Antecedents, including motor functioning, are usually subtle deviations in development that may become evident during childhood or adolescence. The presence of these deviations may foreshadow the later development of bipolar disorder, however most children who exhibit deviations do not develop the disorder. Studies exploring antecedents are ideally based on representative, population-based samples that follow the group from birth through childhood and adolescence to adulthood.

What is the evidence on motor dysfunction as an antecedent of bipolar disorder?

Moderate to low quality evidence suggests a large effect of poor motor development in the childhood (at ~ 3 years of age) of people who developed mania in adulthood. There may also be more tics and unsteadiness, and more neurological problems in general in the childhood of people who developed affective psychosis in adulthood. Affective psychosis is a broad category that includes bipolar disorder.

October 2021

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Psychomotor ability refers to a wide range of actions involving physical movement related to conscious cognitive processing. Psychomotor ability may be measured by accuracy or speed (reaction time). Examples of psychomotor tests include the Grooved Pegboard test, and the Purdue Pegboard test that measure visual-motor coordination. The Finger Tapping test requires study participants to place their dominant hand face-down and tap as quickly as possible. The task is repeated with the non-dominant hand and assesses motor speed, manual dexterity and lateralisation. The Digit Symbol Substitution test involves paired numbers and symbols. Participants are shown several numbers and asked to write the missing corresponding symbols as quickly as possible, measuring motor ability and attention. The Pursuit Rotor Motor task presents participants with a turntable with a dot in the centre that they must hold with a flexible metal wand as the turntable spins, measuring motor coordination and learning. The Star Mirror Tracing task asks participants to trace a star while only looking at their hand in the reflection of a mirror, assessing visual-motor learning.

What is the evidence for impaired psychomotor ability?

Compared to people without schizophrenia, moderate to high quality evidence suggests poor psychomotor ability in people with schizophrenia, including people with first-episode schizophrenia, or early onset schizophrenia (< 16 years old). People at clinical high-risk for psychosis also showed poorer psychomotor ability compared to controls.

Compared to people with affective psychoses such as bipolar disorder, moderate to high quality evidence found a small effect of poor psychomotor and mental speed in people with schizophrenia.

In general, high quality evidence found greater improvement in motor skills in people taking second generation antipsychotics compared to people taking first generation antipsychotics. Specifically, moderate quality evidence suggests people taking clozapine may show improvements in motor skills after treatment, while people taking olanzapine, quetiapine, risperidone or haloperidol show no improvements.

High quality evidence found a small effect of better psychomotor skills in people with a psychotic disorder and a substance use disorder when compared to people with a psychotic disorder without a substance use disorder. Moderate quality evidence found a large effect of poor motor performance in people with schizophrenia and antisocial traits compared to people with antisocial traits without schizophrenia.

March 2022

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Antecedents such as motor dysfunction are subtle deviations in development that may become evident during childhood or adolescence. The presence of these deviations may foreshadow the later development of schizophrenia, however most children who exhibit these antecedents do not develop the disorder. Studies exploring antecedents are ideally based on representative, population-based samples that follow the group from birth through childhood and adolescence to adulthood. These studies can provide unique insights into the changes in developmental trajectories that may be associated with schizophrenia.

What is the evidence for motor dysfunction as an antecedent of schizophrenia?

High quality evidence finds schizophrenia in adulthood is associated with a medium-sized effect of delay in walking unsupported in infancy, and small effects of delays in standing and sitting unsupported in infancy.

High quality evidence suggests youth ≤ 16 years who developed schizophrenia in adulthood were more likely to display deficits in motor function than youth who did not develop the disorder (medium-sized effect).

March 2022

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