Draft:Harmful Dysfunction Analysis

Harmful Dysfunction Analysis

Harmful dysfunction analysis (HDA) is a theoretical framework developed by American philosopher and clinical social worker Jerome C. Wakefield to define mental disorder. Bringing together evolutionary theory, philosophy, and clinical practice, Wakefield proposes that mental disorder is best thought of as a “harmful dysfunction”. Specifically, HDA suggests that a condition is a mental disorder only if it results from the failure of an internal mechanism to perform its natural evolutionary purpose (dysfunction) and results in effects considered harmful within a particular society (harm).

Background and Critique of Existing Models

Wakefield developed HDA in response to what he saw as persistent confusion in how psychiatry defines mental disorder. He was critical of the DSM-III-R, which described mental disorder as “statistically unexpectable distress or disability.” Although intended to improve diagnostic consistency across clinicians, Wakefield argued that the definition failed to meaningfully distinguish disorders from non-disorders and lacked a solid grounding in biological theory.

Historically, diagnostic approaches in psychiatry have often followed two broad traditions. The earlier approach was to base diagnosis on social deviance. Traits and behaviours deemed unacceptable, such as dissenting political views or minority sexual orientations, would be pathologised not because they reflected any underlying dysfunction, but simply because they were socially disapproved. Wakefield criticised this approach for its failure to differentiate mental disorder from behaviours that simply go against social expectations.

To avoid cultural bias, another approach was to define mental disorder in terms of statistical deviation. Conditions were classified as disordered if they fell significantly outside the average range of psychological measures. This is reflected in past diagnostic criteria for intellectual disability, which relied on low IQ scores, and in frameworks like Christopher Boorse’s biostatistical theory, which defines disorders as statistical deviations from typical functioning. Although this method appears more objective, Wakefield argued that it wrongly equates statistical rarity with disorder. As he explains, “excellence in strength, intelligence, energy, talent, or any other area is just as statistically deviant as its opposite.” Conversely, many conditions like the common cold are recognised as disorders despite their prevalence. A condition's frequency alone, he maintained, cannot reliably determine if it is a disorder.

HDA sought to correct these issues by requiring both dysfunction and harm.

Theoretical Components

Defining Harm

“‘Harmful’ is a value term, referring to conditions judged negative by sociocultural standards.”

In the context of HDA, harm refers to negative consequences experienced as a direct result of dysfunction. Importantly, whether something is harmful depends on the person's cultural environment, as societal norms determine which conditions are considered disadvantageous.

Wakefield originally proposed that ‘harm’ be interpreted broadly, encompassing any condition viewed negatively within a particular culture. More recently, he has clarified that for a condition to count as harmful, the negative consequences must be directly caused by the dysfunction. As a result, social stigma alone is an insufficient basis for harm.

Defining Dysfunction

“A failure of some internal mechanism to perform a function for which it was biologically designed.”

Dysfunction means a system's inability to serve the purpose it evolved for. This idea draws on natural selection, which explains that the traits present in living organisms emerged because they contributed to survival and reproductive success.

Disorder as a Hybrid Concept

Venn Diagram Illustrating HDA

HDA holds that both harm and dysfunction must be present for a condition to be a mental disorder. Dysfunction provides the objective basis for diagnosis; harm adds cultural sensitivity. Thus, not all dysfunctions are mental disorders, and not every harmful condition is a mental disorder.

An example Wakefield uses to illustrate this is dyslexia. Dyslexia is a failure of the brain's language-processing system and, therefore, a dysfunction. However, whether it is considered a mental disorder depends on the cultural context. In a literate society, where reading is indispensable to daily life, dyslexia causes clear disadvantages, making it a disorder. In a pre-literate society where reading is not a necessary skill, it would cause no harm and not be viewed as a disorder. Wakefield describes such cases as “harmless dysfunctions": biological failures that do not produce socially meaningful problems. Wakefield also highlights other conditions like criminality and illiteracy, which are harmful but do not stem from dysfunction. They illustrate that harm alone is insufficient.

Criticisms

On Dysfunction

Critics of the dysfunction requirement argue that identifying the evolved functions of complex mental mechanisms is often difficult, if not impossible. Many mental functions may have arisen as by-products of other adaptations or evolved to serve multiple purposes, making it challenging to pinpoint a clearly ‘designed’ function.

Philosopher Maël Lemoine questioned whether the dysfunction component is genuinely value-free, suggesting it inherently involves interpretive assumptions, not just description. Further, Justin Garson uses developmental plasticity, the capacity to develop different traits in response to early environments, to challenge the dysfunction requirement of HDA. He argues that this adaptability can lead to "mismatches", where traits that were once beneficial in childhood become harmful later in life. These cases, he suggests, result in genuine mental disorders without technically involving dysfunctions.

On Harm

The harm component has also attracted criticism, particularly regarding its reliance on social values. Rachel Cooper has argued that while the harm concept is necessary to prevent the medicalisation of oddities, it remains vague. She finds Wakefield's definition broad and that the concept needs further clarification.

Furthermore, Andreas De Block and Jonathan Sholl question whether harm should be determined through social values or individual experience. They argue that both approaches present problems. If harm depends on local social norms, the concept becomes vulnerable to culturally biased conclusions. For example, it could justify labelling homosexuality a disorder in heteronormative societies if it is also assumed to involve dysfunction. Alternatively, basing harm on an individual's subjective experience would encourage diagnostic inconsistencies, as some individuals with severe disorders may not perceive themselves as harmed. In either case, they conclude that the harm requirement introduces enough subjectivity to undermine HDA's goal of offering a coherent definition of mental disorder. Additionally, they argue that Wakefield implicitly uses harm to identify dysfunction, thereby 'smuggling' the value component into the supposedly factual one. As a result, the two concepts do not seem truly independent as Wakefield suggests.

Alternative Models

Notably, Christopher Boorse continues to defend his biostatistical theory of mental disorder. Boorse argues his model avoids the ambiguities associated with cultural judgements. He also contends that HDA conflicts with actual medical practice regarding ‘harmless dysfunctions’. He notes that many such conditions are nonetheless recognised as disorders in clinical settings, raising concerns about HDA’s legitimacy. Lemoine has also proposed a 'Harmful Abnormality Analysis' as an alternative.