Consistency of diagnostic thresholds in DSM-V

Area of Science:

• Psychiatry
• Mental Health Research
• Epidemiology

Background:

• Diagnostic criteria in the Diagnostic and Statistical Manual of Mental Disorders (DSM) define symptom thresholds for mental health diagnoses.
• The 1997 Australian Survey of Mental Health and Wellbeing provides data on mental disorders and their impact.

Purpose of the Study:

• To investigate the levels of distress and disability associated with six internalizing disorders based on DSM-IV criteria.
• To evaluate whether current diagnostic thresholds adequately capture clinically significant distress and disability.

Main Methods:

• Utilized data from the 1997 Australian Survey of Mental Health and Wellbeing.
• Assessed distress using the K-10 and disability using the SF-12 Mental Component Summary (MCS).
• Compared distress and disability scores of individuals diagnosed with major depressive disorder, dysthymia, generalized anxiety disorder, social phobia, post-traumatic stress disorder, and obsessive-compulsive disorder against a 'well' population mean.

Main Results:

• Over 90% of individuals with dysthymia, major depressive disorder, generalized anxiety disorder, and post-traumatic stress disorder reported higher distress or disability than the well population mean.
• A majority of these individuals experienced severe distress or disability (more than 2 standard deviations above the mean).
• For social phobia and obsessive-compulsive disorder, a significant percentage (9-26%, rising to 16-40% without clinical significance criteria) scored below the well population mean, indicating minimal distress or disability.

Conclusions:

• The diagnostic thresholds for social phobia and obsessive-compulsive disorder appear less stringent than those for other internalizing disorders.
• Revision of these diagnostic thresholds is suggested for the upcoming DSM-V to better align with clinical significance.