Case 1: a complex case with a simple formulation and treatment

BellaFootnote ¹ was a young professional woman, in her mid-20s at the time of referral. She had been diagnosed as suffering from bulimia nervosa since she was 16 years of age, and received a diagnosis of borderline personality disorder within another year. Her presentation was undoubtedly a complex one, with depression and anxiety symptoms (particularly involving obsessive-compulsive features, which approached diagnosable levels for obsessive-compulsive personality disorder). She reported particular difficulties in maintaining interpersonal relationships, mood instability, and anger control. She also had a history of a range of impulsive, self-harming behaviours. The question that will be addressed here is whether her pathology and treatment needs were actually as complex as her presentation might be taken to suggest.

Bella's referral to our clinic was at the age of 27. It was her eighth referral for psychological treatment. Her previous treatments consisted of counselling, cognitive behaviour therapy, two periods of out-patient psychodynamic therapy, schema therapy, two therapies that were hard to label following discussion of their content, and a range of selective serotonin reuptake inhibitor (SSRI) medications. She had never failed to complete a course of treatment, but none had been effective in any clinically meaningful way (according to her referrer and by Bella's own account). She was referred to our clinic part way through her eighth therapy – an 18-month combined day- and out-patient psychodynamic programme – due to fears about her rising clinical risk now that she had entered the out-patient phase. She had returned to her employment as an accountant, but had soon been signed off as sick due to the physical complications of her purging behaviours (inability to be at her desk; frequent passing out). Her pattern of eating was to starve herself for as long as she could, then to objectively binge, vomit, and take very large numbers of laxatives each day.

The request to our clinic was for a period of in-patient treatment for bulimia nervosa, which is uncommon in the UK NHS system. However, given the level of clinical concern, it was agreed to offer Bella a chance to try CBT on an out-patient basis in the first instance, and move to more intensive patient treatment if she was as severe, complex and intractable as she was described as being at referral.

At her initial CBT session, a formulation was developed, including consideration of why Bella had not responded to previous treatments. Such consideration is essential in reaching a clear hypothesis about what is wrong for the patient, as it should help us to stop repeating mistakes. While it was anticipated that Bella would be a complex case, it came as a surprise to realise that Bella had not ever been asked to undertake some basic tasks of therapy for an eating disorder – particularly being weighed and changing her food intake. While not part of some of the therapies that she had undertaken, they should have been present in her previous CBT. In that first session, the role of weighing and the importance of carbohydrate within a balanced dietary intake were explained as being integral to evidence-based CBT for eating disorders (Waller et al., Reference Waller, Cordery, Corstorphine, Hinrichsen, Lawson, Mountford and Russell2007a; Fairburn, Reference Fairburn2008; Waller and Mountford, Reference Waller and Mountford2015). She did not express any reluctance to make these changes – simply surprise at the novelty of being asked to undertake them. She also reported that she did not understand why she was being asked to keep food diaries, as she had done this previously in therapies, but there had been little or no interest in them on the part of her therapists. However, she agreed to complete them once a rationale was given.

This missing element of previous therapies might be understandable in light of the fact that Bella undoubtedly had a complex history, including parental separation, emotionally invalidating environments, a sexually and physically abusive relationship in her mid-teens, and a variable relationship with her four siblings. However, it can be an error to assume that a complex history results in the need for a complex formulation. The formulation that emerged in this session incorporated those experiences as part of her historical antecedents, but there was more emphasis on the here-and-now element of the formulation, which was based on the ‘hot cross bun’ model (Padesky and Mooney, Reference Padesky and Mooney1990). This model was used as a parsimonious starting point for understanding both the bulimia nervosa and the borderline personality disorder symptoms, However, it was accepted that if Bella's case really was complex in the way that had been suggested then there would need to be a development of this model to incorporate more schema-level cognitions that linked her history to her present behaviours, emotions and cognitions.

Therefore, the first few sessions of CBT were an experiment, to determine whether a relatively simple, evidence-based approach to the bulimia nervosa could be effective. If that simple here-and-now formulation was appropriate, then one would hope to see a substantial early reduction in pathological eating behaviours and restrictive eating attitudes (e.g. Raykos et al., Reference Raykos, Watson, Fursland, Byrne and Nathan2013; Turner et al., Reference Turner, Marshall, Wood, Stopa and Waller2016). However, one would also hope to see a reduction in the level of emotional instability (as carbohydrate intake resulted in enhanced serotonin levels; Steiger et al., Reference Steiger, Young, Kin, Koerner, Israel, Lageix and Paris2001; Bruce et al., Reference Bruce, Steiger, Young, Kin, Israël and Lévesque2009) and greater cognitive flexibility (in response to reduced starvation effects; Keys et al., Reference Keys, Brozek and Henschel1950). If those changes were not seen, then the plan was to either broaden the formulation and change the out-patient CBT approach accordingly (e.g., address schemas directly; address emotional intolerance; Corstorphine, Reference Corstorphine2006; Waller et al., Reference Waller, Kennerley, Ohanian, Riso, du Toit, Stein and Young2007b), or to intensify her treatment with an admission to day-patient care.

The first four sessions of evidence-based CBT were highly successful. They involved focusing on the key therapy elements of exposure, nutrition, psychoeducation and risk management. Bella regularly expressed surprise – particularly that by eating in a structured way she not only binged less but did not gain weight. However, she reflected on the fact that this was one of the possible outcomes of her changing her eating that had been predicted, based on the relatively simple here-and-now formulation. Equally important, her mood stabilized rapidly, her impulsive behaviours ceased (outside of her bulimic behaviours, which carried on until about the 14th session, although at a much lower level), her anxiety levels fell, and her cognitive capacity increased. In short, her bulimic features changed at the speed that one would expect in a relatively straightforward case of bulimia nervosa, but her apparent complexity (co-morbid axis 1 and axis 2 disorder features) fell away even more quickly. This is compatible with the finding of Turner et al. (Reference Turner, Marshall, Wood, Stopa and Waller2016) that early change in eating attitudes in evidence-based CBT is associated with reduction in personality disorder pathology.

Bella remained in routine CBT until her eating difficulties had resolved and her body image had normalized (approximately 25 sessions). At 6-month follow-up, Bella had not relapsed, even though she had had to cope with the anxiety that she experienced as she formed and maintained a relationship (which went on to be long term).

Case 2: a case with physical co-morbidity

There are a number of issues that need to be considered when working with patients with eating disorders and diabetes mellitus (Peveler and Fairburn, Reference Peveler and Fairburn1992; Fairburn, Reference Fairburn2008), as detailed earlier. Complexity arises from the interaction between the two disorders, the potentially serious physical health complications, and the subsequent implications when using a cognitive behavioural approach. Close liaison and a shared understanding of the treatment rationale between teams is crucial, particularly as improvements to food intake may affect glycaemic control, potentially requiring amendments to be made to the patient's insulin regime during treatment (Peveler, Reference Peveler2000). Finally, the patient's previous experience of diabetic services and pattern of engagement in their own care can also affect engagement (Peveler and Fairburn, Reference Peveler and Fairburn1992; Peveler, Reference Peveler2000; Custal et al., Reference Custal, Arcelus, Aguera, Bove, Wales, Granero, Jimenez-Murcia, Scanchez, Riesco, Alonso, Crespo, Virgili, Menchon and Fernandez-Aranda2014; Colton et al., Reference Colton, Olmstead, Wong and Rodin2014).

Sally was referred to the eating disorders service by her family doctor, who had known her for over 20 years. Although Sally had requested the referral herself, the referral letter conveyed a sense of apologetic defeatism – emphasizing Sally's long history of non-engagement with services and chronic self-neglect regarding the management of her diabetes, which had resulted in a number of serious physical health conditions. The physical risks arising from her co-morbidity resulted in Sally being assessed urgently. It should be noted that clinicians working with eating disorders are likely to need adequate knowledge about diabetes and the associated medical risks, so that they can assess and treat such a case regardless of their professional background (Fairburn, Reference Fairburn2008).

Sally is a single mother in her mid-30s, with three children. At assessment, she was diagnosed with bulimia nervosa of 18 years duration, with type 1 diabetes mellitus that had started two years prior to the onset of her eating disorder. Sally was following a restricted eating regime, bingeing two to three times a week, and engaging in a number of compensatory behaviours (vomiting, laxatives, exercise). She had typical weight and shape concerns, and was highly fearful at the prospect of weight gain. Until recently, Sally had never disclosed her eating disorder and had therefore never received any help in the past. She acknowledged omitting insulin as an additional method of controlling her weight, which she was trying to maintain under a BMI of 19.5. She reported high levels of perfectionism, low self-esteem, and poor emotion regulation skills

After initially engaging with her insulin regime on being newly diagnosed with Type 1 diabetes – which resulted in a rapid weight gain - Sally thereafter only sporadically engaged with diabetic services and her recommended insulin regime. Poor engagement with her diabetes regime had resulted in numerous admissions for diabetic ketoacidosis (the build-up of toxic levels of ketones, as the body digests fatty acids, due to the lack of access to or ability to process carbohydrates, resulting in confusion and cerebral oedema). Over time, the diabetes led to a number of longer-term medical complications, including a below-knee amputation, extensive retinal damage and urinary incontinence. At the time of her assessment, Sally was omitting her insulin on approximately half the days of the week, often in response to feelings of anger, resulting in very unhealthy HbA1c levels of over 13% (target range <6.5%; National Institute for Health and Care Excellence, 2015). She had not told the diabetes team about her eating disorder.

Given the long duration of bulimia, her poorly controlled diabetes, and her poor engagement in treatment and self-care, it was easy to see Sally's case as a complex one. The initial session focused on identifying and developing her goals for treatment, which included improving insulin compliance and reducing bulimic symptoms but without weight gain. A simple hot cross bun formulation was used at this stage, to reduce the risk that Sally would be overwhelmed if it were more complex. The session also addressed the rationale of the CBT approach and the necessary tasks of treatment (e.g. food diaries; reading relevant psychoeducation material; monitoring injection use and blood sugar levels; making changes to the structure, quantity and variety of her food intake; Waller et al., Reference Waller, Cordery, Corstorphine, Hinrichsen, Lawson, Mountford and Russell2007a; Fairburn, Reference Fairburn2008). These tasks were presented to Sally as a choice and an experiment, and she agreed to undertake them. She also consented to the diabetic team being made aware of her eating disorder, the initial treatment plan and the underlying rationale.

Clinically, there was a concern that Sally might be agreeing to engage in change based on the relatively simple formulation, but might actually implement it for extraneous reasons (e.g. feeling angry at her position). The reason for this concern was that Sally had been given straightforward advice about managing her diabetes on many occasions over the years, but had not engaged with those management plans. Therefore, it was decided that engaging her by making her actions feel understood might be more successful than simply telling her what she needed to do. In particular, it was clear that Sally herself did not see the bulimia nervosa and diabetes as having been linked over the years.

Consequently, the second session included the development of a more detailed, longitudinal formulation that considered functional links between the diabetes mellitus and bulimia nervosa. A key early trigger to the onset of the bulimia was losing a significant amount of weight as her diabetes developed, which she experienced as highly positively reinforcing. In contrast, the treatment for her diabetes (i.e. using insulin) resulted in rapid weight gain, which she found distressing. She also disliked having to monitor her sugar levels and experienced other people's reaction and involvement in the management of her condition as intrusive and controlling. Sally felt ‘different’ and ostracized by her peers for ‘being diabetic’ and quickly began to feel very negative about her diagnosis. Teasing for the rapid gain in weight precipitated her first attempt to lose weight via dieting. Sally quickly discovered that she could lose more weight by omitting to take her insulin, but this resulted in episodes of binge eating, and then the use of a range of compensatory behaviours. Current triggers to her bulimic behaviours were identified using monitoring sheets, and centred on insulin omission and hunger due to restriction. Other triggers included emotional cues, resulting from interpersonal dynamics and difficulties asserting or expressing herself. Restriction and insulin omission also seemed to function to regulate difficult emotions, often in a self-punishing way. Finally, a dichotomous cognitive style underpinned an ‘all or nothing’ approach to the management of her insulin, strict food rules and exaggerated emotional response.

This more complex longitudinal formulation reflected the complexity of Sally's history and presentation, and played a key role in helping Sally feel that her difficulties made sense. However, it was the more straightforward ‘hot cross bun’ formulation that was used to direct the key elements of Sally's treatment, again reflecting the theme that relatively complex cases can often be best treated using a more straightforward approach, even where physical conditions might slow progress.

The treatment began with stabilizing her nutritional state and hypoglycaemia in order to reduce her bulimic symptoms, teaching her about healthy eating and use of insulin. Intake monitoring, dietary change and gradual improvement in her insulin use (in collaboration with her diabetes team) were used to achieve that goal. This dietary change was achieved by starting with relatively ‘safe’ foods that Sally could tolerate and using distraction techniques to assist with her anxiety over delivering her insulin injections. After 3–4 weeks, she had achieved regular eating, leading to a rapid reduction in the number of binge eating episodes and providing her with an early sense of success and self-efficacy. She also started to notice some small but significant improvements in her physical wellbeing as a result of improving her food intake and increasing the regularity of long-acting insulin injections.

The next few sessions were interrupted by hospitalizations due to urinary tract infections. However, Sally continued to use her understanding of the core formulation of her difficulties to work on increasing her use of short acting insulin (raised to three injections a day). She experienced some dramatic changes in her weight over this time, but the weight chart was used to help Sally learn that her weight began to stabilize as her insulin use became more regular.

By session 18 (held over 26 weeks, due to her illness), Sally was eating regularly with no reported incidents of binge eating over the past 19 weeks, and only two to three isolated incidents of self-induced vomiting. She was 90% compliant with her insulin regime and HbC1a levels had fallen to 9%. Attention then turned towards targeting food avoidance (using a food re-inclusion programme based on the list of feared foods that Sally had previously compiled) and the emotional dysregulation that was associated with the residual incidents of self-induced vomiting.

Around this time, Sally was re-admitted to hospital and had to miss the next four sessions due to illness. She did not respond to appointment letters or attempts to contact her, and was subsequently coded as having dropped out of treatment. However, she was re-referred to the service two years later with a query regarding a re-emergence of bulimic nervosa after a recent hospital admission following a violent episode of vomiting. At this further assessment, Sally emphasized that she did not think she had an eating disorder any longer. Since dropping out of treatment with the eating disorders service, she had maintained her insulin regime well, as shown by her current HbA1C level of 5.5% and reported feeling much more positive about her diabetes management. Her eating disorder symptoms had remained at the level where she had ended treatment – no bingeing, no laxative abuse, and vomiting only once or twice a month. Her weight was relatively stable and in the normal range. However, she had retained her focus on ‘safe’ foods. Her referral had resulted from her remaining vomiting episodes, which were emotionally driven and were occasionally severe and resulted in hospitalization. In short, her initial treatment, based on a straightforward CBT formulation and approach, had resulted in stable gains, even though not all symptoms had been alleviated.

Sally was accepted for further treatment to address the residual problems. Following a review of how well she had progressed with her ‘hot cross bun’ formulation, a ‘mini formulation’ was used. It demonstrated how negative mood states were often precipitated by interpersonal interactions during which Sally felt unable to assert herself. Subsequent work focused on targeting residual food avoidance and introducing emotional regulation skills using the standard CBT approach (Fairburn, Reference Fairburn2008), supplemented with some related dialectical behaviour therapy skills (Linehan, Reference Linehan1993). Finally, a problem-solving approach was adopted towards interpersonal triggers, using assertiveness techniques such as role play and interpersonal behavioural experiments. Sally was subsequently discharged from the service having attended a further 18 treatment sessions. She was able to eat a wide variety of foods with little or no anxiety, and there had been no further incidents of self-induced vomiting. Sally also reported an increased sense of interpersonal effectiveness, resulting in a reduction in the number of urges to engage in self-punishing behaviours and had a range of other strategies with which to manage her emotions.

Case 3: a less typical presentation

John, 28 years old, has never received any psychological intervention before. He described being a ‘fussy eater’ since his early childhood. However, his difficulties had become more pronounced approximately four years ago. At assessment, John had a BMI of 16, having gradually lost weight from a BMI of 20 over the preceding years. He described a very rigid and restrictive diet and was extremely fearful of the consequences of changing his eating. However, he had no body image issues beyond a desire to get back to a normal weight, nor did he demonstrate the cognitions that would normally underpin a diagnosis of anorexia nervosa. Rather, his concerns centred on anxiety. John reported severe abdominal pains, including beliefs that certain foods might harm him. He was pre-occupied with his bowel movements and was fearful of both diarrhoea and constipation (which he did experience, most likely connected to his disturbed gastrointestinal functioning). John reported that he was unhappy with his appearance and would like to weigh more. He was no longer able to work and was increasingly pre-occupied with researching his physical health on the internet. John had visited several nutritionists over the years and had become increasing confused by the varying and sometimes contradictory advice he received. John did not think he had an eating disorder, but was open to the idea that psychological therapy might be of benefit. He was diagnosed with ARFID, although the clinician was open in acknowledging his ambivalence regarding this. Given that there was no evidence for the over-evaluation of control of eating, shape and weight that underpins most models of CBT for eating disorders, a CBT model for health anxiety/obsessional problems was utilized.

In the early sessions, time was taken to build the therapeutic relationship, take a history, and understand John's perspective and beliefs regarding his difficulties. Together, a hot cross bun formulation was developed with a particular emphasis on physical symptoms and John's beliefs around these. Following this, psycho-education was used via a Socratic approach. John and his therapist explored the impact of semi-starvation on his gut functioning and cognitive ability, explaining how his low weight made flexible thinking harder and increased development of rigid rules around eating. The therapist discussed the ways in which increased physiological arousal, highly focused attention on the body and misinterpretation of bodily symptoms were maintaining John's beliefs. The therapist then used the CBT model to show that there might be two possible hypotheses regarding what was driving John's difficulties. First, as John believes, there could be something seriously wrong with his physical health (Theory A). Second, it could be that he is worried about and believes that there is something seriously wrong with his physical health (Theory B). This can be framed as Theory A versus Theory B. These alternative explanations are linked to the hot cross bun formulation and to psycho-education. The therapist also explained how changing his eating is likely to alter gut functioning, increasing his focus on his physical sensations, at least in the short term. Although John strongly believed Theory A, he was willing to engage with the therapist in behavioural experiments to evaluate the two theories. John also met with the dietitian, who was able to help resolve some of John's confusion regarding the multiple sources of advice he had received. Therapy continued with the main elements of CBT (food diaries, recording and monitoring of thoughts and physical sensations, behavioural experiments to test out beliefs and rules, and graded hierarchy to increase quantity and variety of food), focusing on the exposure to anxiety element of such treatment. There was an active focus on weight gain. Towards the end of therapy, a broader approach was adopted to support John to explore voluntary work and build social networks to reduce the risk of relapse and pre-occupation with his body and physical sensations.

John attended for 20 sessions. His belief in Theory B gradually increased and his eating is much improved. He improved his weight to BMI = 18, and continued to gain during follow-up.