ABSTRACT
OBJECTIVE: Many schizophrenia patients remain undiagnosed and untreated for long periods of time. It has been suggested that untreated psychosis may have deleterious neurotoxic effects. However, studies examining the correlates of untreated initial psychosis duration have been mixed. Previous MRI studies have reported no significant correlations between duration of untreated initial psychosis and brain volumes but have not examined specific brain regions that may be most susceptible to neuronal damage. METHOD: The authors investigated the relationship between duration of untreated initial psychosis and hippocampus morphology in 105 patients with first-episode DSM-IV schizophrenia spectrum disorders. High-resolution MRI-based hippocampal volume measurements were obtained by using a semiautomated artificial neural network method. RESULTS: There were no significant associations between hippocampal volumes and duration of untreated initial psychosis. When the patient group was split around the median duration of untreated initial psychosis (13 weeks), there were again no significant differences in left, right, or total hippocampal volume between groups. CONCLUSIONS: These findings do not support the hypothesis that psychosis is neurotoxic or that delaying antipsychotic drug treatment results in reduced hippocampal volumes.
Subject(s)
Hippocampus/anatomy & histology , Magnetic Resonance Imaging/statistics & numerical data , Schizophrenia/diagnosis , Schizophrenia/drug therapy , Adult , Antipsychotic Agents/administration & dosage , Antipsychotic Agents/therapeutic use , Diagnostic and Statistical Manual of Mental Disorders , Drug Administration Schedule , Female , Functional Laterality/physiology , Humans , Male , Neural Networks, Computer , Psychiatric Status Rating Scales , Time FactorsABSTRACT
BACKGROUND: There is increasing evidence that, aside from motor coordination, the cerebellum also plays an important role in cognition and psychiatric disorders. Our previous studies support the hypothesis that cerebellar dysfunction may disrupt the cortico-cerebellar-thalamic-cortical circuit and, in turn, lead to cognitive dysmetria in schizophrenia. The goal of this study was to investigate cerebellar dysfunction in schizophrenia by examining the clinical, cognitive, and neuroanatomic correlates of cerebellar neurologic signs in schizophrenia patients. METHODS: We compared the prevalence of cerebellar neurologic signs in 155 neuroleptic-naive schizophrenia patients against 155 age- and gender-matched healthy control subjects. Differences in clinical characteristics, standardized neuropsychologic performance, and magnetic resonance imaging brain volumes between patients with and without cerebellar signs were also examined. RESULTS: Patients had significantly higher rates of cerebellar signs than control subjects, with coordination of gait and stance being the most common abnormalities. Patients with lifetime alcohol abuse or dependence were no more likely than those without alcoholism to have cerebellar signs. Presence of cerebellar signs in patients was associated with poorer premorbid adjustment, more severe negative symptoms, poorer cognitive performance, and smaller cerebellar tissue volumes. CONCLUSIONS: These findings lend further support for cerebellar dysfunction in schizophrenia.
