The Relationship between Cognitive Decline and Psychopathology in Patients with Schizophrenia and Bipolar Disorder

Abstract

ObjectiveThe primary goals of the present study were to assess intellectual function in participants with schizophrenia or bipolar disorder (BD) and to investigate the relationships between cognitive decline and the severity of each type of psychopathology.MethodsThe present study included 51 patients with schizophrenia and 42 with BD who were recruited from the psychiatry outpatient clinic of Jeju University Hospital between March 2011 and March 2014. The Korean Wechsler Adult Intelligence Scale (K-WAIS) was administered to each of the 93 participants, and they were categorized into two groups based on their current intelligence quotient (IQ) and their estimated premorbid IQ: severely impaired group (SIG) and mildly impaired group (MIG). The Minnesota Multiple Personality Inventory (MMPI) and the Brief Psychiatric Rating Scale (BPRS) were used to assess psychopathology.ResultsThe SIG schizophrenia participants exhibited significantly higher scores on the frequent (F) and schizophrenia (Sc) subscales of the MMPI, but significantly lower scores on the correction (K) and psychopathic deviate (Pd) subscales compared with the MIG schizophrenia participants. Furthermore, the BPRS scores were significantly higher in the SIG schizophrenia participants relative to the MIG schizophrenia participants. The SIG BD participants had significantly higher F, masculinity-femininity (Mf), paranoia (Pa), and Sc but significantly lower Pd scores compared with the MIG BD participants.ConclusionThe present findings revealed a significant discrepancy between the estimated premorbid levels of cognitive function and current cognitive function in participants with schizophrenia or BD. Moreover, this discrepancy was correlated with severity of psychopathology in both groups.

Common and distinct structural features of schizophrenia and bipolar disorder: The European Network on Psychosis, Affective disorders and Cognitive Trajectory (ENPACT) study

“…Currently, the dimensional approach for diagnosing mental disorders has revitalized the question of shared characterization of SCZ and BD in a dimensional continuum view, as opposed to a categorical dichotomous vision. This has been supported by the neurobiological research that has shown that SCZ and BD exhibit shared genetic [ 4 , 5 ] and neurocognitive determinants [ 6 ], besides clinical features [ 7 ]. The investigation of the neuroanatomical characteristics of the two disorders can therefore help to further delineate their common and different pathophysiological bases, opening the door to the development of tailored instruments with higher diagnostic specificity.…”

Staging Models in Bipolar Disorder: A Systematic Review of the Literature

“… 37) Accompanying these phenomena are cognitive deterioration and functional decline in such areas as occupation, social relationships, and financial independence with eventual loss of autonomy. 38) Research efforts in the last few decades have started to uncover the neurobiological correlates of the worsening clinical course in BD. The term “neuroprogression” has been increasingly used to define the pathological reorganization of the central nervous system (CNS) which arises as the result of several insults, such as inflammation and oxidative stress.…”

A polygenic risk score analysis of psychosis endophenotypes across brain functional, structural, and cognitive domains

“…The included measures are all putative endophenotypes for psychosis and were compatible across centers, thus reaching substantial sample sizes: P300 event‐related potential: reduced amplitude and prolonged latency of the P300 wave have consistently been found in patients with psychotic illnesses as well as in their unaffected relatives, compared to controls (Bestelmeyer, Phillips, Crombie, Benson, & St.Clair, ; Blackwood, St Clair, Muir, & Duffy, ; Bramon et al, ; Díez et al, ; Mondragón‐Maya et al, ; Pierson, Jouvent, Quintin, Perez‐Diaz, & Leboyer, ; Price et al, ; Schulze et al, ; Turetsky et al, ; Weisbrod, Hill, Niethammer, & Sauer, ; Winterer et al, ). The P300 is thought to be a correlate of attention and working memory (Ford, ; Näätänen, ). Cognitive performance: deficits on cognitive tests such as digit span (measuring working memory), block design (measuring working memory and spatial visualization), and the Rey Auditory Verbal Learning Task (RAVLT) immediate and delayed recall (measuring short and long term verbal memory, respectively) are common and persistent across psychotic disorders (Bora, Yucel, & Pantelis, ; Bora & Pantelis, ; Gur et al, ; Heinrichs & Zakzanis, ; Kim et al, ; Lee et al, ). Abnormalities are often observed before the onset of the illness as well as in unaffected relatives (Birkett et al, ; Forbes, Carrick, McIntosh, & Lawrie, ; Glahn et al, ; Ivleva et al, ; Park & Gooding, ; Reichenberg et al, ; Saperstein et al, ; Snitz, Macdonald, & Carter, ). Lateral ventricular volume: increased ventricular volume is a highly replicated finding in patients with psychosis compared to controls (Boos, Aleman, Cahn, Hulshoff Pol, & Kahn, ; Crespo‐Facorro et al, ; Fannon et al, ; Fusar‐Poli et al, ; Haijma et al, ; Kempton, Stahl, Williams, & DeLisi, ; Kumra et al, ; McDonald et al, , ; Sharma et al, ; Shenton, Dickey, Frumin, & McCarley, ; Strasser et al, ; Wright et al, ).…”