at risk for many forms of anxiety at both the clinical and subclinical levels. However, there are currently no studies assessing for specific anxiety disorders or the presence of subsyndromal anxiety symptoms in this population, which indicates a large gap in the literature on psychosocial care for adolescent survivors of pediatric cancer.

It is possible that the stress of cancer diagnosis, treatment, and transition into survivorship may cause adolescents to experience a variety of anxiety symptoms. For instance, adolescent survivors of pediatric cancer may experience generalized anxiety, including health-related anxiety or panic attacks. Adolescents who were forced to rely on their parents to a greater extent than same-age peers might experience a sense of separation anxiety when they finally have the opportunity for greater autonomy. Likewise, adolescents may experience social anxiety in relation to the social deficits found by Barrera and colleagues (Reference Barrera, Shaw and Speechley2005) and Shelby and colleagues (Reference Shelby, Nagle and Barnett-Queen1998). These examples are only a few of the ways that anxiety could potentially manifest in adolescent survivors of pediatric cancer.

The recent publication of the DSM–V has created an environment that lends itself to the assessment of psychopathology in populations that have not been thoroughly assessed to date. Examining how adolescent survivors of pediatric cancer fit into the most current standards for anxiety disorders and exploring how anxiety might manifest uniquely in this population are important steps in understanding the psychosocial needs of this potentially vulnerable group of adolescents.

While coping and psychosocial adjustment seem to improve with time, it is important to note that even long-term survivors have been found to employ negative coping mechanisms more frequently than healthy peers. Perhaps early intervention regarding anxiety and other psychosocial difficulties experienced as patients end active treatment can ease the path of adjustment for survivors of pediatric cancer and decrease the likelihood of experiencing residual psychosocial sequelae. Further research is necessary to determine whether the anxiety experienced by adolescent survivors of pediatric cancer tends to be prominent enough to lead to the diagnosis of an anxiety disorder, to assess which anxiety disorders may be prevalent in this population, to explore subsyndromal anxiety symptoms and patterns of anxiety that are unique to this group, to identify their common sources of anxiety, and to assess how anxiety affects the trajectory of their psychosocial development. This information can be used to develop more effective interventions to detect and treat anxiety symptoms at an early stage in order to promote psychosocial well-being throughout all stages of survival and psychosocial development.