Classification & Diagnosis of phobias

Classification & Diagnosis of phobias

1. Clinical characteristics

   • Diagnosis
     • Fear persistent & excessive
     • Phobic stimulus causes an immediate response
     • Individual is aware their fear is irrational
     • Phobia interferes with daily life
     • Phobia has existed for more than 6 months
   • DSM & ICD used for classification
     • 3 types of phobia
       • Specific phobia - fear of an object
       • Social phobia - fear of a social situation
       • Agoraphobia - fear of situations where escape may be difficult/open spaces

2. Reliability

   • Reliability - the consistency of a measuring instrument
   • Inter-rater reliability - how consistent different clinicians diagnosis is
     • Skyre et al - three clinicians assessed 54 patients using the Structured Clinical Interview (SCID-I) Inter-rater agreement +.72
       • semi-structured interview - extensive training
     • Kendler et al - low retest reliability due to poor recall or exaggeration of fears
       • May also be due to different clinicians seeing different things as significant
   • Test-retest reliability - used to check external reliability. Same test given on different occasions
     • Hiller et al - satisfactory - exellent diagnosis agreement in test-retest using Munich Diagnostic Checklist (MDC)

3. Validity

   • Validity - extent that a diagnosis represents something real & distinct
     • Research requires high validity assessment methods else the findings will have low validity
   • Comorbidity decreases usefulness of diagnostic categories
     • Kendler et al - high comorbidity between social phobias & animal phobias
     • Eyesenk - up to 66% diagnosed with one anxiety disorder have another
   • Concurrent validity - measures the validity of a classification method comparing it to an existing one
     • Taijn-kyofusho (TKS) Japanese phobia of embarrassing someone in public. Not a British phobia. Cultural differences
   • Construct validity - sees if individuals with key behaviours are diagnosed as phobic
     • Someone with social phobia underestimates their social ability