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Psychosis is a generic psychiatric term for mental states in which
the components of rational thought and perception are severely impaired.
Persons experiencing a psychosis may experience hallucinations,
hold paranoid or delusional beliefs, demonstrate personality changes
and exhibit disorganized thinking (see thought disorder). This is
usually accompanied by features such as a lack of insight into the
unusual or bizarre nature of their behavior, difficulties with social
interaction and impairments in carrying out the activities of daily
living. Essentially, a psychotic episode involves loss of contact
with reality, sometimes termed "loss of reality testing."
Overview
Psychosis is usually considered by mainstream psychiatry to be
a symptom of severe mental illness. Although it is not exclusively
linked to any particular psychological or physical state, it is
particularly associated with schizophrenia, bipolar disorder (manic
depression) and severe clinical depression. There are also several
physical circumstances that can induce a psychotic state, including
electrolyte disorder, urinary tract infections in the elderly, pain
syndromes, drug toxicity, and drug withdrawal (especially alcohol,
barbiturates, and sometimes benzodiazepines), as well as infections
of or injuries to the brain (these psychoses are now more commonly
referred to as organic mental disorders).
It is not uncommon in cases of brain injury and may occur after
drug use, particularly after drug overdose, chronic use, and during
drug withdrawal. Certain compounds may be more likely to induce
psychosis, and some individuals may show greater sensitivity than
others. Drugs can induce true psychosis two ways, due to drug intoxication,
or due to drug withdrawal. Anticholinergic drugs (atropine, scopolamine,
cortisone Jimson weed, most antihistamines (diphenhydramine, dimenhydrinate,
hydroxizine, etc)) can induce a true psychotic state which will
abate once the acute effects of the drug wear off. So, of course,
can certain "street" drugs such as PCP, cocaine, amphetamines
and hallucinogens.
Drugs that have general depressant effects on the central nervous
system, especially alcohol and barbiturates, do not induce psychosis
during use, and actually can decrease psychotic symptoms, but withdrawal
from them induces a state of hyperactivity that is indistinguishable
from psychosis. The withdrawal from barbiturates and alcohol can
be particularly dangerous as not only is there a severe impairment
of reality testing with acting out on psychotic delusions, there
is a possibly mortal effect upon the body.
Chronic psychological stress is also known to cause psychotic states;
however, the exact mechanism is uncertain. Short-lived pychosis
triggered by stress is known as brief reactive psychosis.
The term psychosis should be distinguished from the concept of
insanity, which is a legal term denoting that a person should not
be criminally responsible for his actions. Similarly, it should
be distinguished from psychopathy, a personality disorder often
associated with violence, lack of empathy and socially manipulative
behaviour. Despite the fact that both are colloquially abbreviated
to 'psycho', psychosis bears little similarity to psychopathy's
core features, particularly with regard to violence, which rarely
occurs in psychosis, and the distortion of perceived reality, which
rarely occurs in psychopathy.
It should also be distinguished from the state of delirium, in
that a psychotic individual may be able to perform actions that
require a high level of intellectual effort in clear consciousness.
Finally, it should be distinguished from mental illness. Psychosis
may be regarded as a symptom of other mental illnesses, but as a
descriptive concept it is not considered an illness in its own right.
For example, persons with schizophrenia can have long periods without
psychosis, and persons with bipolar disorder and depression can
have mood symptoms without psychosis. Conversely, psychosis can
occur in persons without chronic mental illness as a result of an
adverse drug reaction or extreme stress.
During the 1960s and 1970s, psychosis was of particular interest
to counterculture critics of mainstream psychiatric practice who
argued that it may simply be another way of constructing reality
and is not necessarily a sign of illness. For example, R. D. Laing
argued that psychosis is a symbolic way of expressing concerns in
situations where such views may be unwelcome or uncomfortable to
the recipients. Thomas Szasz focused on the social implications
of labelling people as psychotic; a label which he argues unjustly
medicalises different views of reality so such unorthodox people
can be controlled by society. Scientology has repudiated the concept
completely.
Generally, however, advances in both differential diagnosis and
studies of the biochemistry of psychotic and non-psychotic individuals
has established that there are usually underlying, physical causes
(not always yet well understood) for the appearance of a psychosis,
and that psychotropic intervention can effectively minimize or eliminate
the symptomatology within a relatively rapid amount of time, restoring
without altering the patient's usual interests, ambitions, dreams,
skills, talents and ability to safely conduct his/her daily life.
In the United States and Europe, few reputable practitioners, since
the 1990s, have approached psychosis outside this scientific frame
of reference.
Etymology - The word psychosis was first used by Ernst von Feuchtersleben
in 1845 as an alternative to insanity and mania and stems from the
Greek psykhe (mind) and osis (diseased or abnormal condition). The
word was used to distinguish disorders which were thought to be
disorders of the mind, as opposed to neurosis, which was thought
to stem from a disorder of the nerves.
Psychotic experience
A psychotic episode can be significantly coloured by mood. For
example, people experiencing a psychotic episode in the context
of depression may experience persecutory or self-blaming delusions
or hallucinations, whilst people experiencing a psychotic episode
in the context of mania may form grandiose delusions or have an
experience of deep religious significance.
Although usually distressing and regarded as an illness process,
some people who experience psychosis find beneficial aspects and
value the experience or revelations that stem from it.
Hallucinations
Hallucinations are defined as sensory perception in the absence
of external stimuli. Psychotic hallucinations may occur in any of
the five senses and take on almost any form, which may include simple
sensations (such as lights, colours, tastes, smells) to more meaningful
experiences such as seeing and interacting with fully formed animals
and people, hearing voices and complex tactile sensations.
Auditory hallucinations, particularly the experience of hearing
voices, are a common and often prominent feature of psychosis. Hallucinated
voices may talk about, or to the person, and may involve several
speakers with distinct personas. Auditory hallucinations tend to
be particularly distressing when they are derogatory, commanding
or preoccupying. However, the experience of hearing voices need
not always be a negative one, as outlined by the Hearing Voices
Movement informed by the research of Prof. Marius Romme.
Delusions and paranoia
Psychosis may involve delusional or paranoid beliefs. Karl Jaspers
classified psychotic delusions into primary and secondary types.
Primary delusions are defined as arising out-of-the-blue and not
being comprehensible in terms of normal mental processes, whereas
secondary delusions may be understood as being influenced by the
person's background or current situation.
Thought disorder
Thought disorder describes an underlying disturbance to conscious
thought and is classified largely by its effects on speech and writing.
Affected persons may show pressure of speech (speaking incessantly
and quickly), derailment or flight of ideas (switching topic mid-sentence
or inappropriately), thought blocking, rhyming or punning.
Lack of insight
One important and puzzling feature of psychosis is usually an accompanying
lack of insight into the unusual, strange or bizarre nature of the
person's experience or behaviour. Even in the case of an acute psychosis,
sufferers may seem completely unaware that their vivid hallucinations
and impossible delusions are in any way unrealistic. This is not
an absolute; however, insight can vary between individuals and throughout
the duration of the psychotic episode.
In some cases, particularly with auditory and visual hallucinations,
the patient has good insight and this makes the psychotic experience
even more terrifying in that the patient realizes that he should
not be hearing voices, but does.
Medical understanding of psychosis
There are a number of possible causes for psychosis. Psychosis
may be the result of an underlying mental illness such as Bipolar
disorder (also known as manic depression), and schizophrenia. Psychosis
may also be triggered or exacerbated by severe mental stress and
high doses or chronic use of drugs such as amphetamines, LSD, PCP,
cocaine or scopolamine. However, incidence of psychosis resulting
from a single administration of any drug is rare, although cases
have been reported in the medical literature suggesting a person's
sensitivities to new compounds can be unpredictable. Sudden withdrawal
from CNS depressant drugs, such as alcohol and benzodiazepines,
may also trigger psychotic episodes. As can be seen from the wide
variety of illnesses and conditions in which psychosis has been
reported to arise (including for example, AIDS, leprosy, malaria
and even mumps) there is no singular cause of a psychotic episode.
The division of the major psychoses into manic depressive insanity
(now called bipolar disorder) and dementia praecox (now called schizophrenia)
was made by Emil Kraepelin, who attempted to create a synthesis
of the various mental disorders identified by 19th-century psychiatrists,
by grouping diseases together based on classification of common
symptoms. Kraepelin used the term 'manic depressive insanity' to
describe the whole spectrum of mood disorders, in a far wider sense
than it is usually used today. In Kraepelin's classification this
would include 'unipolar' clinical depression, as well as bipolar
disorder and other mood disorders such as cyclothymia. These are
characterised by problems with mood control and the psychotic episodes
appear associated with disturbances in mood, and patients will often
have periods of normal functioning between psychotic episodes even
without medication. Schizophrenia is characterized by psychotic
episodes which appear to be unrelated to disturbances in mood, and
most non-medicated patients will show signs of disturbance between
psychotic episodes.
Psychotic episodes may vary in duration between individuals. In
brief reactive psychosis, the psychotic episode is related directly
to a specific stressful life event, so patients may spontaneously
recover normal functioning within two weeks. In some rare cases,
individuals may remain in a state of full-blown psychosis for many
years, or perhaps have attenuated psychotic symptoms (such as low
intensity hallucinations) present at most times.
Patients who are undergoing a brief psychotic episode may have
many of the same symptoms as a person who is psychotic as a result
of (for example) schizophrenia, and this fact has been used to support
the notion that psychosis is primarily a breakdown in some specific
biological system in the brain. The dopamine hypothesis of psychosis
was an early, and still popular, example of a theory based on this
assumption. However, it is controversial how much weight should
be given to such exclusively biological theories as it has become
clearer that a wide range of influences (including environmental,
social and childhood development factors) may contribute to the
final experience of psychosis.
It has also been argued that psychosis exists on a continuum as
everybody may have some unusual and potentially reality-distorting
experiences in their life. This has been backed up by research showing
that experiences such as hallucinations have been experienced by
large numbers of the population who may never be impaired or even
distressed by their experiences10. In this view, people who are
diagnosed with a psychotic illness may simply be one end of a spectrum
where the experiences become particularly intense or distressing
(see schizotypy).
Psychosis and brain function
The first brain image of person with psychosis was completed as
far back as 1935 using a technique called pneumoencephalography1
(a painful and now obsolete procedure where cerebrospinal fluid
is drained from around the brain and replaced with air to allow
the structure of the brain to show up more clearly on an X-ray picture).
Pneumo-encephalogram of person with psychosis, 1935Modern brain
imaging studies, investigating both changes in brain structure and
changes in brain function of people undergoing psychotic episodes,
have shown mixed results.
A 2003 study investigating structural changes in the brains of
people with psychosis showed there was significant grey matter reduction
in the cortex of people before and after they became psychotic2.
Findings such as these have led to debate about whether psychosis
is itself neurotoxic and whether potentially damaging changes to
the brain are related to the length of psychotic episode. Recent
research has suggested that this is not the case3 although further
investigation is still ongoing.
Functional brain scans have revealed that the areas of the brain
that reacts to sensory perceptions are active during psychosis.
For example, a PET or fMRI scan of a person who claims to be hearing
voices may show activation in the auditory cortex, or parts of the
brain involved in the perception and understanding of speech.
On the other hand, there is not a clear enough psychological definition
of belief to make a comparison between different people particularly
valid. Brain imaging studies on delusions have typically relied
on correlations of brain activation patterns with the presence of
delusional beliefs.
One clear finding is that persons with a tendency to have psychotic
experiences seem to show increased activation in the right hemisphere
of the brain4. This increased level of right hemisphere activation
has also been found in healthy people who have high levels of paranormal
beliefs5 or in people who report mystical experiences6. It also
seems to be the case that people who are more creative are also
more likely to show a similar pattern of brain activation7. Some
researchers have been quick to point out that this in no way suggests
that paranormal, mystical or creative experiences are in any way
by themselves a symptom of mental illness, as it is still not clear
what makes some such experiences beneficial whilst others lead to
the impairment or distress of diagnosable mental pathology. However,
people who have profoundly different experiences of reality or hold
unusual views or opinions have traditionally held a complex role
in society, with some being viewed as kooks, whilst others are lauded
as prophets or visionaries.
Psychosis has been traditionally linked to the neurotransmitter
dopamine. In particular, the dopamine hypothesis of psychosis has
been influential and states that psychosis results from an overactivity
of dopamine function in the brain, particularly in the mesolimbic
pathway. The two major sources of evidence given to support this
theory are that dopamine-blocking drugs (i.e. antipsychotics) tend
to reduce the intensity of psychotic symptoms, and that drugs which
boost dopamine activity (such as amphetamine and cocaine) can trigger
psychosis in some people (see amphetamine psychosis).
Nevertheless, the connection between dopamine and psychosis is
generally believed to be complex. First of all, while antipsychotic
drugs immediately block dopamine receptors, they usually take a
week or two to reduce the symptoms of psychosis. Moreover, newer
and equally as effective antipsychotic drugs actually block slightly
less dopamine in the brain than older drugs whilst also affecting
serotonin function, suggesting the 'dopamine hypothesis' is vastly
oversimplified.
Psychiatrist David Healy has criticised pharmaceutical companies
for promoting simplified biological theories of mental illness that
seem to imply the primacy of pharmaceutical treatments while ignoring
social and developmental factors which are known to be important
influences in the aetiology of psychosis8.
Some theories regard many psychotic symptoms to be a problem with
the perception of ownership of internally generated thoughts and
experiences9. For example, the experience of hearing voices may
arise from internally generated speech that is mislabelled by the
psychotic person as coming from an external source.
Cannabis and psychosis
There is now growing evidence for a small but significant link
between cannabis use and vulnerability to psychosis11. Some studies
indicate that cannabis use correlates with a slight increase in
psychotic experience, which may trigger full-blown psychosis in
some people. Early studies have been criticized for failing to consider
other drugs (such as LSD) that the participants may also have used
before or during the study, as well as other factors such as possible
pre-existing mental health issues. However, more recent studies
with better controls have still found a small increase in risk for
psychosis in cannabis users. It is still not clear whether this
is a causal link, and it may be that cannabis use only increases
the chance of psychosis in people already predisposed to it. The
fact that cannabis use has increased over the past few decades,
whereas the rate of psychosis has not, suggests that a direct causal
link is unlikely for all users.
Non-psychiatric conditions and psychosis
Psychosis can be a feature of several diseases, often when the
brain or nervous system is directly affected. However, the fact
that psychosis can occasionally arise in parallel with a number
of ailments (including diseases such as flu or mumps for example)
suggests that a variety of nervous system stressors can lead to
a psychotic reaction. Psychosis arising from non-psychiatric conditions
is sometimes known as 'secondary psychosis'. The mechanisms by which
this happens is still not clear, but the non-specificity of psychosis
has led Tsuang and colleagues to argue that "psychosis is the
'fever' of mental illness—a serious but nonspecific indicator"12.
There are some non-psychiatric conditions which are linked particularly
to psychosis, which may include:
- Brain tumour
- Dementia with Lewy bodies
- Hypoglycemia
- Intoxication
- Multiple sclerosis
- Systemic Lupus Erythematosus (it is one of the 19 types of nervous
system involvement in SLE).
- Sarcoidosis
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