Abreaction Abreaction is a process of vividly reliving repressed memories and emotions related to a past event. Sigmund Freud used hypnosis to rid his patients of pathological memories through abreaction. Copyright Notice Adapted from Wikipedia. Text is available under the Creative Commons Attribution-ShareAlike License 3.0 ; additional terms may apply.

Clouding of Consciousness Clouding of consciousness, sometimes called brain fog or mental fog, is a generalised impairment in higher central nervous system function. Every element of cognitive function is affected. Disorientation in time, place, and person, memory difficulties caused by failure to register and remember, aphasia, and agnosia are signs of a mental status assessment. Illusions and hallucinations are common in the visual sensory modality when perception is impaired. As a result, there is anxiety, anguish, and secondary delusions. The word 'confusion state' is occasionally used to describe a clouding of awareness, although it is misleading and should be avoided. ICD-11 Definition An impairment in the clarity of consciousness characterised by impaired ability to comprehend aspects of the environment or the self in relation to the environment, inattention, and abnormalities in thought processes, comprehension. It is typically accompanied by subjective experience of me...

Neologisms: Definition in Psychiatry and Psychology  Neologisms are senseless words or phrases whose roots are unknown (e.g., klipno for watch) and are associated with aphasia or schizophrenia. Correctly built words with comprehensible roots (e.g., headshoe for hat) are often referred to as neologisms, although they are more accurately referred to as word approximations.

Negativism: Definition in Psychiatry and Psychology  Opposition to suggestions or advice and attempts to move the subject results in the subject doing the exact opposite of what people ask of them. Behaviour that is contrary to what is appropriate in a situation or against the wishes of others, including direct opposition to attempts to move. Negativism is often a symptom of catatonia, leading to rigidity (catatonic). It differs slightly from gegenhalten, in which the person resists movement but does not make the opposite movement. 

The Doppelgänger is a phenomenon in which individuals believe that their exact "double" is always with them and follows them around.

Agnosia: Definition Loss of ability to recognize objects, persons, sounds, shapes, or smells that occur in the absence of either impairment of the specific sense or significant memory loss. 

Achromatopsia Achromatopsia refers to agnosia for colour. This term includes colour blindness. A partial or total absence of colour vision is the hallmark of achromatopsia. People with complete achromatopsia cannot perceive any colours; they see only black, white, and shades of grey. Incomplete achromatopsia is milder; it allows some colour discrimination. Other vision difficulties associated with achromatopsia include increased sensitivity to light and glare (photophobia), involuntary back-and-forth eye movements (nystagmus), and severely decreased visual acuity.  Farsightedness (hyperopia) or, less typically, nearsightedness (myopia) might affect those who are affected (myopia). During the first several months of life, these eyesight issues first appear. Achromatopsia differs from the more common forms of colour vision deficiency (also called colour blindness). People can perceive colour but have difficulty distinguishing between certain colours, such as red and green. 

Capgras Syndrome The patient believes that someone else has replaced a familiar person. Both have a close resemblance. For example, an unknown person replaces the daughter. The patient may attack the familiar person. The original name was ‘delusion des sosies’ a delusion and not a syndrome an example of reduplicative paramnesia.. the most common cause is schizophrenia. other causes include Lewy body dementia and other neuropsychiatric disorders. Always assess the risk of violence to the family person.         

Affect illusions These arise in a particular mood state. For example, a bereaved person may momentarily believe they ‘see’ the deceased person, or the delirious person in a perplexed and bewildered state may perceive the innocent gestures of others as threatening. In severe depression when delusions of guilt are present, the person believing that he is wicked may also say that he hears people talking about killing him when he is in the company of others. In these circumstances, it is difficult to know if he is experiencing illusions or hearing hallucinatory voices talking about him and attributing them to those around him.  QID: 20200407202203706