Benzodiazepines, antidepressants do not affect cognition in schizophrenia

Findings presented at the European College of Neuropsychopharmacology Congress suggested that adjunctive benzodiazepine and antidepressant treatment did not affect cognition nor explain cognitive effects of antipsychotics in midlife schizophrenia.

To determine the effects of lifetime and current exposure to benzodiazepines and antidepressants, lifetime and current trends of antipsychotic use, and antipsychotic polypharmacy on cognitive performance in midlife schizophrenia, researchers evaluated 60 participants with schizophrenia from the Northern Finland birth cohort of 1966.

Participants were assessed after 16.5 years of illness at 43 years of age. Assessments included the Abstract Inhibition and Working Memory Task, California Verbal Learning Test, Visual Object Learning Test, verbal fluency, visual series, vocabulary, digit span and matrix reasoning. Medical records and interviews determined cumulative lifetime defined daily dose years and cross-sectional doses.

Researchers did not find significant associations between lifetime cumulative defined daily dose years and current cross-sectional doses of benzodiazepines and antidepressants.

When adjusting for gender, onset age and lifetime hospital treatment days, being antipsychotic-free for at least 1 year at any time since treatment start (P = .028) or at least 11 months before cognitive examination (P = .007) was associated with better global cognitive performance.

The associations remained after adjustment for other potential confounders.

Cognition was not significantly associated with proportion of long-term antipsychotic use or lifetime or current antipsychotic polypharmacy.

“We should note that because of the observational setting of our study and small sample size, definitive conclusions are difficult to draw, even though in our analyses controlling for severity or duration of illness didn't explain the cognitive findings with antipsychotics,” study researcher Anja Hulkko, MD, of the University of Oulu, Finland, said in the release. “Owing to the extensive birth cohort database, we were able to control for many relevant variables. However, during a long illness course, the risk of missing some important confounders increases — for example, more ill persons with more cognitive problems may also be given more medication. It seems likely that both the illness itself and treatment are associated with the course of cognition.”

Commenting on the study, Kamilla Miskowiak, PhD, of Copenhagen University Hospital, Denmark, said the results are highly interesting and show no long-term cognitive side effects of antidepressants, tranquilizers or low-dose antipsychotic medication in schizophrenia.

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“This is reassuring since many patients are worried about taking these medications because of their potential negative effects on cognition,” Miskowiak said. “In contrast, long-term high-dose antipsychotic medication was associated with poorer cognitive outcome. This underscores the importance of close dose monitoring of antipsychotic medication for these patients to improve their cognitive outcome.” – by Amanda Oldt

Reference:

Hulkko A, et al. Lifetime use of psychiatric medications and cognition at 43 years of age in schizophrenia in the Northern Finland birth cohort 1966. Presented at: European College of Neuropsychopharmacology Congress; Sept. 2-5, 2017; Paris.

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