The hallmark of schizophrenia is a significant loss of contact with reality referred as psychosis.
Schizophrenia is a form of psychotic disorder.
Epidemiology
- The risk of developing schizophrenia over the course of one’s lifetime is 1%.
- 1 out of every 140 people alive today who survive until at least age 55 will develop the disorder.
This is an average lifetime risk estimate. Some people have a higher risk of developing the disorder.
- The onset is late adolescence to early adulthood, with 18 to 30 of age being the peak time but
there’re differences in men and women.
- In men the peak is 20 to 24. The incidence peak is at the same period for women but it’s less
marked (the % is lower). After age 35, number of men developing schizophrenia drops but women
developing schizophrenia have a second rise.
- Female sex hormones may be playing a role. When estrogen levels are low, psychotic symptoms in
women often get worse. This effect may explain the delayed onset (low levels in menopause).
- Men tend to have more severe forms of schizophrenia than women.
- In general, schizophrenia is more common in males with the ratio of 1,4:1.
Delusions: A delusion is a false belief that is fixed and firmly held despite clear contradictory evidence.
Involves a disturbance in the content of thought. Not all people who have delusions suffer from
schizophrenia. Still, delusions are very common in schizophrenia and occur in 90% of the patients at some
time during their illness. In schizophrenia certain types of delusions are characteristics
- one’s thought/beliefs/actions are controlled by external agents (made feelings or impulses)
- one’s private thoughts are being broadcasted (thought broadcasting)
- thoughts are being inserted into one’s brain by some external agency (thought insertion)
- some external agency has robbed one’s thoughts (though withdrawal)
- some neutral environmental event (tv, radio etc.) has personal meaning for only for person
- delusions of bodily changes (less common)
, Hallucinations: a sensory experience that seems real to person having it, but occurs in the absence of any
external perceptual stimulus (illusion is misperception of a stimulus that actually exists). Hallucinations can
occur auditory, visual, olfactory, tactile or gustatory – in any sensory modality. Auditory hallucinations are
by far the most common, they were found in 75% of patients with schizophrenia. Visuals are 39% and the
rest is even more rare. Hallucinations can even be induced the healthy people if they are under a lot of
stress and drink a lot of caffeine.
Patients can become emotionally involved in their hallucinations. People who think of themselves to be
socially inferior think the voices are more powerful than they are and act on their hallucinations and do
what the voice tell them to do. In a study, majority of patients reported that the voices spoke to them at a
normal conversational volume. Voices are often of people known to the patient in real life, or often voices
of God or the devil. Most patients report that they hear more than one voice. Mostly the voices utter rude,
vulgar, critical, bossy, or abusive.
Studies show that patients with speech hallucinations have a reduction in brain (gray matter) volume in the
left hemisphere auditory and speech perception areas. This reduced brain volume can lead to
misinterpreting own self-generated thoughts as coming from another external source. Hallucinating
patients also show increased brain activity in Broca’s area (speech production). The pattern of brain
activation that occurs when patients experience auditory hallucinations is very similar to health people
imagining there’s another person talking to them.
Disorganized speech: the external manifestation of a disorder in thought form. An affected person fails to
use language in a conventional way. This failure is not because of low intelligence or poor education. They
also refer to this as ‘cognitive slippage’ or ‘incoherence’ or ‘derailment’. In disorganized speech the words
and word combinations sound communicative but the listener is left with little to no understanding of the
speaker’s point. In some cases, completely new words appear in the speech.
Disorganized behavior: goal-directed activity is almost universally disrupted in schizophrenia. The
impairment occurs in daily functioning, work, social relations, self-care to the extent people say that
person is not himself/herself anymore. E.g. grossly disorganized behavior such as wearing gloves and scarfs
in a hot summer day. These can be attributed to the impairment of the prefrontal cortex.
Catatonia is even more striking. The patient may show a virtual absence of all movement and speech and
be in what is called catatonic stupor. At other times, patients hold an unusual posture for a long time
without showing discomfort.
Negative symptoms: 2 general symptom patterns have been differentiated.
- Positive symptoms reflect an excess or distortion in a normal repertoire of behavior and experience
such as delusions and hallucinations. Disorganized thought is also thought of in this way.
- Negative symptoms reflect an absence or deficit of behavior that are normally present. Negative
symptoms fall into 2 categories. One involved reduced expressive behavior in voice, facial
expressions, gestures or speech. This may show in blunted affect/flat affect/alogia which means
very little speech. The other involves reductions in motivation or in experience of pleasure. The
inability to persist a goal-directed activity is called avolition. Even though the patient’s negative
symptoms may seem unexpressive, they experience plenty of emotions.
Subtypes of schizophrenia:
- Paranoid schizophrenia: absurd and illogical beliefs are organized in a delusional framework (most
clinically meaningful one)
- Disorganized schizophrenia: characterized by disorganized speech & behavior and flat affect
- Catatonic schizophrenia: involves pronounced motor signs that reflect excitement
- These subtypes are not included in DSM-5 anymore
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