DSM Foundations
Before studying individual disorders, start here: what DSM is for, how it is organized, and how psychologists reason with diagnostic information.
Foundational concepts
- Differential diagnosis
- The structured process of distinguishing a condition from other conditions that present with similar features, by systematically weighing which explanation best accounts for the full pattern of evidence.
- Comorbidity
- The co-occurrence of two or more distinct conditions in the same person at the same time, which is common in mental health and complicates both diagnosis and treatment planning.
- Specifiers
- Additional descriptors attached to a diagnosis that communicate more precise information -- such as severity, course, or particular symptom features -- without changing the core diagnosis itself.
- Categorical vs. dimensional thinking
- Two contrasting approaches to classification: categorical models sort presentations into distinct present/absent diagnoses, while dimensional models represent symptoms as existing along a continuum of severity.
- Clinical significance (distress or impairment)
- The requirement that symptoms cause meaningful distress or interfere with functioning in order to be considered part of a disorder, distinguishing ordinary human variation from a diagnosable condition.
- Cultural considerations in diagnosis
- The practice of interpreting symptoms and distress within a person's cultural context, since the expression, meaning, and acceptability of psychological experiences vary meaningfully across cultures.
- Reliability and validity in classification
- Reliability refers to whether a diagnosis is applied consistently across clinicians and occasions; validity refers to whether the diagnostic category actually captures a coherent, meaningful clinical phenomenon.