Abstract
Negative symptoms generally refer to a reduction in normal functioning. In schizophrenia they encompass apathy, anhedonia, flat affect, avolition, social withdrawal and, on some accounts, psychomotor retardation.
Negative symptoms have been identified in other psychiatric disorders, including melancholic depression, and also in neurological disorders, such Parkinson’s disease. Achieving a better understanding of negative symptoms constitutes a priority in mental health. Primarily, negative symptoms represent an unrelenting, intractable and disabling feature for patients, often amounting to a severe burden on families, carers and the patients themselves. Identifying and understanding subgroups within disorders may also contribute to the clinical care and scientific understanding of the pathophysiology of these disorders. The purpose of this paper is to review the current literature on negative symptoms in schizophrenia and explore the idea that negative symptoms may play an important role not only in other psychiatric disorders such as melancholic depression, but also in neurological disorders, such as Parkinson’s disease. In each disorder negative symptoms manifest with similar motor and cognitive impairments and are associated with comparable neuropathological and biochemical findings, possibly reflecting analogous impairments in the functioning of frontostriatal-limbic circuits.
Negative symptoms are a cluster of symptoms generally characterised by the absence of normal levels of activation, initiative, and affect. They are a well established aspect of the symptomatology in schizophrenia. Unlike the episodic, treatment–responsive nature of positive symptoms, negative symptoms in schizophrenia tend to be enduring and less reactive to medication. They are perhaps the most unrelenting and disabling features , constituting a severe burden on relatives as well as on the patient themselves. Over the past decade there has been a resurgence of interest in negative symptoms, related partially to their significant prognostic value and additionally to the development and partial success of atypical antipsychotic medication in treating negative symptoms.
Although negative symptoms are considered an important feature of schizophrenia, they are not pathognomic of it.
Over recent years, the concept of negative symptoms has also been described as a prominent feature, distinct from depression, in other neurological and psychiatric disorders including melancholic depression ; Parkinson’s disease; Alzheimer’s disease; fronto-temporal dementia.
Recognising that negative symptoms are not limited to patients with schizophrenia is important, not only for clinical implications regarding potential treatment, but also to enhance the current understanding of the neurobiological substrate of an apparently homogeneous group of symptoms. To avoid variability within studies and consequent inconsistency between findings, it is essential for both research and clinical purposes to have an understanding of the existence of subgroups. The purpose of this paper is to review the current literature on negative symptoms in schizophrenia and explore the idea that negative symptoms play an important role in other neurological and psychiatric disorders, in particular melancholic depression and Parkinson’s disease. Clinical presentations and aetiological models will be considered. Read the rest of this entry »
Tags:
apathy,
behavioural,
brain,
Brown,
cortex,
depression,
DISEASE,
memory,
Neurocognitive,
nigra,
pathology,
phenomenology,
Pluck,
SAS,
schizophrenia,
striatal,
substantia,
symptom
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02 22nd, 2008| 