What is a mental disorder? An exemplar-focused approach

Area of Science:

• Philosophy of Psychiatry
• Psychiatric Nosology
• Clinical Psychology

Background:

• The definition of mental disorder is a core philosophical and practical issue in psychiatry.
• Previous diagnostic manuals like the DSM-5 have faced challenges with classifying certain conditions.
• A clear definition is needed for consistent diagnosis and treatment.

Purpose of the Study:

• To develop practical guidelines for evaluating future proposals for new mental disorder classifications.
• To analyze problematic case examples from the DSM-5 revision process.
• To inform the ongoing debate on the criteria for defining mental disorders.

Main Methods:

• Review of exemplar cases with ambiguous harm/dysfunction criteria.
• Analysis of real-world problematic cases emerging during and after DSM-5 development.
• Qualitative assessment of practical judgment in psychiatric nosology.

Main Results:

• No universal criteria were found to accept or reject new mental disorder proposals.
• Case examples highlighted the need to consider individual versus societal harm and accommodation.
• Sharper indicators for dysfunction and clearer data requirements for diagnostic validity and clinical utility are needed.

Conclusions:

• Future mental disorder proposals require case-by-case evaluation using practical judgment.
• Refining the concepts of harm and dysfunction is crucial for accurate psychiatric nosology.
• Integrating diagnostic validity and clinical utility evidence will improve mental disorder definitions.