Descriptive Psychopathology: The Signs and Symptoms of ...

76 Section 1: Present, past, and futurespatial orientation. 120 Manic-depressive patients with an early onset illness, whoare psychotic, who are chronically ill and are elderly tend to have more diffuseand greater cognitive impairment. 121Neuroimaging studies correlate well with the cognitive deficits. Hypometabolismin the dorsolateral prefrontal circuitry is reported. Prefrontal and subgenucingulate volumes are reduced. Findings of hippocampal and amygdala volumesare inconsistent, some studies showing reduction 122 while others report enlargementof these structures. 123 Most neuroimaging studies report some alteration intemporal–limbic and frontal structures.Cognitive deficits observed in patients with depressive illness are associatedwith the neurotoxic effects of the abnormal stress response state affecting hippocampal/amygdalaand frontal–subcortical systems. 124 Acutely, poor workingmemory and an inability to sustain concentration are reported. Cognition canbe preservative, and sufferers have difficulty making decisions. When comparedto other depressed patients, melancholic patients have impaired response selection,set shifting, and spontaneous recall. 125 The deficits correlate with severity ofillness. More severely ill depressed patients exhibit more frontal and executivedeficits, and a reversible dementia (pseudodementia) is seen in severely ill oldermelancholic patients. Verbal and visual memory and episodic memory impairmentis associated with hippocampal volume loss that may become permanent.The cognitive difficulties of melancholic patients usually remit with successfulantidepressant drug treatment or electroconvulsive therapy. Many, however,continue to show deficits after remission. 126 Elevated cortisol levels, seen in manymelancholic patients and most patients who are psychotically depressed, areassociated with poorer cognitive performance especially related to verbal memoryfor lists of words and working memory. 127 Cortisol levels correlate with executivedysfunction and with difficulty in processing stimuli into storable information,leading to memory problems. 128Neuroimaging findings correlate with the cognitive problems. 129 Depressedpatients have perfusion defects in temporal lobe and frontal lobes. 130 They alsoshow hippocampal and caudate nucleus volume loss. 131 Frontal atrophy is alsoreported in patients with psychotic depression and first depressions occurring inlate life. 132The neurology of hallucinations and delusionsPerceptual disturbancesHallucinations and perceptual distortions are associated with lesions or dysfunctionanywhere along sensory modality-specific pathways. Perceptual disturbancesassociated with neuropsychiatric disease, however, are most commonly related to