Methylphenidate and Memory and Attention Adaptation Training for Persistent Cognitive Symptoms after Traumatic Brain Injury: A Randomized, Placebo-Controlled Trial.

The purpose of this multicenter, prospective, randomized, placebo-controlled study was to evaluate and compare the efficacy of two cognitive rehabilitation interventions (Memory and Attention Adaptation Training (MAAT) and Attention Builders Training (ABT)), with and without pharmacological enhancement (ie, with methylphenidate (MPH) or placebo), for treating persistent cognitive problems after traumatic brain injury (TBI). Adults with a history of TBI at least 4 months before study enrollment with either objective cognitive deficits or subjective cognitive complaints were randomized to receive MPH or placebo and MAAT or ABT, yielding four treatment combinations: MAAT/MPH (N=17), ABT/MPH (N=19), MAAT/placebo (N=17), and ABT/placebo (N=18). Assessments were conducted pre-treatment (baseline) and after 6 weeks of treatment (post treatment). Outcome measures included scores on neuropsychological measures and subjective rating scales. Statistical analyses used linear regression models to predict post-treatment scores for each outcome variable by treatment type, adjusting for relevant covariates. Statistically significant (P<0.05) treatment-related improvements in cognitive functioning were found for word-list learning (MAAT/placebo>ABT/placebo), nonverbal learning (MAAT/MPH>MAAT/placebo and MAAT/MPH>ABT/MPH), and auditory working memory and divided attention (MAAT/MPH>ABT/MPH). These results suggest that combined treatment with metacognitive rehabilitation (MAAT) and pharmacotherapy (MPH) can improve aspects of attention, episodic and working memory, and executive functioning after TBI.

Performance on the Cognitive Estimation Test in schizophrenia.

The Cognitive Estimation Test (CET) is generally considered to be a measure of executive function, but there is little information with respect to its clinical utility in patients with schizophrenia. In the present investigation, we evaluated the clinical utility of the CET in 42 patients with schizophrenia relative to 42 healthy comparison subjects matched for age, gender, and parental education. Construct validity of the CET was examined though correlation with other tests of executive and nonexecutive cognitive functions. Patients with schizophrenia performed more poorly on the CET compared with the healthy comparison group, which could not be accounted for by greater level of depression in the patient sample. In the schizophrenia group, CET was correlated with measures of executive function but also general intellectual functioning, verbal learning, and auditory attention. CET performance was not associated with depression or overall severity of psychopathology in the patient sample. These findings provide support for the clinical utility of the CET in schizophrenia but indicate that both executive and nonexecutive cognitive functions contribute to performance on the measure. Thus, the integrity of other cognitive processes should be taken into consideration when interpreting the presence of a deficit in cognitive estimation in patients with schizophrenia.

Inferential-reasoning impairment in schizophrenia-spectrum disorders.

The performance of 15 participants with schizophrenia-spectrum disorders (SCZ) on an inferential-reasoning task was compared with that of 15 healthy-control participants (HC). The SCZ group showed poorer inferential reasoning than HCs, independent of their negative or positive symptoms. These findings are consistent with previous research showing deficits of reasoning in schizophrenia, and indicate that this deficit is independent of severity of delusions.

Nonclinical obsessive-compulsive symptoms and executive functions in schizophrenia.

The impact of nonclinical obsessive-compulsive symptoms (OCS) on neuropsychological functioning in schizophrenia has received little investigation. The authors evaluated whether severity and subtype of OCS are associated with executive functioning in schizophrenia. Twenty-nine patients with schizophrenia and 32 healthy comparison subjects completed questionnaire and performance-based measures of executive functioning. Overall OCS severity in patients was associated with poorer monitoring and cognitive flexibility. Obsessing, hoarding, and checking were related to poorer executive functioning in daily life. Performance-based scores showed few correlations with OCS. Findings indicate that severity of nonclinical OCS subtypes contributes to the heterogeneity of executive functions in schizophrenia.

Lack of relationship between psychological denial and unawareness of illness in schizophrenia-spectrum disorders.

Numerous theories have been proposed to explain the unawareness of illness that is commonly seen in schizophrenia-spectrum disorders, including the theory that unawareness is the result of a psychological denial mechanism used to mitigate the emotional consequences of having a psychiatric illness. The present study was an attempt to determine whether increased denial (in the form of self-deception) is associated with impaired awareness, consistent with the denial theory. Participants included 40 patients with schizophrenia-spectrum disorders and 25 healthy comparison participants. Patients' levels of awareness and symptom attribution were assessed through interview, and all participants completed self-report questionnaires measuring mood symptoms as well as their use of self-deception. Awareness of negative symptoms was associated with increased depression. However, self-deception was not significantly correlated with awareness measures. When patients were divided on the basis of their awareness and attribution scores, no group differences emerged regarding use of self-deception. The patient group and the healthy comparison group did not differ in their use of self-deception. The current results do not support the psychological denial theory of unawareness of illness in schizophrenia-spectrum disorders.