Laterality patterns in relation to schizophrenia patients' age at onset

Area of Science:

• Neuroscience
• Psychiatry
• Human Lateralization

Background:

• Abnormal lateralization is frequently observed in schizophrenia.
• Handedness and lateral preferences may influence schizophrenia's age at onset.

Purpose of the Study:

• To investigate the association between handedness, lateral preferences (Luria's signs), and age at onset in schizophrenia patients.
• To determine if specific lateral preferences predict early or late onset of schizophrenia.

Main Methods:

• Two samples of schizophrenia patients (N=76 and N=84) were analyzed.
• Multiple regression analysis was used to assess the relationship between age at onset, handedness, Luria's signs (arm folding, hand clasping, familial sinistrality, eye dominance), and gender.
• Replication set confirmed findings from the initial sample.

Main Results:

• Right-handers with right arm folding and left-handers with left arm folding showed an early age at onset.
• Opposite preferences were associated with a late age at onset.
• Ambilaterality signs, such as left eye dominance in right-handers and familial sinistrality in left-handers, predicted early onset.

Conclusions:

• Specific lateral preferences are significant predictors of age at onset in schizophrenia.
• Lateral preferences should be considered alongside other factors when assessing psychosis risk.
• Findings were robust, confirmed in a replication set.