Psychosis

Psychosis is a condition characterised by the loss of contact with reality. This is problematic because the loss of contact with reality may cause the patient to harm themselves or others, either directly or indirectly. Psychosis can be seen in many psychiatric disorders, but it's a symptom of an underlying cause, and not a disorder in itself.

In practice, psychosis manifests as delusions, hallucinations, or thought disorganisation.

Etiology

The most common cause of psychosis is schizophrenia and schizophrenia-related disorders (like schizoaffective disorder, schizophreniform disorder, delusional disorder). Other common causes are:

• Bipolar disorder
• Major depression with psychotic features
• Substance use
• Medical (organic) conditions (usually as part of delirium)

Delusions

Delusions are defined as false beliefs based on incorrect inference about reality, not consistent with the patient’s intelligence and cultural background, which cannot be corrected by reasoning. More informally, a person is delusional if they strongly believe something is true when it's in fact false, and it's impossible to change their mind.

Delusions can be non-bizarre (theoretically possible, yet untrue), or bizarre (theoretically impossible). Examples of non-bizarre delusions are "a bike gang is after me", while bizarre delusions take the shape of "aliens have replaced my brain with a machine". The delusion of pregnancy can be either bizarre or non-bizarre depending on the sex and uterus status of the person.

There are many types or "themes" of delusions. The most frequently encountered types are:

Persecutory delusions

Persecutory delusions are the most common form of delusion. They are characterised by the delusion of that theyersecuted, spied on, or followed. This can make the person paranoid. Examples of this delusion include:

• "My neighbour is constantly spying on me using wiretapping equipment"
• "There are cameras hidden in the lightswitches of every room"

Grandiose delusions

Grandiose delusions are characterised by a person holding the delusion that they have amazing knowledge, power, or worth, or believing that they’re a famous person or higher power like god. Examples:

• "I'm friends with the president of the USA"
• "I'm on my way to the police station to meet my friend Chris Brown"
• "I'm Jesus, the Messiah"

Somatic/hypochondrical

Somatic or hypochondrical delusions are characterised by a person holding the delusion that they have a certain medical condition. Examples:

• "I have a viral infection in the hair follicles of my scalp"
• "I have cancer in my stomach"

Erotomanic

Erotomanic delusions are characterised by a person holding the delusion that a certain person is deeply in love with them.

Jealousy

Also called "Othello syndrome", delusions of jealousy are characterised by a person holding the delusion that their partner is unfaithful.

Reference

Delusions of reference are characterised by a person holding the delusion that unsuspicious occurrences / meanings refer to him or her in person. The most common example is that the person believes that something said on the TV or radio refers to them in some way. Example:

• "Whenever someone mentions Syria on the television they're referring to how the IS is after me"

Other delusions

• Delusions of control - the delusion that their thoughts or actions are being controlled by others

• Thought broadcasting - the delusion that the person's thoughts are being broadcasted for others to hear
• Delusional parasitosis (Ekbom symptom) - the delusion that the person has parasites under the skin
• Fregoli delusion - the delusion that different people are in fact a single person which changes in appearance
• Capgras delusion - the delusion that a person's friend or spouse in replaced by identical-looking imposter
• Couvade delusion - the delusion that a husband experiences symptoms of pregnancy like his pregnant partner

Hallucinations

Hallucinations are false sensory perceptions without external stimuli. More informally, hallucinations are when a person percieves something that doesn't exist.

There are multiple types:

• Auditory hallucination - hearing something that doesn't exist
• Visual hallucination - seeing something that doesn't exist
• Olfactory hallucination - smelling something that doesn't exist
• Tactile hallucination - sensing touch of something that doesn't exist
• Gustatory hallucinations - tasting something that doesn't exist

Auditory hallucinations

Auditory hallucinations are the most common type of hallucination, and are suggestive of primary psychiatric illness (rather than medical). They can present as speech or simple sounds. Spoken auditory hallucinations can be commanding (telling the patient to do something), derogatory (talking shit on the patient), or threatening.

Visual hallucinations

Visual hallucinations can range from entire persons or organisms to shadows or lights. Visual hallucinations are more common in organic disorders.

Olfactory hallucinations

Olfactory hallucinations usually involve foul-smelling odours. This form of hallucination is typical for temporal lobe epilepsy.

Tactile hallucination

Tactile hallucinations are most common in substance abuse (especially cocaine) and organic disorders.

Thought disorganisation

Thought disorganisation, also called disorganised thinking or thought disorder, is a disorganized way of thinking that leads to abnormal ways of expressing language when speaking. There are many forms of this:

• Poverty of content - the patient says many words, but conveys little information with them
• Thought blocking - the patient suddenly loses their train of thought, abruptly stopping their speech
• Loosening of associations - the patient has disconnected and fragmented speech, jumping from one idea to another unrelated or indirectly related idea
• Tangentiality - the patient answers a question but progressively and increasingly diverges from the topic being asked about
• Word salad - the patient links words together incoherently, yielding nonsensical content of speech
• Perseveration - the patient repeats words or ideas persistently, even after the topic has changed

Evaluation

When assessing the patient for psychosis, anamnesis and observation during the interview is essential. Asking the proper questions increases the odds of catching the diagnosis, and obtaining collateral medical history is important.

It may be objectively evident that the patient has hallucinations during the interview, if they talk to people not in the room or stare at "nothing". Asking questions properly, like "have you ever heard sounds from people not in the room" or "have you ever seen anything which other people weren't able to see", makes the anamnesis more sensitive for hallucinations than if questions like "do you ever see things" or "have you ever heard voices in your head" are asked.

It may also be objectively evident that the patient is delusional, if they appear paranoid for example, but for the most part, one must ask the proper questions to reveal delusions. Questions like "is there anyone who is out to hurt you or monitoring you" or "do you know any famous people" may be helpful.

The presence of thought disorders will be evident during the interview, if one closely observes and takes note of the patient's speech and its contents.

Structured diagnostic interviews

Several structured diagnostic interviews are useful in the evaluation of psychosis.

Mini International Neuropsychiatric Interview for Psychotic Disorders (often called just MINI) can be used to screen for and diagnose many psychotic disorders. It's relatively brief, taking on average 15 minutes to complete.

Structured Clinical Interview for DSM disorders (SCID) is a structured diagnostic interview that can be used to assess whether the patient fulfulls diagnostic criteria for diagnoses in the DSM. The latest version is the SCID-5, and the SCID-5-CV (CV for Clinician Version) is used outside clinical trials and research.

Positive and Negative Syndrome Scale (PANSS) is used for measuring symptoms severity in psychosis.