Intrinsic motivation in schizophrenia: relationships to cognitive function, depression, anxiety, and personality.

The goal of the current project was to assess subjective reports of intrinsic motivation and their relationship to cognitive function, mood, and personality in schizophrenia. The authors used the Motivational Trait Questionnaire to examine 3 components of intrinsic motivation (personal mastery, competitive excellence, motivation related to anxiety). They also examined fluid intelligence, context processing, and working memory, as well as self-reports of mood and personal traits related to motivation. Participants were 66 individuals with schizophrenia or schizoaffective disorder and 44 healthy controls. Self-reports of personal mastery and competitive excellence did not differ between controls and individuals with schizophrenia, though patients did report significantly higher motivation related to anxiety. Among controls, but not patients, self-reports of intrinsic motivation were strongly related to cognitive performance. In contrast, both controls and patients showed similar strong relationships between self-reports of intrinsic motivation and related measures of mood and personality. These results are not consistent with the hypothesis that motivational deficits in schizophrenia reflect impairments in intrinsic motivation. However, they do suggest that the normal relationship between self-reports of intrinsic motivation and cognitive function is disrupted in schizophrenia.

Episodic memory in schizophrenia: the influence of strategy use on behavior and brain activation.

Individuals with schizophrenia demonstrate behavioral and neurobiological deficits in episodic memory. However, recent work suggests that episodic memory deficits in schizophrenia may be mitigated through specific encoding strategies. The current study directly compared brain activity and memory performance associated with two different verbal encoding orientations in the same group of schizophrenia participants, in order to more fully characterize the role of strategy in memory processing in this population. Participants included 18 individuals with schizophrenia and 15 healthy comparison participants. Participants encoded words under two conditions during separate fMRI scanning runs. During Incidental encoding, participants were required to make abstract/concrete judgments for each word. During Intentional encoding, participants were instructed to memorize each word for a later memory test. Free recall and a recognition task (utilizing the Remember/Know paradigm) were performed outside of the scanner. Consistent with prior work, schizophrenia participants recognized more words encoded Incidentally than Intentionally, although free recall remained substantially impaired. Schizophrenia participants were also less likely to give Remember judgments for old words and more likely to give Guess judgments for both old and new words. When functional magnetic resonance imaging data were examined, we found that Incidental encoding was associated with substantially fewer between-group differences (Control>Schizophrenia) than Intentional encoding. Furthermore, schizophrenia participants exhibited intact activity during encoding of items that were subsequently retrieved. Our results suggest that use of an Incidental encoding strategy improved recognition memory among individuals with schizophrenia and resulted in a pattern of encoding-related brain activity that was more similar to that seen in control participants. However, we found that Incidental encoding did not improve free recall in schizophrenia participants and abnormal brain activity in some regions was observed, despite improvements in recognition memory.

The sensitivity and psychometric properties of a brief computer-based cognitive screening battery in a depression clinic.

At present, there is poor accuracy in assessing cognitive and vegetative symptoms in depression using clinician or self-rated measures, suggesting the need for development of standardized tasks to assess these functions. The current study assessed the psychometric properties and diagnostic specificity of a brief neuropsychological screening battery designed to assess core signs of depression; psychomotor retardation, attention and executive functioning difficulties, and impaired emotion perception within an outpatient psychiatry setting. Three hundred eighty-four patients with mood disorders and 77 healthy volunteers participated. A large percentage of patients met diagnostic criteria for Major Depressive Disorder alone (49%) or with another comorbid psychiatric disorder (24%). A brief, 25-min battery of computer-based tests was administered to control participants and patients measuring the constructs of inhibitory control, attention, visual perception, and both executive and visual processing speed. The patient groups performed significantly worse than the control group regardless of diagnosis on visual perception and attention accuracy and processing speed factors. Surprisingly, the anxiety disorder group performed better than several other psychiatric disorder groups in inhibitory control accuracy. Developing valid and reliable measures of cognitive signs in mood disorders creates excellent opportunities for tracking cognitive status prior to initiation of treatment, and allows for reliable retest following treatment.