Post stroke depression
Encyclopedia
Post-stroke depression is considered the most frequent and important neuropsychiatric consequence of stroke
. Approximately one-third of stroke survivors experience major depression. Moreover this condition can have an adverse effect on cognitive function, functional recovery and survival.
The Diagnostic and Statistical Manual (DSM) IV categorizes post-stroke depression as “mood disorder due to a general medical condition (i.e. stroke)” with the specifiers of depressive features, major depressive-like episodes, manic
features, or mixed features. Utilizing patient data from acute hospital admission, community surveys, or out patient clinics previous studies have identified two types of depressive disorders associated with cerebral ischemia
: major depression, which occurs in up to 25% of patients; and minor depression, which has been defined for research purposes by DSM-IV criteria as a depressed mood or loss of interest and at least two but fewer than four symptoms of major depression. Minor depression occurs in up to 30% of patients following stroke.
Prevalence clearly varies over time with an apparent peak 3–6 months after stroke and subsequent decline in prevalence at one-year reaches about to 50% of initial rates. Robinson and colleagues characterized the natural course of major depression after stroke with spontaneous remission typically 1 to 2 years after stroke However, it was also noted that in few cases depression becomes chronic and may persist more than 3 years following stroke . On the other hand, minor depression appeared to be more variable, with both short term and long term depression occurring in these patients .
The scientific community is divided into two “camps” supporting opposing views: some propose a primary biological mechanism with stroke affecting neural circuits involved in mood regulation which in turn causes post-stroke depression , while other researchers claim that post stroke depression is caused by social and psychological stressors that emerge as a result of stroke.
While an integrated bio-psycho-social model
including both biological and psychosocial
aspects of post stroke depression seems warranted, a number of studies clearly suggest that biological mechanisms play a major role in the development of post stroke depression.
Despite this evidence, the association of post-stroke depression to specific brain lesions is still vague and needs replication from various independent groups. Furthermore the cause of post stroke depression at a functional level is not clear.
The only biological model was proposed by Robinson and co-workers: They hypothesized that the depletion of monoaminergic amine
s occurring after stroke play a role in post stroke-depression. They point out that norepinephrine
rgic and serotonergic
nuclei send projections to the frontal cortex and arc posteriorly, running through the deep layers of the cortex
, where they arborize and send terminal projections into the superficial cortical layers. These norepinephrinergic and serotoninergic pathways are disrupted in basal ganglia
and frontal lobe
lesion
s – sites that are shown to be associated with post stroke depression.
However, this model is far from being universally accepted and there are serious objections both to their model and findings showing the association between post-stroke depression and lesion sites.
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...
. Approximately one-third of stroke survivors experience major depression. Moreover this condition can have an adverse effect on cognitive function, functional recovery and survival.
The Diagnostic and Statistical Manual (DSM) IV categorizes post-stroke depression as “mood disorder due to a general medical condition (i.e. stroke)” with the specifiers of depressive features, major depressive-like episodes, manic
Manic
Manić is a suburban settlement of Belgrade, the capital of Serbia. It is located in the municipality of Barajevo.Manić developed on the eastern slopes of the Kosmaj mountain...
features, or mixed features. Utilizing patient data from acute hospital admission, community surveys, or out patient clinics previous studies have identified two types of depressive disorders associated with cerebral ischemia
Ischemia
In medicine, ischemia is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue. It may also be spelled ischaemia or ischæmia...
: major depression, which occurs in up to 25% of patients; and minor depression, which has been defined for research purposes by DSM-IV criteria as a depressed mood or loss of interest and at least two but fewer than four symptoms of major depression. Minor depression occurs in up to 30% of patients following stroke.
Prevalence clearly varies over time with an apparent peak 3–6 months after stroke and subsequent decline in prevalence at one-year reaches about to 50% of initial rates. Robinson and colleagues characterized the natural course of major depression after stroke with spontaneous remission typically 1 to 2 years after stroke However, it was also noted that in few cases depression becomes chronic and may persist more than 3 years following stroke . On the other hand, minor depression appeared to be more variable, with both short term and long term depression occurring in these patients .
The scientific community is divided into two “camps” supporting opposing views: some propose a primary biological mechanism with stroke affecting neural circuits involved in mood regulation which in turn causes post-stroke depression , while other researchers claim that post stroke depression is caused by social and psychological stressors that emerge as a result of stroke.
While an integrated bio-psycho-social model
Biopsychosocial model
The biopsychosocial model is a general model or approach that posits that biological, psychological , and social factors, all play a significant role in human functioning in the context of disease or illness...
including both biological and psychosocial
Psychosocial
For a concept to be psychosocial means it relates to one's psychological development in, and interaction with, a social environment. The individual needs not be fully aware of this relationship with his or her environment. It was first commonly used by psychologist Erik Erikson in his stages of...
aspects of post stroke depression seems warranted, a number of studies clearly suggest that biological mechanisms play a major role in the development of post stroke depression.
- stroke patients show a higher rate of depression compared to orthopedic patients with disabilities of comparable severity.
- Several studies proposed an association with specific lesionLesionA lesion is any abnormality in the tissue of an organism , usually caused by disease or trauma. Lesion is derived from the Latin word laesio which means injury.- Types :...
s (left anterior and basal gangliaBasal gangliaThe basal ganglia are a group of nuclei of varied origin in the brains of vertebrates that act as a cohesive functional unit. They are situated at the base of the forebrain and are strongly connected with the cerebral cortex, thalamus and other brain areas...
lesions and lesions close to frontal pole) and occurrence of post stroke depression. - Some studies reported an association between post-stroke mania and right orbital frontal, basotemporal, basal ganglia lesions.
- It has been shown that patients with anosognosiaAnosognosiaAnosognosia /æˌnɒsɒgˈnəʊsɪə/ is a condition in which a person who suffers disability seems unaware of the existence of his or her disability. Unlike denial, which is a defense mechanism, anosognosia is rooted in physiology...
who are unaware of their disability still develop post stroke depression.
Despite this evidence, the association of post-stroke depression to specific brain lesions is still vague and needs replication from various independent groups. Furthermore the cause of post stroke depression at a functional level is not clear.
The only biological model was proposed by Robinson and co-workers: They hypothesized that the depletion of monoaminergic amine
Amine
Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...
s occurring after stroke play a role in post stroke-depression. They point out that norepinephrine
Norepinephrine
Norepinephrine is the US name for noradrenaline , a catecholamine with multiple roles including as a hormone and a neurotransmitter...
rgic and serotonergic
Serotonin
Serotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...
nuclei send projections to the frontal cortex and arc posteriorly, running through the deep layers of the cortex
Cerebral cortex
The cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain. It plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It is constituted of up to six horizontal layers, each of which has a different...
, where they arborize and send terminal projections into the superficial cortical layers. These norepinephrinergic and serotoninergic pathways are disrupted in basal ganglia
Basal ganglia
The basal ganglia are a group of nuclei of varied origin in the brains of vertebrates that act as a cohesive functional unit. They are situated at the base of the forebrain and are strongly connected with the cerebral cortex, thalamus and other brain areas...
and frontal lobe
Frontal lobe
The frontal lobe is an area in the brain of humans and other mammals, located at the front of each cerebral hemisphere and positioned anterior to the parietal lobe and superior and anterior to the temporal lobes...
lesion
Lesion
A lesion is any abnormality in the tissue of an organism , usually caused by disease or trauma. Lesion is derived from the Latin word laesio which means injury.- Types :...
s – sites that are shown to be associated with post stroke depression.
However, this model is far from being universally accepted and there are serious objections both to their model and findings showing the association between post-stroke depression and lesion sites.