Cognitive behavioural therapy for weight gain associated with antipsychotic drugs
Introduction
Overweight and obesity are common concerns in individuals with severe mental disorders (Allison et al., 1999). Obesity is related to a number of factors, including comorbid psychopathology, environmental and behavioural factors, cognitive attitude and beliefs as regards food and body shape, as well as side effects of several medications. In particular, antipsychotic drugs induce weight gain in up to 50% of patients (Baptista, 1999, Baptista et al., 2002) and can lead to abdominal obesity (Allison et al., 1999, Baptista et al., 2002, Stedman and Welham, 1993). Apart from the aesthetic implications, being overweight or obese increases the risk of somatic diseases (Bray, 1985, Kissebah and Krakower, 1994), has an impact on important aspects of health-related quality of life (Kolotkin et al., 2001), compromises adherence to long-term AP therapy (Stanton, 1995, Nasrallah, 2003) and contributes to the incapacity and social stigma associated with severe mental disorders (Strassnig et al., 2003).
The mechanisms of AP that cause weight gain are complex (Aquila and Emanuel, 2000, Werneke et al., 2002) and involve several pharmacological systems (Allison et al., 1999, Nasrallah, 2003).
Nevertheless, weight gain seems to be due mainly to an increase in global caloric intake following increase in appetite (Bromel et al., 1998) and/or alterations of satiety regulation (Leadbetter et al., 1992). No specific carbohydrate craving has been observed and energy expenditure has been found to remain unchanged (Gothelf et al., 2002). Therefore, increased appetite and the patient's dietary intake may be better predictors of weight gain than the choice of a specific AP drug (Aquila and Emanuel, 2000).
Patients frequently report repeated unsuccessful dietary trials (Theisen et al., 2003, Aquila and Emanuel, 2000) in attempts to counter-regulate AP-induced weight gain. Furthermore, long-term impact of individual dietetic consultations, one of the most frequently prescribed interventions (O'Keefe et al., 2003), seems to be modest or even absent for some of the patients (Khazaal et al., 2006a).
The efficacy and safety of pharmacological treatments for obesity in patients with severe psychiatric disorders have not yet been established. Adjunctive use of topiramate, amantadine and nizatidine has shown variable levels of effectivity in inducing weight loss in patients treated with antipsychotic agents. In addition, the use of these agents may be limited by their side effects (Werneke et al., 2002).
Many recommendations have been formulated on how to treat antipsychotic-induced weight gain, including weight monitoring, diet and exercise. However, the effectivity of all these approaches remains uncertain (Green et al., 2000, Blackburn, 2001, Werneke et al., 2003). Studies have been impaired by small sample sizes (Werneke et al., 2003), frequent inclusion of patients living in controlled environments (hospitals, partial hospitalisation programs or residential setting), lack of long-term follow-up (Cohen et al., 2001, Feeney et al., 2003) and the small number of randomized controlled trials (Littrell et al., 2003).
All the interventions focused on weight and included behavioural counselling and energy-restricting diets. Some studies also involved physical exercise (Archie et al., 2003, Littrell et al., 2003, Vreeland et al., 2003, Wirshing et al., 1999). Cognitive interventions were lacking in most studies and, when used, were limited to a motivational approach to modify urges to overeat (Brar et al., 2005) or to a small open label design (Umbricht et al., 2001, Khazaal et al., 2005). In several studies, behavioural interventions led to modest weight loss (Aquila and Emanuel, 2000, Littrell et al., 2003, Rotatori et al., 1980, Vreeland et al., 2003) and also to a reduction of risk factors for long-term poor health such as haemoglobin Alc (Menza et al., 2004). However, the effect (Werneke et al., 2002) of the between group difference was not always significant and, despite some loss of weight, many patients' body mass index (BMI) often remained in the obese range (O'Keefe et al., 2003).
Binge eating disorder (BED) is a provisional new eating disorder diagnosis (Hsu et al., 2002) described in the DSM-IV research criteria. It is characterized by a pattern of recurrent episodes of binge eating with a lack of self-control over eating and distress regarding binge eating. These episodes occur (a minimum of twice a week for at least 6 months) in the absence of purging or any compensatory behaviour characteristic of bulimia nervosa. This disorder is especially prevalent in the obese population seeking treatment for obesity (Hsu et al., 2002, Cargill et al., 1999). The persistence of BED is a contributing factor to the persistence or the recurrence of weight gain (Sherwood et al., 1999, Agras et al., 1997). In the obese population, binge eaters differ from non-binge eaters in some aspects of eating disorder psychopathology and psychiatric comorbidity (Yanovski et al., 1993, Telch and Agras, 1994). Increased tendency towards a negative body image and lower weight self-efficacy are significantly related to BED (Cargill et al., 1999). Furthermore, binge eaters tend to experience a higher level of emotional distress (Freeman and Gil, 2004). Previous studies (Theisen et al., 2003, Ramacciotti et al., 2004, Khazaal et al., 2006d) indicate that binge eating is a common phenotype among severely overweight patients with schizophrenia undergoing antipsychotic drug treatment. This is why we consider it important to assess and treat this eating disorder in these patients.
Patients who gain weight under antipsychotics regularly report unsuccessful dietary trials in attempts to counter-regulate WG (Theisen et al., 2003), which suggests a strong cognitive and behavioural participation in the WG phenomenon. Fear of weight gain (WG) is likely to result in numerous rigid and inadequate attitudes linked to food and weight, in which the person struggles to keep control of his weight and excessively anticipates the occurrence of WG (Mizes and Klesges, 1989). These attitudes have been associated with restraint, which is defined as the intention to consciously restrict food intake in order to maintain body weight or to promote weight loss (Polivy et al., 1988, Westenhoefer, 1991). This phenomenon, as expected in a context of WG, was also found in overweight patients treated with antipsychotic drugs (Khazaal et al., 2006b). Besides, it has consistently been found that restrained eaters show a tendency to overeat under different experimental conditions, such as after food preload, after alcohol consumption and in reaction to dysphoric moods (Westenhoefer, 1991, Ruderman, 1986). Restrained eaters were also found to increase consumption of specific foods in response to related cues (Fedoroff et al., 2003). In addition, several studies showed a correlation between dietary restrained eating and binge eating (Polivy and Herman, 1985), which is associated with obesity (Cargill et al., 1999, Hsu et al., 2002).
One can therefore hypothesize that the attitudes mentioned above only partly explain interindividual weight gain liabilities in patients treated with AP drugs.
Previous studies showed persistence of eating and weight-related cognitions after treatment by moderate calorie-restricted diet (Khazaal et al., 2006c). This leads us to envisage the need for specific cognitive therapy for these particular patients.
To date and to the best of our knowledge, none of the preceding controlled studies have used cognitive therapy in order to modify eating and weight-related cognitions. Moreover, until now, none of these studies have considered outcomes in terms of binge eating or eating and weight-related cognitions. The main aim of this study is thus to assess the effectivity of a handbook on a cognitive and behavioural treatment called “apple-pie group” (CBT) for cognitive distortions related to eating behaviour and weight, binge eating symptomatology and weight loss in patients reporting weight gain during AP treatment.
Section snippets
Study design
This study was approved by the local ethics commission. It is a prospective randomized controlled trial with a six month follow-up period. Eligible patients were randomly allocated to one of the two treatments: CBT (apple-pie group) or brief nutritional education (BNE). After checking the inclusion criteria and receiving the patients' informed consent, patients were assessed before the beginning of the treatment procedure and then at 12 and 24 weeks after inclusion time. It was hypothesized
Results
A total of 128 referrals were screened. Seventy-one of them were identified as being eligible for the study and invited to participate. Of these, 10 refused consent, leaving a sample of 61 patients consenting to randomization (Fig. 1). Socio-demographic and clinical characteristics of the CBT and BNE groups are shown in Table 1. In general, the participants had a relatively long psychiatric history (10.7 SD 9 years). Most were unemployed and a minority lived in a residential setting. The mean
Discussion
To our knowledge, this is the first randomized controlled study on cognitive and behavioural management of AP-induced weight gain in outpatients with persistent mental illnesses. The study highlights the importance of binge symptoms and binge eating, as well as cognitive distortions related to eating and weight in a population undergoing treatment. The accessibility of CBT treatment for these patients is also discussed in this article. The study demonstrates the feasibility of the CBT program
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