. 2006 Nov 8;33(4):1038–1053. doi: 10.1093/schbul/sbl051

Table 2.

Overview of Studies Addressing PS in Schizophrenia

Study	Sample (n)	Mean Age	Inpatient/Outpatient	Medication	Psychomotor Task	Main Findings
Caligiuri et al¹²⁰	Neuroleptic-naive schizophrenic patients (24)	42.2	14 inpatients and 10 outpatients	/	Wrist rotation	12% of neuroleptic-naive schizophrenic patients had bradykinesia compared with none of the healthy controls.
Caligiuri et al¹²⁰	Healthy controls (24)	42.2	14 inpatients and 10 outpatients	/	Wrist rotation
Carnahan et al¹²¹	Schizophrenics (12)	29.3	?	Antipsychotics	Fitts' task with mouse on graphics tablet	Relative to the healthy controls, the patients exhibited a movement-planning deficit without a decrement in movement execution. The patients still performed according to Fitts' law, which states that in aiming movement time decreases as target distance decreases and target size increases.
Carnahan et al¹²¹	Healthy controls (12)	26.1	?	Antipsychotics	Fitts' task with mouse on graphics tablet
Fuller and Jahanshahi³³	Schizophrenics (11)	38.5	Outpatients	Antipsychotics	Purdue pegboard task and FTT	Patients were slower than the controls in both tasks in the unimanual but not in the bimanual condition. Peg placing was less slowed when performing a secondary task with the other hand. Pegboard and FTT performance significantly correlated with negative symptoms.
Fuller and Jahanshahi³³	Controls (13)	38.15	Outpatients	Antipsychotics	Purdue pegboard task and FTT
Gallucci et al¹²²	Schizophrenics (20)	31.1	?	2 unmedicated, 12 AAP, 6 CNL, and 4 anticholinergics	Handwriting movements recorded with graphics tablet	Handwriting in patients was not slowed but less efficient and consistent with a trend toward macrographic strokes.
Gallucci et al¹²²	Matched controls		?	2 unmedicated, 12 AAP, 6 CNL, and 4 anticholinergics	Handwriting movements recorded with graphics tablet
Henkel et al³⁵	Schizophrenics (16)	35.1	Inpatients	Test-retest: drug-free vs haloperidol (mean dose: 10.4 mg) and anticholinergics (n = 6)	Drawing of circles and writing of sentences on writing tablet	Performance of neuroleptic-free patients was slower. Slowing was associated with negative symptoms. Amelioration of negative symptoms under haloperidol treatment was significantly associated with speeding-up of handwriting.
Henkel et al³⁵	Healthy controls (16)		Inpatients
Holthausen et al⁵⁴	Schizophrenics (32)	24.8	?	Average dose: 6.1 mg haloperidol equivalents, 7 drug-free patients, and 15 on anticholinergics	FTT	FTT correlated with the depressive and the negative symptom dimension.
	Schizophreniform (10)	23.7
	Delusional disorder (2)	28.5
	Brief psychotic disorder (2)	18.0
	Psychotic disorder NOS (4)	31.8
Jogems-Kosterman et al³⁸	Schizophrenia (19)	37.0	14 outpatients	Antipsychotics (mean dosage 7.6 mg haloperidol equivalents)	Line-copying task, complex-figure copying task recorded on writing tablet	Patients' movement initiation and execution was slowed. Overall, patients were one-third slower than the controls. Initiation time latencies with increasing complexity were significantly higher in the subgroup with higher negative symptoms. Increased reinspection times demonstrated affected planning strategy.
Jogems-Kosterman et al³⁸	Controls (19)	37.5	14 outpatients	Antipsychotics (mean dosage 7.6 mg haloperidol equivalents)
Malla et al³⁶	Schizophrenics (21)	29.0	?	Antipsychotics	Fitts' task with mouse on graphics tablet	Weak correlations between psychomotor poverty and RTs and no correlations with movement times. Strong associations between RT and disorganization syndrome.
Mohamed et al¹²³	First-episode schizophrenics (94)	26.1	Inclusion after admission	73 neuroleptic-naive patients, 14 receiving antipsychotics for less than a week, 7 for less than 2 wk	FTT	Impairments in speeded cognitive tasks with (SDST, and TMT) and without (Stroop) motor component. Patients performed relatively better on the FTT, leading the authors to conclude that poor performance on speeded tasks reflects bradyphrenia rather than bradykinesia.
Mohamed et al¹²³	Normal controls (305)	25.5	Inclusion after admission		FTT
Morrens et al³⁹	Schizophrenics (30)	27.5	Inpatients	Atypical antipsychotics (22), conventional neuroleptics (7), and other psychotropics	SDST on graphics tablet	Both matching time (initiation) and writing time (execution) on SDST were slowed but unassociated. Matching time, reflecting slowing in higher order cognitive processes, but not writing time, reflecting PS, proved associated with other neuropsychological measures.
Morrens et al³⁹	Controls (30)	33.0	Inpatients		SDST on graphics tablet
Putzhammer et al⁴¹	Drug-naive schizophrenic patients (25)	/	?	In addition: 14 patients lorazepam and 12 patients biperiden	Movement analysis of gait	Relative to the healthy controls, all patients exhibited decreased gait velocity due to shorter stride length while cadence (steps per minute) was not affected. Conventional antipsychotics intensified the problem, whereas atypicals did not cause additional gait disturbances.
	Schizophrenic patients treated with CNL (16)
	Schizophrenic patients treated with AAP (25)
	Healthy controls (25)
Putzhammer et al⁴⁴	Drug-naive schizophrenic patients (14)	36	Inpatients	In addition: 8 patients in total lorazepam and 5 patients in total biperiden	Movement analysis of gait	Compared with the healthy controls, all patients had decreased gait velocity due to shorter stride length. The most striking difference was observed between the patients on CNL and the controls. Impaired gait parameters can be normalized in schizophrenic patients by external stimulation via treadmill walking.
	Schizophrenics treated with CNL (14)	38
	Schizophrenics treated with olanzapine (14)	35
	Healthy controls (14)	46
Schroder et al¹²⁴	Schizophrenics (12)	28	?	9 clozapine, 2 conventionals+ biperiden, and 1 drug free	Pronation/supination device during fMRI	No differences in measures of motor retardation (repetition rate and amplitude) between patients and controls. Variability was significantly increased in the patients and activation of sensorimotor and SMA cortices was significantly decreased.
Schroder et al¹²⁴	Healthy controls (12)	27	?	9 clozapine, 2 conventionals+ biperiden, and 1 drug free	Pronation/supination device during fMRI
Tigges et al¹²⁵	Schizophrenics (27)	31.0	Inpatients	13 drug free and 14 CPZ-eq: 507 mg	Handwriting on writing tablet	Patients had longer stroke durations and decreased automatization. Stroke length and velocity were less regular in the treated patients. Stroke-length irregularity was higher in patients treated with atypicals and not with typicals. Positive and negative symptoms had little relation to the handwriting measures.
Tigges et al¹²⁵	Healthy controls (31)	33.3	Inpatients	13 drug free and 14 CPZ-eq: 507 mg	Handwriting on writing tablet
Van Hoof et al³⁷	Schizophrenics (20)	39.9	Inpatients	CPZ-eq = 710	SDST on a writing tablet	The depressed patients demonstrated an overall slowing in matching and writing times, whereas the schizophrenic patients only displayed prolonged matching times in comparison with both the depressed patients and the healthy controls.
	Depressed patients (20)	47.0
	Healthy controls (20)	43.1
Yang et al⁸¹	Schizophrenics (28)	29.3	19 outpatients and 9 other (?)	19 neuroleptic treatment and 9 medication free	FTT	The FTT showed the strongest correlation with D2 receptor binding, while the WCST and attention test had no correlation with D2 receptor binding.

Note: AAP = atypical antipsychotics, CNL = conventional neuroleptics, CPZ-eq = chlorpromazine equivalents, FTT = finger-tapping test, SDST = Symbol Digit Substitution test, SMA = supplementary motor area, TMT = Trailmaking Test, WCST = Wisconsin Card Sorting Test, RT = reaction time, PS = psychomotor slowing, and NOS = not otherwise specified.