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A crucial issue in psychiatry and criminology is how to correctly diagnose personality disorders in people who have committed crimes. It’s not as simple as saying that a criminal record automatically equals a diagnosis of Antisocial Personality Disorder (ASPD).

This is far more than an academic debate; it has serious real-world consequences. A person’s diagnosis can affect their legal position, their access to psychological services, and even how the public views them. The two main diagnostic manuals, the World Health Organisation’s International Classification of Diseases, 10th revision (ICD-10) and the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, 5th edition, Text Revision (DSM-5-TR), have different approaches to this challenge.

This article explores these differences, arguing that while the DSM-5-TR’s rules are more specific to criminal behaviour, its rigid requirement for a history of conduct disorder can actually make the diagnosis less likely in certain forensic populations compared to the more cautious, yet flexible, approach of the ICD-10.

The Careful Approach of ICD-10

The ICD-10’s framework for personality disorders (F60) is notably cautious. It sets out a number of general rules that have to be met for a diagnosis of any personality disorder, including what it calls ‘Dissocial Personality Disorder’ (F60.2), the ICD-10 equivalent of ASPD.

Crucially, the ICD-10 says the problems must not be a direct result of another psychiatric disorder, organic brain disease, or substance use. This is a fundamental step, a way of ruling out a wide range of other causes that applies across the F60 category. This means a doctor using the ICD-10 has to first figure out if the behaviour can be better explained by a pre-existing condition like schizophrenia or a substance use problem. This tiered approach puts a higher priority on finding the main diagnosis and can lead to a lower number of co-occurring personality disorder diagnoses in complicated cases.

The DSM-5-TR’s Focus on Specific Conduct

By contrast, the DSM-5-TR’s approach to ASPD is more like a strict list of symptoms. The criteria for ASPD have a strong and clear focus on specific behaviours, with one rule about “Failure to conform to social norms with respect to lawful behaviours.” This makes a criminal history a key part of the diagnosis, which is different from the ICD-10’s broader behavioural descriptions.

The DSM-5-TR also includes an exclusion rule, but it is much more specific than the ICD-10’s general rule. It states that the antisocial behaviour must not happen exclusively during schizophrenia or bipolar disorder. This leaves more room for a person to be diagnosed with both ASPD and another disorder.

However, the most significant difference lies in the DSM-5-TR’s specific and mandatory requirement for a history of Conduct Disorder with onset before the age of 15. This isn’t a general rule for all personality disorders but a unique filter for ASPD.

How the ‘Before 15’ Rule Acts as a Filter

The DSM-5-TR’s rule about early-onset Conduct Disorder functions differently than a classical exclusion criterion. While that kind of rule would prevent a diagnosis, this is a required condition that must be met for the diagnosis to be made. It effectively excludes anyone whose antisocial behaviour, no matter how severe or persistent, began after their fifteenth birthday. This means that a person with a significant criminal career that started in late adolescence or early adulthood, a common situation in forensic settings, would be automatically excluded from an ASPD diagnosis under the DSM-5-TR.

This shows a fundamental difference in how the two manuals view what causes the disorder. The DSM-5-TR sees ASPD as a problem that starts in childhood and continues over time. The ICD-10, while acknowledging the early onset of personality disorders, uses a more flexible description: the patterns must begin in “childhood or adolescence.” This allows for more clinical judgement, and a doctor may interpret a behavioural pattern beginning at 16 or 17 as still falling within the definition of adolescence.

The Enduring Legacy of Caution in ICD-11

The careful approach of ICD-10 is carried forward into its successor, the ICD-11, though it’s within a completely new way of diagnosing things. The ICD-11 gets rid of the ten specific personality disorder types from the ICD-10 and instead uses one diagnosis that uses a scale, ‘Personality Disorder’. The diagnosis is now based on a full picture of how severe the dysfunction is in a person’s life and relationships (from ‘Personality Difficulty’ to ‘Severe Personality Disorder’), with optional ‘trait specifiers’ to describe key features.

Despite this change, the spirit of the ICD-10’s cautious approach remains. Firstly, the rules for ruling out other causes are still in place. The ICD-11 explicitly states that a personality disorder diagnosis cannot be given if the symptoms are a direct result of another psychiatric disorder, organic brain disease, or substance use. This directly continues the logical progression of the F60 general criteria.

Secondly, the developmental perspective is still descriptive rather than rigid. Like the ICD-10, the ICD-11 notes that personality disorders generally start in childhood or adolescence and are stable over time, but it avoids the strict age cut-offs seen in the DSM-5-TR. This keeps the doctor’s flexibility and avoids automatically excluding people whose problematic patterns began a little later.

Furthermore, the ICD-11’s focus on severity as a central part of the diagnosis is in itself a careful measure. It moves the focus away from a symptom checklist to a more complete assessment of the person’s overall impairment. The key question for diagnosis is about how deeply the symptoms are affecting a person’s life, which is a more considered and clinically useful approach.

Conclusion

The different frameworks of the ICD-10 and DSM-5-TR lead to different diagnostic outcomes.

The ICD-10’s broad, foundational exclusion rules for all personality disorders require a more cautious, tiered approach that may limit diagnoses in individuals with complex co-morbidities. Conversely, the DSM-5-TR’s criteria for ASPD are more specific to the behaviours that lead to crime and have a rigid developmental timeline.

While the ICD-10’s ‘Dissocial Personality Disorder’ is defined by a general pattern of disregard for social norms and others’ rights, the DSM-5-TR’s ASPD diagnosis is tied directly to both criminal behaviour and a specific history of Conduct Disorder.

Therefore, a greater proportion of people with long-standing criminal careers are indeed likely to meet the DSM-5-TR’s criteria, precisely because its focus is on behaviours relevant to forensic populations and its more specific, yet less broad, exclusionary rules. These differences aren’t just small academic points but have major real-world consequences for diagnosis, how often the disorder is found, and, ultimately, the treatment options available to individuals within the legal and psychiatric systems.