Similar neuropsychologic dysfunction across psychosis patient groups
MedWire News: Neuropsychologic dysfunction occurs early in both depression and bipolar disorder with psychosis and is similar to, if less severe than, that seen in first-episode schizophrenia, US researchers have discovered.
Although cognitive dysfunction in psychotic affective disorders has been reported in chronic patients during acute episodes, it is not clear whether neuropsychologic impairments are present at illness onset, vary with symptomatology, and respond differently to pharmacologic treatment.
S Kristian Hill and colleagues from the University of Illinois at Chicago therefore studied 73 first-episode psychotic patients, of who 30 had schizophrenia, 22 bipolar disorder with psychosis, and 21 psychotic depression, as well as 41 healthy controls. In all, 52.1% of patients were naïve to antipsychotics at enrolment.
The team administered the Positive and Negative Syndrome Scale (PANSS), Hamilton Depression Rating Scale, Simpson–Angus Scale for Extrapyramidal Symptoms, and Global Assessment of Function, along with a neuropsychologic battery.
Following 6 weeks of treatment, patients showed clinically and statistically significant reductions in PANSS positive, negative, and overall psychiatric symptoms, as well as depressive symptoms, the team notes in the journal Schizophrenia Research.
All patients were impaired relative to healthy controls on neuropsychologic studies, with schizophrenia patients showing more severe impairment than psychotic bipolar disorder patients on the generalized neuropsychologic composite score.
Interestingly, there were no significant differences in the profiles of neuropsychologic deficits across participant groups. On Hochberg multiple comparisons, there were less severe deficits for verbal memory and reasoning and flexibility in psychotic bipolar disorder patients compared with schizophrenia patients .
While all patients reported fewer depressive symptoms at follow-up, patients with psychotic depression showed the greatest reductions. Schizophrenia patients had significant reductions in negative symptoms at follow-up, but there was no significant change in negative symptom ratings for affective disorder groups over time.
Analysing performance on neuropsychologic tests over time, the researchers found that the combination of practice effects, drug treatment, and clinical stabilization in the patient groups was no greater than practice effects alone in healthy controls.
“Thus, although further empirical support is needed, the present findings suggest that all three of the major psychotic disorders of early adult life are associated with diffuse and persistent neurocognitive dysfunction,” the team concludes.
“Considering the impact of psychosis on cognition and functional status in general, these findings may have important clinical implications for prognosis and treatment development for psychotic affective disorders.”
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By Liam Davenport