Spontaneous Dyskinesia: No Association with Familial Liability to Schizophrenia

1
Spontaneous Dyskinesia No Association with
Familial Liability to Schizophrenia Sarah I.
Tarbox, Anna Grippo, and Michael F. Pogue-Geile
Department of Psychology University of
Pittsburgh

• Method
• Participants
• Index probands schizophrenia/schizoaffective
  outpatients (medicated) (n51).
• Index siblings biological siblings of index
  probands (n 33).
• Controls healthy control probands and their
  biological siblings (combined) (n 55).
• Videotape Sampling
• 30-minute segments of videotaped clinical
  interviews were assessed.
• Coding was completed by a single rater who was
  blind to group and family status and obtained
  good reliability (r 0.61-0.91) with a second
  trained rater.
• All coding was done using The Observer Video-Pro
  5.0 computer program (Noldus, 2003).
• Spontaneous Dyskinesia Coding

• Summary
• Index siblings did not display significantly
  more involuntary movements compared to controls.
• Medicated schizophrenia patients displayed
  significantly more total spontaneous dyskinesia
  compared to non-psychotic siblings and controls.
• The following categories were elevated in
  patients vs. controls
• Akathisia right left arms, hands/fingers,
  and trunk
• Rest tremor left arm, and right left
  hands/fingers
• Intention tremor - right arm, right
  hand/fingers, and head
• Strengths Limitations
• Strengths
• Videotape assessment methodology.
• Computer assisted behavior ratings.

Results Demographics

• Rationale
• Previous findings suggest that spontaneous
  dyskinesia (spontaneous, involuntary movement
  abnormalities) exists in a substantial minority
  of neuroleptic naïve schizophrenia patients.
• In addition, some studies suggest that
  spontaneous dyskinesia may be present in the
  non-psychotic, first-degree relatives of
  schizophrenia patients.
• However, inconsistencies present in the
  literature to date indicate the need for further
  study.
• Aims
• To clarify the potential value of spontaneous
  dyskinesia as an endophenotype (Gottesman
  Shields, 1972) in genetic studies of
  schizophrenia by
• Investigating the existence of spontaneous
  dyskinesia in schizophrenia patients, their
  non-psychotic siblings, and controls.
• Improving measurement sensitivity and minimizing
  confounds (e.g., age, control group selection
  criteria) that currently exist in the literature.

Significant differences Index probands vs.
Controls age (p 0.004), sex (p 0.001), race
(p 0.035), alcohol/substance (p 0.001) Index
probands vs. Siblings sex (p 0.002),
alcohol/substance (p 0.023) Siblings vs.
Controls alcohol/substance (p 0.010)
Total Spontaneous Dyskinesia
Logistic regression results Index probands vs.
Controls p 0.001 Index probands vs. Siblings
p 0.001 Siblings vs. Controls p 0.227
Significant Movement Categories
Logistic regression results Index Probands vs.
Controls Akathesia p 0.001 Rest tremor
p 0.002 Intention tremor p
0.013 Index Probands vs. Siblings Akathesia p
0.002 Rest tremor p 0.021 Intention
tremor p 0.183 Siblings vs.
Controls Akathesia p 0.259 Rest tremor p
0.012 Intention tremor p 0.057
Significant following Bonferonni correction, p lt
0.007