Cognitive deficits in recent-onset and chronic schizophrenia

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Psychology

Background:

• Cognitive dysfunction is a core feature of schizophrenia, impacting daily functioning.
• Evidence suggests cognitive impairments precede the onset of schizophrenia.
• The progression of cognitive deficits from schizophrenia onset to chronic stages remains less understood.

Purpose of the Study:

• To investigate the trajectory of cognitive deficits in schizophrenia across different illness durations.
• To differentiate between age-related cognitive changes and schizophrenia-specific deficits.
• To assess a broad range of cognitive functions in recent-onset versus chronic schizophrenia patients.

Main Methods:

• Cross-sectional study design involving 41 recent-onset schizophrenia patients and 106 chronic schizophrenia patients.
• Inclusion of matched control groups (43 for recent-onset, 105 for chronic) to account for cohort and diagnosis effects.
• Assessment of diverse cognitive functions, including problem-solving, fine motor dexterity, and episodic memory recall.

Main Results:

• All cognitive measures demonstrated significant effects of diagnosis (schizophrenia).
• Select measures of problem-solving and fine motor dexterity showed diagnosis-by-cohort interactions, suggesting deficits may progress beyond normal aging.
• Poorer episodic memory recall correlated with longer illness duration, though most deficits were comparable between recent-onset and chronic schizophrenia.

Conclusions:

• Cognitive deficits are a pervasive feature of schizophrenia, evident early and persisting throughout the illness course.
• While most cognitive impairments are stable from recent-onset to chronic schizophrenia, some deficits may worsen with age.
• Findings highlight the need for interventions targeting cognitive dysfunction across all stages of schizophrenia.