Psychosis closely corresponds to the general public's idea of "madness", and essentially involves loss of contact with reality—believing things that are not true and/or experiencing things that are not there.
Sometimes referred to as "the fever of psychiatry," psychosis can occur in a number of psychiatric conditions, most notably, schizophrenia, mania (bipolar disorder), severe depression, delirium, and drug intoxication. It can also result from stress or trauma.
The oldest extant description of a psychotic illness is contained in the Ebers papyrus, which goes back to the Egypt of 1550 BCE. And archeological finds of Stone Age skulls with burr holes—drilled, presumably, to release evil spirits—have led to speculation that psychosis is as old as mankind itself.
Psychosis can consist of delusions, hallucinations, or a combination of both.
A delusion can be defined as "a strongly held belief that is not amenable to logic or persuasion and that is out of keeping with its holder’s background or culture." Although delusions need not be false, the process by which they are arrived at is usually bizarre and illogical.
In psychotic depression, for example, delusions are commonly along the themes of guilt or poverty. Delusions of guilt involve the belief that one has committed a crime or sinned greatly, for instance, by being personally responsible for a recent earthquake or terrorist attack. Delusions of poverty involve the belief that one is being, or has been, ruined, for instance, by being defrauded by a relative or pursued by a horde of creditors.
Delusions in depression can also take on ‘nihilistic’ overtones. Nihil in Latin means "nothing", and nihilistic delusions involve the belief that one is about to be reduced to nothing, that is, to die or suffer a personal catastrophe, or even that one is already dead.
Cotard’s syndrome is the combination of nihilistic delusions with somatic delusions, that is, delusions about the body. A person with Cotard’s syndrome might believe, for instance, that her guts are putrefying, or that she has lost all her blood or internal organs.
Paranoid delusions, religious delusions, and delusions on other themes are also possible.
A hallucination can be defined as "a sense perception arising in the absence of an external stimulus". Hallucinations involve hearing, seeing, smelling, tasting, or feeling things that are not actually there.
The most common hallucinations are auditory, involving sounds or, more usually, voices. The person may hear one or several voices, either talking to her (second-person—"you"— voices) or about her (third-person—"she"—voices). The voices are often mocking or attacking, seeking to undermine the person’s self-esteem or entrench feelings of guilt or hopelessness.
Voices that order the person to do certain things are called "command hallucinations". These can be especially dangerous, if, for example, they are goading the person to harm herself.
Voices can be highly distressing, especially if they involve threats or abuse, or if they are loud and incessant. However, not all voices are distressing, and some, such as the voices of old acquaintances, dead ancestors, or guardian angels, might even be a source of comfort or reassurance.
I discuss delusions and hallucinations and psychosis in general at much greater length in my book The Meaning of Madness.
As I said, psychosis closely corresponds to the general public’s idea of "madness".
Feelings of fear and anxiety towards people with psychosis are often reinforced by selective reporting in the media of the rare headline tragedies involving people with (usually untreated) mental illness, most often schizophrenia.
But the reality is that most people with psychosis are no more dangerous than you or me. On the contrary, they are distressed and vulnerable, and far more likely to pose a risk to themselves than to others, whether through self-harm, neglect, accident, or openness to exploitation.
If you or someone you know may be suffering with psychosis, it is very important to seek help early. This can at times be difficult insofar as the person with psychosis may not recognize that they are ill. But with the right and timely support, most people with psychosis are able to make a full recovery.
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