Testing a Motor Score Based on PANSS Ratings: A Proxy for Comprehensive Motor Assessment

Area of Science:

• Psychiatry
• Neuroscience
• Clinical Psychology

Background:

• Abnormal psychomotor behavior is a key symptom of schizophrenia, but its assessment using expert scales is difficult.
• The Positive and Negative Syndrome Scale (PANSS) includes three items related to hypokinetic motor behavior.

Purpose of the Study:

• To evaluate if a sum score of specific PANSS items (mannerisms and posturing [G5], motor retardation [G7], and disturbance of volition [G13]), termed PANSS motor score (PANSSmot), can serve as a proxy for motor abnormalities.
• To assess the correlation of PANSSmot with expert motor rating scales and its ability to differentiate patient groups.

Main Methods:

• Combined baseline data from two clinical trials (n=196) to correlate PANSSmot with five motor rating scales.
• Investigated a cutoff of ≥3 on each PANSS motor item (total ≥9 on PANSSmot) to differentiate patients.
• Replicated findings in an independent trial (n=102) and assessed longitudinal stability and validity with physical activity measures.

Main Results:

• PANSSmot showed significant correlations with all tested motor scales (Spearman-Rho range 0.19-0.52, P≤0.007).
• The established cutoff successfully differentiated patients into high vs. low motor score groups across most scales, excluding the Abnormal Involuntary Movement Scale.

Conclusions:

• The PANSSmot score is a potential proxy measure for hypokinetic motor abnormalities in schizophrenia.
• This proxy measure may facilitate the analysis of large datasets to identify interventions for hypokinetic motor abnormalities in psychosis.