Summary: Typical interventions for schizophrenia do not improve long-term outcomes, even when administered early, a new study reports.
Source: Stony Brook University
A Stony Brook University-led study reveals that, despite the common view that early intervention in schizophrenia slows or stops mental decline, those who receive early intervention eventually experience the same declines as those whose treatment started later. The finding, published online in The American Journal of Psychiatry, suggests that studies of schizophrenia should take into account how long study participants have been symptomatic, otherwise treatments may appear more effective than they actually are.
“Our finding is somewhat counterintuitive. There has been a good amount of evidence suggesting that if you get people who are having their first psychotic episode into treatment as soon as possible, you can avert irreversible declines,” said Lead Author Katherine Jonas, PhD, Postdoctoral Fellow in the Department of Psychiatry in the Renaissance School of Medicine at Stony Brook University. “We found that if you compare people who got into treatment early with those who did not, the early treatment group only appears to have better outcomes because they are often younger, and haven’t been sick as long.”
Jonas and colleagues point out that comprehensive pharmacological and psychosocial treatment has shown to be effective in reducing symptoms and improving quality of life in schizophrenia. However, many patients in the US do not get these treatments. Most receive only antipsychotic medications, which help with hallucinations and delusions but not with other symptoms. Therefore, they caution that “while starting ‘treatment as usual’ earlier may not halt the disease process, comprehensive and sustained care has been shown to improve overall mental health for those with schizophrenia.”
The study evaluated duration of untreated psychosis (DUP) – defined as the amount of time that elapses between psychosis onset and treatment initiation. Data came from the Suffolk County Mental Health Project and included 287 individuals with schizophrenia or schizoaffective disorder. More than 2,000 patient observations spanning from childhood to 20 years after first hospital admission are included in the dataset. Overall mental health was evaluated at multiple points and related to DUP.
The association between long DUP and poor outcomes is well known in the treatment of patients with schizophrenia. Yet Jonas and colleagues found that in this study the association can be explained by lead-time bias.
“Lead-time bias is a phenomenon in which early detection – such as early screening for breast cancer or another disease – appears to improve outcomes because it enlarges the observation window of the disease,” she explained.
The authors conclude in their study that the association between DUP and psychosocial function in schizophrenia may be an artifact of early detection, creating the illusion that early detection is associated with improved outcomes. Given this finding, they emphasize that shortening DUP does not necessarily change long-term illness course. DUP may be more of an indicator of illness stage than a predictor of course.
Co-authors include faculty from the Department of Psychiatry at the Renaissance School of Medicine and in the Department of Applied Mathematics and Statistics at Stony Brook University, and from the Feinstein Institute for Medical Research.
Funding: The research was supported in part by the National Institutes of Health (grant numbers MH44801 and MH094398).
About this neuroscience research article
Source: Stony Brook University Media Contacts: Greg Filiano – Stony Brook University Image Source: The image is in the public domain.
Lead-Time Bias Confounds Association Between Duration of Untreated Psychosis and Illness Course in Schizophrenia
Objective: At first hospitalization, a long duration of untreated psychosis (DUP) predicts illness severity and worse treatment outcomes. The mechanism of this association, however, remains unclear. It has been hypothesized that lengthy untreated psychosis is toxic or that it reflects a more severe form of schizophrenia. Alternatively, the association may be an artifact of lead-time bias. These hypotheses are tested in a longitudinal study of schizophrenia with 2,137 observations spanning from childhood to 20 years after first admission.
Methods: Data were from the Suffolk County Mental Health Project. The cohort included 287 individuals with schizophrenia or schizoaffective disorder. DUP was defined as days from first psychotic symptom to first psychiatric hospitalization. Psychosocial function was assessed using the Premorbid Adjustment Scale and the Global Assessment of Functioning Scale. Psychosocial function trajectories were estimated using multilevel spline regression models adjusted for gender, occupational status, race, and antipsychotic medication.
Results: Both long- and short-DUP patients experienced similar declines in psychosocial function, but declines occurred at different times relative to first admission. Long-DUP patients experienced most of these declines prior to first admission, while short-DUP patients experienced declines after first admission. When psychosocial function was analyzed relative to psychosis onset, DUP did not predict illness course.
Conclusions: The association between DUP and psychosocial function may be an artifact of early detection, creating the illusion that early intervention is associated with improved outcomes. In other words, DUP may be better understood as an indicator of illness stage than a predictor of course.