A learning model of binge eating: cue reactivity and cue exposure - Jansen (1998) - Article

Introduction

This research hypothesizes that the craving and excessive food intake of binge eaters is cue controlled and might be successfully treated with cue exposure and response prevention. Exposure has been shown to be a highly effective strategy when aiming to reduce fear and avoidance behavior. Exposure therapy follows from the idea that the anxiety and avoidance behavior are typically cue-controlled. During exposure the subject is exposed to the feared cue (stimulus) and avoidance behavior is prevented. Recent research in the field of addictive disorders suggests that the craving and substance intake of many addicts, like binge eating, is cue-controlled. In order to be diagnosed as suffering from binge eating, the criteria of eating a large amount of food during a binge and a sense of lack of control over eating should be appearent. Binge eating may occur in all eating disorders, amongst which are bulimia nervosa and anorexia nervosa.

Cue reactivity

Binge eating has repeatedly been considered very similar to drug abuse, because in both cases individuals feel an almost irresistible urge and loss of control over their intake. Both behaviors show autonomic responding, such as increades heart rate, to addiction-related cues. Most cue reactivity is classically conditioned. This includes that cues which are (nearly) always and exclusively present at the time of drug administration will acquire the ability to predict the administration and effects of the drug. However, cue reactivity will only be learned when the drug administration can be reliably predicted.

Binge eating and cue reactivity

Findings on the eating behavior of binge eaters indirectly support that the classical conditioning model of binge eating exists. Binge eaters usually alternate between binge eating and dieting episodes. Such an eating pattern facilitates classical conditioning: both deprivation as well as eating large amounts (strong unconditioned stimuli) within a limited and specific range of cues (conditioned stimuli) have the implication that classical conditioning will be strong. Strong conditioning will result in strong conditioned responses which are supposed to be experienced as an intense urge to eat. However, the learning model of binge eating off€ers an unifying explanation for the collection of disinhibitors that have been identified in binge eaters. The conditioned stimuli are assumed to elicit cue reactivity (autonomic and/or biochemical responses which are subjectively experienced as craving) and, therefore, lead to binge eating. Binge eating might be successfully treated with cue exposure and response prevention.

Predictions

The learning model of binge eating predicts that:
(1) classical conditioning of food intake (unconditioned stimulus) to exteroceptive or interoceptive stimuli (conditioned stimulus) will result in cue reactivity
(2) after multiple disinhibitors (conditioned stimuli like thinking of binging food and smelling or tasting a priming dose) binge eaters will show cue reactivity
(3) inducing autonomic and/or biochemical cue reactivity in normal eaters will be experienced as an intense urge to binge and trigger an overeat response.
(4) treatments which fail to reduce cue reactivity will have higher rates of relapse than treatments which are successful in the reduction of cue reactivity. This predicition is linked to the fact that in vivo exposure given in various anti-phobia treatments was the best predictor of succes. From the present model described here, it can also be predicted that treatments are effective to the degree in which they include exposure.

Cue-exposure with response prevention

Practical aspects

The learning model of binge eating concludes that cue reactivity follows from the link between conditioned (CS) and unconditioned stimuli (US). The cues will elicit reactivity as long as the conditioned stimulus are systematically reinforced by the unconditioned stimulus. The model states that the cue reactivity will extinguish when the CS-US bond is broken by prolonged non-reinforced exposure to the conditioned stimuli. Therefore, Thus, the subject should be exposed to the cues but prevented from substance use for cue exposure. The treatment inferred from the model is essentially the same as current treatments for phobias and obsessive compulsive disorders. The exposures must be performed in vivo as far as possible. Various studies with anxiety patients and substance abuse patients indicate that in vivo exposure is more eff€ective than in vitro exposure, by which the cues are only present in the mind. It is recommended to come as close as possible to the regular bingeing situation by recruiting as many cues as possible. Furthermore, exposure will not succeed unless the sessions are prolonges at relatively short intervals.

Empirical status

Several findings from small-scale pilot studies on cue exposure with response prevention for binge eaters conclude that cue exposure may be an eff€ective treatment for binge eaters. However, large controlled clinical trials are needed in order to generalize this conclusion.

Concluding remarks

Proper large-scale, controlled data on the eff€ectiveness of the treatment of binge eating on noth the short and long term is needed. Furthermore, studies on the e€ffectiveness of cue exposure should measure all relevant symptoms of binge eating, including general psychopathology, eating pattern of binge eaters, weight control methods, self-esteem and body weight and shape concern. The combination of both cue exposure and body image therapy, directly focuses at the two main symptoms of eating disorders: binge eating (combating with cue exposure) and dysfunctional cognitions concerning body shape and weight (combating with body image therapy) and thus might be a very eff€ective cognitive behavior therapy.

Bulletpoints

• In order to be diagnosed as suff€ering from binge eating, a large amount of food is eaten during a binge and a sense of lack of control over eating is experienced. Binge eating may occur in all eating disorders, amongst which are bulimia nervosa and anorexia nervosa.
• Most cue reactivity is classically conditioned. This includes that cues which are (nearly) always and exclusively present at the time of drug administration will acquire the ability to predict the administration and e€ffects of the drug.
• For cue exposure, the subject should be exposed to the cues but prevented from substance use.
• Binge eating might be successfully treated with cue exposure and response prevention.
• However, large controlled clinical trials are needed in order to generalize this conclusion.

ExamTickets

• Know the difference between in vivo and in vitro exposure.
• Know how to explain why the learning model of binge eating includes in vivo instead of in vitro exposure.
• Know on which two elements the therapy of binge eating should focus.