The Diagnostic and Statistical Manual of Mental Disorders (DSM) is the primary resource used by healthcare professionals in the United States for diagnosing mental health conditions. Published by the American Psychiatric Association (APA), the DSM has evolved through several editions to reflect the latest understanding in the field. Notably, the DSM-IV, the fourth edition, utilized a multi-axial system which included five distinct axes to provide a comprehensive diagnostic picture. This system was a significant part of psychiatric diagnosis for many years before being discontinued in the DSM-5.
One crucial component of the DSM-IV’s multi-axial system was Axis II. This axis specifically focused on personality disorders and mental retardation, now termed intellectual development disorder. Understanding Axis II is key to grasping the older diagnostic framework and how it considered long-standing patterns of behavior and developmental conditions alongside acute mental health issues.
:max_bytes(150000):strip_icc()/five-axes-of-the-dsm-iv-multi-axial-system-1067053_final-de64cd6b001f472f86ec6ed5b226ad3f.png)
The Multi-Axial System: A Historical Perspective
Introduced in the DSM-III, the multi-axial system was designed to provide clinicians with a structured approach to diagnosis. It aimed to capture a wider range of information beyond just the primary clinical disorder. By using multiple axes, clinicians could record different facets of a patient’s condition, including clinical disorders, personality disorders, medical conditions, psychosocial stressors, and overall functioning.
Before the DSM-5, a diagnosis wasn’t simply a single label. It was a multi-faceted assessment across these five axes. For instance, an individual diagnosed with Major Depressive Disorder (Axis I) would also be evaluated on other axes. Axis II would identify any co-occurring personality disorders, Axis III would note relevant medical conditions, Axis IV would detail psychosocial and environmental problems, and Axis V would provide a Global Assessment of Functioning (GAF) score.
However, the APA, after careful consideration and recognizing the lack of strong empirical evidence supporting this division, moved away from the multi-axial system with the release of the DSM-5 in 2013. The rationale was that the distinctions between axes were not always scientifically valid and could sometimes lead to confusion rather than clarity.
The Purpose of Axis II: Delving into Personality Disorders and Intellectual Disability
Axis II of the DSM-IV served a very specific purpose: to highlight enduring, pervasive conditions that significantly impact an individual’s functioning and are often present from early adulthood. It was dedicated to listing personality disorders and mental retardation.
Personality disorders are characterized by inflexible and unhealthy personality traits that cause significant problems in a person’s life and relationships. These are not simply phases or reactions to stress; they are ingrained patterns of thinking, feeling, and behaving. Mental retardation, now intellectual development disorder, refers to significant limitations in both intellectual functioning and adaptive behavior, originating before the age of 18.
By placing these conditions on a separate axis, the DSM-IV emphasized their chronic nature and their potential influence on the presentation and treatment of Axis I disorders. It ensured that clinicians considered these long-term patterns when diagnosing and planning treatment.
Axis II Diagnosis List: Categories and Examples
The DSM-IV Axis II included a specific list of personality disorders, categorized into three clusters (A, B, and C) based on descriptive similarities. It also included Mental Retardation. Here’s a breakdown of the diagnoses that comprised the Axis II diagnosis list:
Cluster A: Odd or Eccentric Disorders
- Paranoid Personality Disorder: Characterized by distrust and suspiciousness of others, interpreting motives as malevolent.
- Schizoid Personality Disorder: Characterized by detachment from social relationships and restricted range of emotional expression.
- Schizotypal Personality Disorder: Characterized by acute discomfort in close relationships, cognitive or perceptual distortions, and eccentricities of behavior.
Cluster B: Dramatic, Emotional, or Erratic Disorders
- Antisocial Personality Disorder: Characterized by disregard for and violation of the rights of others.
- Borderline Personality Disorder: Characterized by instability in interpersonal relationships, self-image, and affects, and marked impulsivity.
- Histrionic Personality Disorder: Characterized by excessive emotionality and attention seeking.
- Narcissistic Personality Disorder: Characterized by grandiosity, need for admiration, and lack of empathy.
Cluster C: Anxious or Fearful Disorders
- Avoidant Personality Disorder: Characterized by social inhibition, feelings of inadequacy, and hypersensitivity to negative evaluation.
- Dependent Personality Disorder: Characterized by excessive need to be taken care of that leads to submissive and clinging behavior and fears of separation.
- Obsessive-Compulsive Personality Disorder: Characterized by preoccupation with orderliness, perfectionism, and control.
- Personality Disorder Not Otherwise Specified: This category was used when an individual presented with personality disturbance that did not meet the criteria for any specific personality disorder.
Intellectual Retardation (now Intellectual Development Disorder)
- This encompassed individuals with significantly subaverage intellectual functioning accompanied by deficits in adaptive functioning, with onset before age 18. The DSM-IV further categorized mental retardation by severity (mild, moderate, severe, profound) based on IQ scores.
Changes from DSM-IV to DSM-5: The Non-Axial System
With the transition to the DSM-5, the multi-axial system was eliminated. The APA concluded that the distinct axes were not always clinically useful and could be artificial separations. The DSM-5 adopted a non-axial system, combining Axes I, II, and III into a single diagnostic listing. Information that would have been coded on Axes IV and V is now incorporated as separate “V codes” or through narrative descriptions of psychosocial and contextual factors.
Specifically for Axis II, personality disorders and intellectual development disorder are still recognized and diagnosed in DSM-5, but they are no longer separated onto a distinct axis. They are listed alongside other mental disorders. Mental Retardation was renamed to Intellectual Disability in DSM-5, and further updated to Intellectual Development Disorder in the DSM-5-TR (text revision), with Intellectual Disability remaining in parentheses for continuity.
This change reflects a move towards a more streamlined and less compartmentalized approach to diagnosis, recognizing the interconnectedness of mental health conditions, personality traits, and general medical conditions.
Why the Shift Away from the Multi-Axial System?
Several factors contributed to the discontinuation of the multi-axial system. One major concern was the artificial separation between Axis I and Axis II disorders. Clinicians and researchers questioned the validity of categorizing certain conditions as acute (Axis I) and others as chronic personality patterns (Axis II), as comorbidity was common and the distinction could be blurry.
Furthermore, the Global Assessment of Functioning (GAF) from Axis V was criticized for its lack of sensitivity to specific areas of impairment and for not adequately capturing important factors like suicide risk.
Ultimately, the APA aimed for a diagnostic system that was simpler to use, more clinically relevant, and better reflected the current scientific understanding of mental disorders. The non-axial approach in DSM-5 is intended to achieve this by integrating all relevant diagnostic information into a more cohesive and less fragmented framework.
Conclusion: Understanding Axis II in Context
While the DSM-IV multi-axial system, including Axis II and its diagnosis list, is no longer in current clinical practice, understanding its historical significance is valuable. Axis II played a crucial role in emphasizing the importance of considering personality disorders and intellectual disability alongside other mental health conditions. It highlighted the need to assess enduring patterns of behavior and developmental factors in a comprehensive diagnostic evaluation.
Today, although the structure has changed, the conditions previously listed under Axis II—personality disorders and intellectual development disorder—remain important diagnostic categories within the DSM-5 and DSM-5-TR. Understanding the legacy of Axis II helps appreciate the evolution of diagnostic approaches in mental health and the ongoing effort to create systems that are both clinically useful and scientifically sound.
