Etiology of Abnormal Psychology - Anorexia Nervosa

Anorexia Nervosa - DSM

Anorexia nervosa (AN) is a serious eating disorder characterized by self-starvation and excessive weight loss. According to the DSM-5, it is diagnosed by three criteria: restriction of food intake leading to significantly low body weight, intense fear of gaining weight, and a distorted perception of body image or a lack of recognition of the seriousness of low body weight. Diagnosis is often delayed because many individuals with AN are unaware of the severity of their condition (anosognosia) and do not seek help until their health deteriorates. Anorexia has two subtypes: the restricting type and the binge-eating/purging type. It is associated with high physical risks, including heart failure and infertility, and has the highest mortality rate of any psychiatric disorder.

biological explanation → genetic explanation

Recent research challenges the early belief that anorexia nervosa (AN) is caused solely by environment and upbringing. Genetic studies show that anorexia runs in families, with relatives of individuals with AN having a 10 times greater risk of developing the disorder. Specific variations on chromosome one, which influence appetite, satiety, anxiety, and depression, are commonly found in people with anorexia, suggesting that disruptions in biological signaling pathways may trigger the disorder. Twin studies are often used to examine the heritability of anorexia by comparing concordance rates between monozygotic (identical) and dizygotic (fraternal) twins; consistently higher concordance rates in monozygotic twins further support a genetic contribution to the disorder.

biological explanation → genetic explanation → evaluation

Strengths:

• Strong evidence from twin and family studies.

• Genetic markers (e.g., serotonin receptors) associated with AN.

• Supports the idea that genes play a significant role in the disorder.

Limitations:

• AN is a complex disorder influenced by both genetic and environmental factors.

• Studies show correlation, not causality (genetic factors don't directly cause AN).

• Environmental factors (e.g., societal pressures) also play a crucial role.

biological explanation → genetic explanation → holland et al (1988)

Aim: To investigate if MZ twins (who share 100% of their genes) have a higher concordance rate for anorexia nervosa than DZ twins, suggesting a genetic link.

Procedure:

• Studied 45 female twin pairs (25 MZ, 20 DZ), with at least one twin diagnosed with anorexia.

• Twins were interviewed separately using a structured DSM-III-based diagnostic interview and questionnaires on eating habits and personality.

• Family history of psychiatric disorders was also collected.

Results:

• 56% concordance for MZ twins vs. 5% for DZ twins.

• MZ twins had lower BMI and higher "drive for thinness" and "body dissatisfaction" scores.

• Higher prevalence of anorexia among first- and second-degree female relatives compared to the general population.

Conclusion:

• Genetic factors likely play a major role (estimated 80% heritability), but environmental factors are also important since concordance was not 100%.

biological explanation → genetic explanation → holland et al (1988) → Evlauation

G – Generalisability:
The sample only included female twins, limiting generalisability to males or non-twin populations. Also, some twins were volunteers, which may introduce volunteer bias.

R – Reliability:
Structured diagnostic interviews and standard questionnaires were used, improving reliability. However, self-reports on eating behaviors can still introduce some inconsistency.

A – Application:
Findings support the idea of a genetic predisposition to anorexia, which can inform early intervention and treatment strategies focusing on genetic risk factors.

V – Validity:
High internal validity due to separate interviews reducing contamination. However, other shared environmental factors (e.g., upbringing) could also influence results, not just genetics.

E – Ethics:
There are no major ethical concerns reported, but discussing sensitive topics like eating disorders could have been distressing for participants.

biological explanation → serotonin hypothesis

The serotonin hypothesis explains anorexia nervosa through abnormal serotonin levels. High serotonin is linked to appetite suppression, anxiety, and obsessive behaviors, which are common in anorexia. Restricting food intake is thought to reduce serotonin, temporarily relieving anxiety. People with anorexia may have a variant of the 5-HT2A receptor gene, increasing serotonin activity and sensitivity, leading to higher anxiety when serotonin spikes. During starvation, the brain increases serotonin receptors, making individuals more sensitive to serotonin when they eat, causing emotional distress and reinforcing food restriction

biological explanation → serotonin hypothesis → evaluation

• There is biological support (e.g., genetic evidence) and it explains why eating causes anxiety in anorexia.

• However, it’s unclear if serotonin issues cause anorexia or result from it.

• It ignores social and cultural factors that also influence the disorder.

biological explanation → serotonin hypothesis → Bailer and Kaye (2001)

AIM:
To investigate the role of serotonin in AN and how serotonin levels might relate to symptoms like anxiety, depression, and food intake regulation.

PROCEDURE:

• 90 participants (30 each with AN, BN, and healthy controls), aged 18-27, from similar backgrounds.

• Neuroimaging was used to measure serotonin receptor availability and function.

• Psychological assessments included structured interviews and the Eating Attitudes Test (EAT), which evaluated eating behaviors, weight concerns, and psychological symptoms.

RESULTS:

• Participants with anorexia nervosa had higher serotonin levels than both healthy controls and those with bulimia nervosa.

• Elevated serotonin levels in individuals with AN were linked to greater anxiety.

CONCLUSION:
Serotonin plays a crucial role in the neurobiology of eating disorders. The altered serotonin receptor availability could influence mood and eating behaviors, which could guide future treatment strategies.

biological explanation → serotonin hypothesis → Bailer and Kaye (2001) → Evaluation

Generalizability:

• The sample (90 participants) may not represent all people with eating disorders, as it was limited in age and background.

Reliability:

• Neuroimaging techniques and structured interviews are reliable methods for measuring serotonin levels and eating behaviors.

Applications:

• Findings suggest serotonin plays a key role in eating disorders, potentially guiding future treatments.

Validity:

• The study has good internal validity, but self-report tools like the EAT may introduce response bias.

Ethical Considerations:

• Informed consent was obtained, but the study involved vulnerable individuals, so emotional support was necessary.

cognitive explanation → schema explanation

The cognitive explanation of anorexia nervosa (AN) suggests that individuals with the disorder often have distorted schemas, particularly regarding body image. A schema is a mental representation shaped by past experiences, helping individuals interpret their surroundings. In AN, faulty schemas lead to the Body-Image Distortion Hypothesis, where individuals perceive their body size inaccurately, often overestimating it. This distortion contributes to the development and persistence of eating disorders, as body dissatisfaction is a key factor. The impairment in both the body schema (how the brain perceives the body’s position and size) and body image (the mental perception of the body) is common in AN. These cognitive distortions contribute to the maintenance of anorexia nervosa even after treatment.

cognitive explanation → schema explanation → evaluation

Strengths:

• Provides an explanation for body image disturbance in anorexia.

• Body-image distortion helps understand both development and maintenance of the disorder.

Limitations:

• Causality is unclear—whether cognitive distortions cause anorexia or result from it.

• Overemphasis on internal cognitive processes, ignoring genetic, biological, and environmental factors.

• Doesn’t account for individual differences in cognitive distortions.

• Limited focus on sociocultural influences, which play a significant role.

cognitive explanation → schema explanation → McKenzie et al. (1993)

• AIM: To investigate three aspects of body image in women with eating disorders: body size/shape perception distortion, accuracy of body size estimation, and differences in ideal body image.

• METHOD:

  • Participants: 24 women with eating disorders (treatment clinic patients) and 24 control women without eating disorders.

  • Tasks:

    • Body size estimation: Participants estimated their own body size and shape, and that of other women, using body silhouette images.

    • Ideal body image: Participants indicated their ideal body shape to identify the gap between perceived and desired body size.

    • Comparison: Participants compared their body size with others in their peer group and society.

• RESULTS:

  • Women with eating disorders showed significant body image distortion, underestimating their size, even when underweight or at a healthy weight.

  • These women overestimated their body size compared to others, while the control group had a more accurate self-perception.

• CONCLUSION:

  • Body image distortion is prominent in women with eating disorders, leading to unrealistic body ideals and negative outcomes like low self-esteem and depression.

  • Addressing body image distortion is key in treatment, aiming to improve self-perception and reduce psychological distress.

cognitive explanation → schema explanation → McKenzie et al. (1993) → Evaluation

• Generalisability: Small sample size (48 women), all female and from eating disorder treatment clinics, limiting generalisability to broader or male populations.

• Reliability: Structured methods and standardized tasks increase reliability, but self-reports may introduce bias or inaccuracies.

• Application: Findings highlight the need for treatments that address body image distortion, improving intervention strategies for eating disorders.

• Validity: High internal validity due to control group, but ecological validity may be low due to the artificial setting of the study.

• Ethics: The study seems ethically sound with informed consent, but care must be taken when discussing body image to avoid distress in participants.

Cognitive Explanation → Attentional Bias

Attentional Bias in Anorexia Nervosa (AN):

• Definition: Tendency to focus on certain stimuli while ignoring others.

• In AN:

  • Focus is often on body image and food-related thoughts.

  • Linked to cognitive traits like perfectionism and need for order.

  • Leads to obsessive thoughts about weight loss.

  • Individuals may ignore negative consequences of restrictive eating.

• Research Methods:

  • Modified Stroop Tasks:

    • Food Stroop Task and Body Stroop Task.

    • Participants name the color of food/body-related words.

    • Longer response times → Stronger attentional bias.

• Impact:

  • Reinforces disordered thinking.

  • Contributes to persistence of unhealthy behaviors.

  • Hinders recovery from AN.

Cognitive Explanation → Attentional Bias → evaluation

• Strengths:

  • Supports Cognitive Understanding: Explains how individuals with anorexia focus on specific body image or food-related aspects, reinforcing disordered behavior.

  • Objective Measurement: Tasks like Food Stroop Task and Body Stroop Task provide quantifiable data on attentional bias.

  • Therapeutic Application: Insights into attentional bias can inform therapies (e.g., CBT) to challenge distorted thinking and improve behavior.

• Limitations:

  • Cause or Effect? Unclear whether attentional bias causes anorexia or is a consequence of the disorder.

  • Limited Real-World Application: Laboratory tasks may not fully reflect real-world cognitive processes affecting eating and body image.

  • Overemphasis on Cognitive Factors: The focus on cognition may neglect other factors (e.g., genetics, social pressures, family) contributing to anorexia.

Cognitive Explanation → Attentional Bias → Stormark & Torkildsen (2004)

• Aim:

  • Examine attentional biases to food-related stimuli in women with eating disorders using the Stroop test.

• Method:

  • 20 women with eating disorders and 24 control participants.

  • Stroop Test Variations:

    • Color Stroop Test: Identify the color of words.

    • Food Stroop Test: Identify the color of food-related words.

    • Neutral Stroop Test: Identify the color of neutral words.

  • Additional version where participants identified the color of food and neutral pictures.

  • Reaction times to food vs. neutral stimuli were recorded.

• Results:

  • Women with eating disorders took significantly longer to identify the color of food-related words and images compared to neutral stimuli and the control group.

• Conclusion:

  • Women with eating disorders show over-attention to food-related stimuli, suggesting cognitive biases may contribute to the preoccupation with food and maintenance of disordered eating behaviors.

Cognitive Explanation → Attentional Bias → Stormark & Torkildsen (2004) → Evaluation

• Generalizability: The study’s inclusion of a control group enhances its generalizability, but the small sample size and the exclusive focus on women limit the ability to apply findings to other groups (e.g., men or different cultures).

• Reliability: The Stroop test is a reliable and standardized cognitive task, but the absence of test-retest procedures means we can't confirm the consistency of the results over time.

• Applicability: The findings are useful for understanding eating disorders and could inform treatments like cognitive behavioral therapy. However, the study only focused on food-related stimuli, which may limit its broader applicability.

• Validity: The study’s experimental design is valid, with clear variables and measurements. However, it doesn’t explore the psychological reasons behind attentional bias, limiting the depth of the conclusions.

• Ethics: The study seems to follow ethical guidelines, though participants with eating disorders could have been vulnerable to emotional distress. Adequate support and debriefing would be essential.

• Sociocultural: The study’s focus on women is relevant due to the higher prevalence of eating disorders in this group, but it doesn't address potential gender differences, and its findings may not apply to men.

Sociocultural explanation → Social cognitive theory(SCT)

• SCT Overview:

  • Behaviors are learned through observation and imitation of others.

• Application to AN:

  • Individuals observe unhealthy eating habits in media and social environments.

  • Slim body ideals are often portrayed as desirable or "normal."

  • Leads to cognitive shifts → Restrictive eating behaviors.

• Role of Models:

  • People with eating disorders/unhealthy habits act as models.

  • Influence can be:

    • Direct: e.g., bullying about weight.

    • Indirect: e.g., receiving praise/compliments for slimness.

• Reinforcement:

  • Compliments boost self-efficacy and motivation.

  • Encourages continued disordered behavior.

• Outcome:

  • Cycle of modeling + reinforcement maintains AN behaviors.

Sociocultural explanation → Social cognitive theory(SCT) → Evaluation

• Strengths:

  • Highlights the role of observation and imitation in learning disordered behaviors, explaining how people may internalize unhealthy eating habits.

  • Emphasizes the importance of reinforcement (praise, compliments) in maintaining behaviors like restrictive eating.

  • Provides insight into how societal and media ideals contribute to the development of anorexia.

• Limitations:

  • Oversimplifies the causes of anorexia by focusing mainly on social influences and not accounting for genetic, biological, and psychological factors.

  • Not everyone exposed to thin ideals or eating disorders develops anorexia, suggesting that other factors (e.g., individual susceptibility, cognitive patterns) are also important.

  • Focuses on social learning but may not explain why certain individuals are more vulnerable to the disorder than others.

Sociocultural explanation → Social cognitive theory(SCT) → Becker et al (2002)

Aim:

• to investigate the changing attidues to body image among fijian school girls as a result of the introduction of televison

Method:

• 60 fijian school girls some in 1995 and some in 1998 (before and after TV was intorduced)

• in 1995 particpents were given the EAT-26 to establish eating habits, with a follow up interview to confirm the results

• in 1998 this was repeated with the other cohort, with additional questions about weight and body image

Results:

• Avreage score for EAT-26 went from 13% to 29% (where >20% is correlated with dieting and self induced vomiting )

• 77% of girls said that TV made them think diffrently about their body and there was a genral lack of understaning of TV editing, many of the paricpents said they wanted to look nice like the people on TV

Conclusion:

• the introduction of TV in Fiji lead to sociotal norms being internalised, leading to an increase in the prevalence of eating disorders such as AN

Sociocultural explanation → Social cognitive theory(SCT) → Becker et al (2002) → Evaluation

• Generalizability: The study's findings are valuable for understanding media's influence on body image in a non-Western context, but the small sample of Fijian schoolgirls limits generalization to other populations.

• Reliability: The use of the EAT-26 questionnaire and structured interviews enhances reliability. However, self-report data might introduce biases, like social desirability.

• Application: The study has practical implications for media literacy programs and body image interventions. However, its findings might not apply to cultures less influenced by media.

• Validity: The study’s longitudinal design and use of both qualitative and quantitative data improve internal validity. But confounding factors, such as other social influences, might affect the results.

• Ethical Considerations: The study appears to follow ethical guidelines, especially given that it involves minors. However, questions about body image could have caused distress for some participants.

Sociocultural explanation → Adverse childhood experiences(ACEs)

Adverse Childhood Experiences (ACEs) and Anorexia Nervosa (AN):

• Definition of ACEs:

  • Traumatic/stressful childhood events (e.g., violence, divorce, abuse).

  • Often occur in chaotic, unpredictable environments.

• Psychological Impact:

  • Leads to emotional instability.

  • Common emotional outcomes:

    • Powerlessness, shame, guilt, low self-esteem.

  • Overwhelms emotional processing, causing chronic stress/anxiety.

• Coping Mechanism:

  • Development of a need for control, especially over food.

  • Restrictive eating used as a way to regain control.

Sociocultural explanation → Social cognitive theory(SCT) → evaluation

Strengths:

• Real-world application: The theory helps explain how childhood trauma can lead to eating disorders and informs therapeutic approaches.

• Biopsychosocial model: It integrates psychological and environmental factors, offering a holistic view of anorexia's development.

• Empirical support: Research has shown a correlation between ACEs and eating disorders, supporting the theory.

Limitations:

• Causality: The theory doesn’t establish a clear cause-and-effect relationship, as not everyone with ACEs develops anorexia.

• Overgeneralization: It oversimplifies the link between trauma and eating disorders, ignoring other contributing factors.

• Individual differences: The theory doesn’t account for personal traits or coping mechanisms that may affect how trauma influences anorexia.

Sociocultural explanation →Adverse childhood experiences(ACEs) → Guillaume et al (2016)

Aim:

• Investigate how different Adverse Childhood Experiences (ACEs) uniquely affect the severity of eating disorder (ED) symptoms.

Method:

• 192 female participants with eating disorders took part in a correlational study.

• Participants completed a questionnaire assessing their ACEs, ED symptoms, general functioning, and mental health.

Results:

• 36% of participants reported experiencing emotional neglect.

• Emotional abuse was independently associated with increased concerns about eating, body shape, and weight.

Conclusion:

• Different ACEs uniquely affect ED symptoms, with emotional abuse having the greatest impact on ED severity.

Sociocultural explanation → Adverse childhood experiences(ACEs) → Guillaume et al (2016) → Ev

G - Generalizability:

• The study includes 192 female participants with eating disorders, providing a relatively large sample, though it may not be generalizable to males or other populations.

R - Reliability:

• The study used self-reported questionnaires, which may introduce bias or inaccuracies in reporting. However, using standardized measures increases the reliability of the findings.

A - Applications:

• The findings highlight the significant role of emotional abuse in the development and severity of eating disorders, suggesting that targeted interventions focusing on childhood trauma could be effective in treating eating disorders.

V - Validity:

• The study uses a correlational design, which limits its ability to establish causal relationships. However, the focus on real-life ACEs and their effects on ED symptoms strengthens ecological validity.

E - Ethical considerations:

• Ethical concerns include the use of self-reporting questionnaires, which could evoke emotional distress in participants recalling adverse childhood experiences. However, the study likely ensured informed consent and participant anonymity.

Prevalence rates for Anorexia Nervosa

Prevalence Rates and Incidence

• Prevalence rate refers to the percentage of a population with a specific disorder. For anorexia nervosa (AN), the prevalence rate in the U.S. is between 1-4%.

• Point prevalence measures the percentage of the population with the disorder at a specific point in time. In the past three years, the point prevalence of AN in females is between 0.5% and 8.7%.

• Incidence rate refers to the number of new cases diagnosed in a certain time period. For AN, the incidence rate is 4% for females and 0.3% for males.

Factors Affecting Prevalence

• Underreporting and lack of diagnosis occur due to stigma, denial, or lack of awareness, leading to lower prevalence rates.

• Cultural norms around thinness and beauty standards, influenced by media or culture, can cause individuals to hide symptoms, skewing prevalence rates.

• Gender bias can lead to underdiagnosis in males due to stereotypes about eating disorders being primarily female. This affects gender-based prevalence rates.

• Cultural bias may cause misrecognition of symptoms based on differing cultural norms, leading to inaccurate prevalence data.

• Point prevalence does not account for individuals with fluctuating or relapsing cases of AN, which could result in missing data on recurring cases.

• Delayed help-seeking behavior may lead to misreported incidence rates, as those who delay treatment are less likely to be included in studies.

Evaluation of Factors Affecting Prevalence Rates

Underreporting and Lack of Diagnosis:

• Many individuals with Anorexia Nervosa (AN) do not seek help due to stigma, denial, or lack of awareness, leading to underreporting.

• Gender and cultural biases can result in males and certain cultural groups being misdiagnosed or underdiagnosed.

Impact of Sociocultural Norms:

• Cultural ideals, especially those promoted by media, can cause people to hide symptoms to fit societal standards, affecting prevalence rates.

• Adverse childhood experiences (ACEs) may trigger or worsen eating disorders, but lack of awareness can lead to underreporting.

Gender and Cultural Bias:

• Males are often underdiagnosed because eating disorders are stereotypically associated with females, distorting gender-based prevalence data.

• Cultural differences can influence how symptoms of eating disorders appear, complicating diagnosis and affecting recognition rates in some populations.

prevalence rates for Anorexia Nervosa → Forrest (2017)

Aim:

• Investigate the extent of underreporting in diagnostic procedures and its impact on clinical outcomes for eating disorders (EDs).

Method:

• Data from a nationally representative cross-sectional study of U.S. adolescents aged 13-18 years (N = 281) were analyzed.

• Sociodemographic information, ED characteristics, psychiatric comorbidities, and mental health service use were assessed via interview.

Results:

• Only 20% of adolescents sought treatment for EDs.

• Females were 2.2 times more likely to seek treatment than males.

• ED behaviors such as restriction and purging, as well as ED-related impairment, were associated with a higher likelihood of treatment-seeking

Conclusion:

• Underreporting in diagnostic procedures poses serious implications for patient safety and healthcare quality.

prevalence rates for Anorexia Nervosa → Forrest (2017) → Evaluation

• Generalisability: The study uses a nationally representative U.S. adolescent sample, making the findings broadly applicable to similar populations, but less so to other age groups or cultures.

• Reliability: Self-reported data and the cross-sectional design provide reliable insights, but causal relationships cannot be determined.

• Applications: The findings emphasize the importance of improving ED diagnosis and treatment-seeking behaviors, especially for males.

• Validity: Self-reporting may introduce biases, and the focus on adolescents limits the generalisability to other age groups.

• Ethics: The study adhered to ethical guidelines, though discussing sensitive ED issues could have impacted participants' well-being.

• Significance: It underlines the importance of addressing underreporting in ED diagnoses to improve patient care and early intervention.

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