What are first rank, second rank, and third rank symptoms in psychiatry, particularly in the diagnosis of schizophrenia?

First, Second, and Third Rank Symptoms in Psychiatry

The terminology of "first rank," "second rank," and "third rank" symptoms specifically refers to Kurt Schneider's hierarchical classification of psychotic symptoms in schizophrenia, where first rank symptoms (FRS) were historically considered pathognomonic for schizophrenia, though modern diagnostic systems have significantly de-emphasized their unique diagnostic value.

First Rank Symptoms (Schneider's FRS)

First rank symptoms represent specific psychotic phenomena that Schneider originally proposed as diagnostically definitive for schizophrenia when occurring in clear consciousness 1, 2:

Core FRS Categories

• Auditory hallucinations of specific types:

  • Voices commenting on the patient's actions
  • Voices arguing or discussing the patient in third person
  • Thought echo (hearing one's own thoughts spoken aloud) 1, 3

• Thought disorders involving self-boundaries:

  • Thought insertion (experiencing thoughts as being placed into one's mind by external forces)
  • Thought withdrawal (experiencing thoughts as being removed from one's mind)
  • Thought broadcasting (experiencing one's thoughts as being accessible to others) 1, 2

• Passivity phenomena (made experiences):

  • Made feelings, impulses, or volitional acts (experiencing emotions, drives, or actions as controlled by external forces)
  • Somatic passivity (experiencing bodily sensations as externally imposed) 1, 3

• Delusional perception:

  • A two-stage phenomenon where a normal perception is followed by a delusional interpretation of profound personal significance 1

Clinical Context and Limitations

• Diagnostic specificity concerns: While FRS show relatively high specificity for schizophrenia, their sensitivity is poor, meaning many schizophrenia patients do not exhibit FRS 1, 3

• Non-schizophrenic occurrence: FRS can appear in mood disorders with psychotic features, organic psychoses, and other conditions, particularly when consciousness is impaired 1, 3

• Modern diagnostic de-emphasis: DSM-5 has eliminated special status for FRS, treating them as equivalent to any other "criterion A" psychotic symptom, though ICD-10 still gives them prominence 1, 3

• Self-disorder as core feature: The underlying theme connecting FRS is disturbance of self-boundaries and self-experience, which may represent a phenotypic trait marker of schizophrenia 1

Second Rank Symptoms

Second rank symptoms represent psychotic phenomena that Schneider considered supportive but not pathognomonic of schizophrenia 2:

• Other types of hallucinations not meeting FRS criteria (visual, olfactory, tactile hallucinations)
• Simple delusions without the two-stage delusional perception structure
• Perplexity and confusion in the context of psychosis
• Mood changes occurring within psychotic episodes 2

These symptoms have less diagnostic weight than FRS but contribute to the overall clinical picture when present alongside other features.

Third Rank Symptoms

Third rank symptoms represent non-specific features that may occur in schizophrenia but lack diagnostic specificity 2:

• Emotional blunting and affective flattening
• Other negative symptoms including social withdrawal and avolition
• Nonspecific behavioral changes
• Personality changes that may occur in various psychiatric conditions 2

Modern Symptom Classification Framework

Contemporary diagnostic approaches have largely abandoned Schneider's rank system in favor of symptom domain classification 4, 5:

Positive Symptoms

• Hallucinations (most commonly auditory), delusions, disorganized speech, and grossly disorganized or catatonic behavior represent symptoms present in excess of normal functioning 4, 5

Negative Symptoms

• Avolition (decreased motivation), anhedonia (inability to experience pleasure), asociality (social withdrawal), blunted affect (reduced emotional expression), and alogia (poverty of speech) represent diminished normal functions 4, 5

Cognitive Symptoms

• Executive dysfunction, impaired information processing, attention deficits, and problems with planning and abstract thinking affect approximately 80% of schizophrenia patients 4

Clinical Utility and Practical Recommendations

In contemporary practice, the presence of FRS should raise diagnostic suspicion for schizophrenia but should not be considered sufficient alone for diagnosis 1, 3:

• When FRS are present: They support the diagnosis of schizophrenia when other diagnostic criteria are met, and they may be particularly useful for differentiating schizophrenia from organic causes of psychosis in resource-limited settings 1

• When FRS are absent: Their absence should prompt careful consideration of alternative diagnoses, particularly mood disorders, neurological conditions, and other somatic causes of psychosis 1

• Assessment requirements: Proper identification of FRS requires careful phenomenological assessment in clear consciousness, as symptoms occurring during delirium or acute intoxication lack diagnostic specificity 1, 3

• Prognostic implications: Evidence regarding FRS and prognosis is mixed, with some studies suggesting association with more chronic course, though this remains controversial 2, 6