Outcome studies in schizophrenia

Distinct effects of duration of untreated psychosis on brain cortical activities in different treatment phases of schizophrenia: a multi-channel near-infrared spectroscopy study

BACKGROUND

Duration of untreated psychosis (DUP) has been shown to be associated with both poor short-term and long-term outcomes in schizophrenia. Even so, few studies have used functional neuroimaging to investigate DUP in schizophrenia. In the present study, we used near-infrared spectroscopy (NIRS) to investigate the influence of DUP on brain functions during a verbal fluency test (VFT) in patients with schizophrenia.

METHODS

A total of 62 patients with schizophrenia were included. They were categorized into either short treatment (≤6months, n=33) or long treatment (>6months, n=29) groups based on their duration of treatment. Hemodynamic changes over the frontotemporal regions during a VFT were measured using multi-channel NIRS. We examined the associations between DUP and hemodynamic changes in each group to explore if there were different effects of DUP on brain cortical activity at different treatment durations.

RESULTS

In the long treatment group, we found significant associations between a longer DUP and decreased cortical activity approximately at the left inferior frontal gyrus, left middle frontal gyrus, left postcentral gyrus, right precentral gyrus, bilateral superior temporal gyrus, and bilateral middle temporal gyrus, whereas no associations between DUP and brain cortical activity were observed in the short treatment group.

CONCLUSIONS

Our results indicated that longer DUP may be associated with decreased level of cortical activities over the frontotemporal regions in the long-term. Early detection and intervention of psychosis that shortens DUP might help to improve the long-term outcomes in patients with schizophrenia.

Predictors of outcome in first-episode schizophrenia over the first 4 years of illness

BACKGROUND

The outcome of schizophrenia appears to be more favourable than once thought. However, methodological issues, including the reliance on diagnosis at first presentation have limited the validity of outcome studies to date.

METHOD

We conducted a first-episode follow-up study of 97 patients with DSM-IV schizophrenia over the first 4 years of illness. First presentation and follow-up assessments were compared using paired t tests and a forced-entry regression analysis was used to determine prognostic variables.

RESULTS

There were significant improvements in positive and negative symptoms and global assessment of functioning between first presentation and follow-up. At first presentation, fewer negative symptoms (t=-3.40, p<0.01), more years spent in education (t=3.25, p<0.01), and a shorter duration of untreated psychosis (DUP) (t=-2.77, p<0.01) significantly predicted a better outcome at follow-up.

CONCLUSIONS

The outcome of schizophrenia may not be as pessimistic as once thought and most patients did not display a downward deteriorating course of illness. This study supports the relationship between DUP and outcome beyond the early stages of illness.

Early Psychosis Prevention and Intervention Centre long-term follow-up study of first-episode psychosis: methodology and baseline characteristics

AIM

This paper reports the rationale, methodology and baseline characteristics of a large long-term follow-up study of first-episode psychosis from a geographically defined catchment area.

METHOD

A total of 723 first-episode psychosis patients were recruited from a specialized early psychosis service between 1989 and 2001 and prospectively followed up at a median of 7.4 years after initial presentation. Participants' baseline demographic, clinical and functional characteristics are described. Sampling bias at study recruitment was assessed by comparison with a more complete sample of Early Psychosis Prevention and Intervention Centre (EPPIC) cases rated directly from the medical records.

RESULTS

  At baseline, 57% of the sample were diagnosed with schizophrenia or schizophreniform disorder, whereas the full range of psychotic disorders was represented. Statistical analysis confirmed that the sample recruited was representative of total EPPIC-treated incident cases.

CONCLUSIONS

The EPPIC long-term follow-up study is a large and epidemiologically representative first-episode psychosis cohort that has been subsequently prospectively followed up over a long period. Such a sample provides a rare opportunity to study the course and outcome of psychotic disorders.