Prefrontal subregions and dimensions of insight in first-episode schizophrenia — A pilot study

Abstract 

Deficits in insight are multidimensional, and include symptom unawareness and misattribution. We and others have observed that these deficits may be related to a prefrontal dysfunction. However, few studies have examined the relationship between specific prefrontal sub-regions and the awareness and attributional dimensions of insight in schizophrenia. This study examined the correlation between insight dimensions of awareness and attribution of symptoms and dorsolateral prefrontal cortex (DLPFC) and orbitofrontal cortex (OFC) volume in 14 subjects with first-episode, antipsychotic-naïve (FEAN) schizophrenia. In addition, 21 healthy subjects provided control data for volumetric assessments. Insight was assessed with Scale to Assess Unawareness of Mental Disorders. Morphometric assessments were adjusted for intra-cranial volume and were conducted by trained raters blind to clinical information using BRAINS-2. Average scores on current awareness of symptoms (1=aware; 5=unaware) were negatively correlated with right DLPFC volume and average scores on current attribution of symptoms (1=attribute; 5=misattribute) with right medial OFC volume. Unawareness and misattribution of symptoms in FEAN schizophrenia may have distinct neuroanatomical bases. DLPFC deficits may have resulted in illness unawareness by interfering with self-monitoring, while OFC abnormalities may have mediated symptom misattribution by conferring aberrant salience to perceived symptomatology.

Keywords: Insight, Dimensions, Prefrontal sub-regions, First-episode schizophrenia