What are the changes in diagnosis of bipolar and related disorders due to another medical condition across Diagnostic and Statistical Manual of Mental Disorders (DSM) 3, 4, 5, and 5-Text Revision (TR), and International Classification of Diseases (ICD) 10 and 11?

Evolution of Bipolar and Related Disorder Due to Another Medical Condition Across DSM and ICD Classifications

Direct Answer

The specific diagnostic category "bipolar and related disorder due to another medical condition" has undergone minimal explicit changes across DSM-3, DSM-4, DSM-5, and DSM-5-TR, as this represents a secondary bipolar syndrome attributed to a general medical condition that has remained conceptually stable; however, the broader bipolar disorder classification has evolved substantially, with ICD-11 and DSM-5/DSM-5-TR achieving greater harmonization by both requiring increased activity or energy alongside mood changes for hypo/manic episodes, while ICD-11 retains mixed episodes (eliminated in DSM-5) and maintains a more dimensional approach to symptom assessment. 1, 2

Key Diagnostic Requirement Changes Affecting All Bipolar Diagnoses (Including Medical Condition-Related)

The Activity/Energy Criterion Revolution

• Both DSM-5/DSM-5-TR and ICD-11 now require increased activity or energy in addition to mood elevation or irritability for diagnosing hypomania and mania, representing the most significant convergence point between classification systems 3, 1
• This additional requirement creates a more restrictive threshold for hypo/manic episode diagnosis, directly impacting how bipolar disorder due to medical conditions is identified 1
• The 4-day minimum duration for hypomanic episodes is maintained in ICD-11, with emphasis on dimensional symptom assessment and severity ratings 3

Mixed State Conceptualization: A Major Divergence

• ICD-11 retained the category of mixed episodes, while DSM-5 eliminated mixed episodes entirely, replacing them with a "mixed features" specifier that can be applied to manic, hypomanic, or depressive episodes 2
• The ICD-11 concept of mixed episodes appears more inclusive than the DSM-5 approach, though neither is perfect 2
• This divergence directly affects how clinicians diagnose bipolar disorder due to medical conditions when patients present with simultaneous manic and depressive features 2

Structural Classification Changes

ICD Evolution (ICD-10 to ICD-11)

• ICD-11 underwent the largest participative revision in classification history, expanding from 11 to 21 disorder groupings in the mental, behavioral, and neurodevelopmental disorders chapter 4
• Field studies demonstrated higher reliability and clinical utility compared to ICD-10, with 82.5% to 83.9% of clinicians rating ICD-11 as quite or extremely easy to use 3, 4
• ICD-11 provides explicit guidance on distinguishing bipolar symptoms from similar behavioral features in other conditions, including delirium and factitious disorder 4

DSM Evolution (DSM-3 Through DSM-5-TR)

• DSM-5 introduced dimensional parameters to assess symptoms and sub-threshold states in the bipolar spectrum, moving beyond purely categorical diagnosis 1
• New course specifiers such as mixed symptoms were added, while the mixed episode diagnosis was eliminated 1
• DSM-5-TR maintains DSM-5's core diagnostic framework while providing updated text and clarifications 3

Bipolar II Disorder Recognition: A Critical Harmonization

• Both DSM-5-TR and ICD-11 recognize Bipolar II disorder as a distinct diagnostic category, requiring at least one hypomanic episode and one major depressive episode with no history of mania 3
• ICD-11's inclusion of Bipolar II disorder represents a major advancement from ICD-10, improving harmonization with DSM-5 1
• ICD-11 allows for more nuanced characterization of depressive episodes compared to DSM-5-TR 3

Depressive Episode Criteria: Substantial ICD-11 Differences

• ICD-11's definition of depressive episodes is substantially different from DSM-5, but the lack of empirical support for these changes means the reliability and utility of bipolar depression diagnosis remain relatively low 2
• ICD-11 likely maintains bereavement as an exclusion criterion for depressive episodes, while DSM-5 removed this exclusion 1
• These differences directly impact the diagnosis of bipolar disorder due to medical conditions when depressive episodes are present 2

Dimensional vs. Categorical Approaches

Persistent Categorical Framework

• Both DSM-5-TR and ICD-11 remain primarily categorical, classifying mental phenomena based on self-reported or clinically observable symptoms rather than incorporating neurobiological dimensions 4
• Changes from ICD-10 to ICD-11 were relatively modest, with no paradigm shift toward biologically informed classification 4
• Neither system adequately addresses biological heterogeneity within diagnostic categories 4

Dimensional Enhancements

• ICD-11 emphasizes dimensional symptom assessment and severity ratings more than previous versions 3
• DSM-5 introduced dimensional parameters for assessing symptoms and sub-threshold bipolar spectrum states 1

Clinical Utility and Implementation Challenges

Reliability Data

• Initial results on ICD-11's reliability and clinical utility for bipolar disorders are promising but show only modest improvements, with newly created diagnostic categories having some limitations 3, 2
• Field studies may have selection bias, with practitioners positive toward ICD-11 more likely to participate 4
• Vignette-based studies describe prototypic cases that may not reflect real-life complexity 4

Ongoing Harmonization Needs

• Since DSM-5 was published before ICD-11 was finalized, ongoing changes in DSM-5.1 or future revisions will be necessary to improve harmonization of psychiatric diagnoses 1
• The focus should now be on facing challenges of implementation, dissemination, and education in using these guidelines 2
• Further ecological field studies are needed to reveal how well ICD-11 works under regular clinical conditions 4

Critical Pitfalls When Diagnosing Bipolar Disorder Due to Medical Conditions

• Clinicians must now verify the presence of increased activity or energy, not just mood changes, when attributing bipolar symptoms to a medical condition 3, 1
• The choice between using "mixed features" specifier (DSM-5-TR) versus "mixed episode" diagnosis (ICD-11) significantly impacts coding and treatment planning when medical conditions are involved 2
• The more restrictive threshold for hypo/mania may result in under-diagnosis of bipolar disorder secondary to medical conditions if the activity/energy criterion is not carefully assessed 1