Nils Inge Landrø

Memory functioning in patients with primary fibromyalgia and major depression and healthy controls

Memory functioning was assessed in 25 primary fibromyalgia (FM) patients by comparing them with 22 major depressed patients and 18 healthy controls. A broad range of short- and long-term memory tasks were included. Both major depressed and FM patients were significantly impaired on long-term memory tasks requiring effortful processing, compared to healthy controls. When the depressive status of the fibromyalgia patients was accounted for, only the subsample with a lifetime major depressive disorder showed memory impairment as compared with the healthy controls.

Impairment across executive functions in recurrent major depression.

Depression is associated with impairment of cognitive functions, and especially executive functions (EFs). Despite the fact that most depressed patients experience recurrence of episodes, the pattern and the severity of executive impairment have not been well characterized in this group of depressed patients. We asked if and to what extent these patients were impaired on a range of neuropsychological tests measuring EFs, and also when confounding factors were adjusted for. Forty-five patients (aged 19–51 years) with moderate to severe (Hamilton score >18) recurrent major depressive disorder (DSM-IV) were compared to 50 healthy controls matched on age, education, gender and intellectual abilities. The subjects were administered a set of neuropsychological tests that assesses sub-components of EFs. The depressed patients were impaired compared to the control group on all selected tests, with a severity of impairment within −1 standard deviation from the control group mean. The group difference was statistically significant for eight of the 10 EFs that were assessed. These were measures of verbal fluency, inhibition, working memory, set-maintenance and set-shifting. The group difference was still significant for all sub-components except for set-shifting (Wisconsin Card Sorting Test) and planning (Tower of London), when additional medication and retarded psychomotor speed was adjusted for. In conclusion, the depressed subjects were mildly impaired across a wide range of EFs. This may have a negative impact on everyday functioning for this group of patients.

Attention profile in schizophrenia compared with depression: differential effects of processing speed, selective attention and vigilance

Objective: The aim of the study is to investigate whether subjects with schizophrenia and major depression display attention deficits for different reasons.

Interactive Effects of Sex and 5-HTTLPR on Mood and Impulsivity During Tryptophan Depletion in Healthy People

BACKGROUND Serotonin (5-HT) plays a central role in mood regulation and impulsivity. We studied whether healthy men and women react differently on mood and impulsivity measures during acute tryptophan depletion (ATD). We also studied the relative contribution of a functional length triallelic polymorphism in the promoter region of the serotonin transporter, designated 5-HTTLPR, to the behavioral responses to ATD. METHODS Thirty-nine men and 44 women participated in a randomized, double-blind, parallel group ATD study. Behavioral measures of impulsivity and mood were obtained. RESULTS During ATD, women reported mood reduction and showed a cautious response style, which is commonly associated with depression. Men showed an impulsive response style and did not report mood reduction. The 5-HTTLPR influenced the mood response to ATD in women. CONCLUSIONS Healthy men became more impulsive, whereas healthy women showed mood reduction in response to ATD. This suggests that 5-HT could be one mechanism contributing to the sex differences in the prevalence of mood and impulsivity disorders. The influence of 5-HTTLPR on mood responses in women further substantiates the relevance of this variant in the pathophysiology of at least a subgroup of patients with major depressive disorder.

Neuropsychological test profiles in schizophrenia and non-psychotic depression.

Objective:  The study examined to what degree schizophrenia is characterized by a neuropsychological (NP) test profile specific in shape and level compared with depression and normal functioning.

Cortisol level predicts executive and memory function in depression, symptom level predicts psychomotor speed

Objective:  On a group level depression is related to hypercortisolism and to psychomotor retardation, executive dysfunction and memory impairment. However, intra‐group heterogeneity is substantial. Why some are impaired while others remain in the normal range, is not clear. The present study aims at discerning the relative contribution of present symptom severity and hypercortisolism to impairment in the three domains of cognition.

Sensitivity and specificity of memory dysfunction in schizophrenia: A comparison with major depression

Fifty-three schizophrenic subjects were compared to 50 patients with major depression and 50 normal controls on measures of working memory, declarative memory and malingering. The schizophrenic group scored 1–2 SDs below controls on all measures, while depressive patients exposed only lesser deficits in working memory and free recall. The memory deficit of the schizophrenic subjects was disproportionately greater than their intellectual decline. Differences between clinical groups could not be explained by differences in IQ, clinical symptom load or demographic characteristics. This indicates that impaired memory is a particular sensitive symptom of schizophrenia and that the impairment is specific to the illness. Working memory failure was prominent in both clinical groups. The schizophrenic subjects displayed primarily an acquisition failure, while the depressed group showed retrieval difficulties.

Attentional and executive dysfunctions in schizophrenia and depression: evidence from dichotic listening performance

BACKGROUND We compared performance on a dichotic listening (DL) task between schizophrenic, depressed, and healthy control subjects. A variant of the traditional DL paradigm was used in which the subjects were required to focus attention either on the left (forced-left condition) or right (forced-right condition) ear stimulus. METHODS The subjects were 51 patients with a DSM-IV diagnosis of schizophrenia, 49 patients with recurrent unipolar major depression, and 49 healthy control subjects. They were tested with a consonant-vowel syllables dichotic listening task under three attentional instructions. RESULTS There was a significant overall right ear advantage during the nonforced condition, which increased dramatically during the forced-right condition and was eliminated during the forced-left condition. The depressed patients showed no signs of impairments compared with the healthy control group. Thus, they showed a right ear advantage during the nonforced and forced-right conditions, which was shifted to a left ear advantage during the forced left condition. The schizophrenic patients, however, were impaired on the forced-left condition compared with the healthy control and depressed subjects. CONCLUSIONS The results are discussed in terms of separating attentional and inhibitory executive impairments in schizophrenia and depression, taking into consideration illness duration and information-processing demands.

Depressive symptoms account for deficient information processing speed but not for impaired working memory in early phase multiple sclerosis (MS)

Depressive symptoms may influence neuropsychological functioning negatively. A substantial proportion of multiple sclerosis (MS) patients exhibit neuropsychological impairments and depressive symptomatology is more common in MS as compared to healthy controls and to other neurological diseases. The objectives of the present study were to assess information processing speed, working memory and executive functions in early phase MS and to investigate whether severity of depressive symptoms account for these aspects of cognition in MS. The patients show slowed information processing speed and impaired working memory, whereas executive functioning, as measured with the Wisconsin Card Sorting Test, is unaffected. Depressive symptoms account for slowed information processing speed, but not for impaired working memory.

Cognitive functioning in adolescents with schizophrenia spectrum disorders

In contrast to studies of cognitive functioning in adults with schizophrenia, there has been a relative paucity of studies assessing adolescents with schizophrenia. We investigated cognitive functioning in 22 adolescents with schizophrenia spectrum disorders compared with 30 healthy adolescents. The patient group demonstrated impaired performance on all of the functions investigated except sustained attention. Against the background of this broad impairment, executive function and psychomotor speed were the most impaired, sustained attention was spared, while preattentional processing, early visual information processing, visual long-term memory, auditory short-term memory and working memory emerged as relative deficits. The study shows that adolescents with schizophrenia spectrum disorders demonstrate a similar pattern of cognitive functioning to adults in all areas, except sustained attention.