'Psychosis - Not Otherwise Specified' (Psychosis NOS) is a term which is used to describe psychosis that appears to be organic in nature and is not merely a part of a deeper disorder such as schizophrenia or schizoaffective disorder. Psychosis is characterised by a warped or detached sense of reality, and often manifests in delusions, hallucinations or disorganised thoughts. Patients experiencing psychosis may also become catatonic (American Psychiatric Association, 2013). The term delusion refers to a fixed belief held by the patient that is difficult to change despite the presence of evidence which directly contradicts the belief. A delusion can take many themes, and possible beliefs may include the idea that other people intend to harm the patient (persecutory delusions), that gestures or words are directed at the patient (referential delusions) or that the patient is exceptionally talented, wealthy or famous (grandiose delusions). Other types of delusions may include nihilistic, erotomanic and somatic delusions. Delusions can
17
be further classified as being bizarre if they are clearly not based in plausible reality. For example, bizarre delusions may include the belief that thoughts are being taken out of the patient's mind (thought withdrawal), or the belief that thoughts are being put in the patient's mind from an external source (thought insertion)(American Psychiatric Association, 2013).
Hallucinations are well known in pop-culture and as a result are reasonably well understood by the public at large. A hallucination can be described as any experience of the patient's perception that does not correspond with an external stimulus (American Psychiatric Association, 2013). This may involve any of the five traditionally known senses, namely sight (visual), hearing (auditory), smelling (olfactory), feeling (tactile or somatic) and tasting (gustatory). Hallucinations and delusions differ mostly in their nature: a delusion is a fixed idea that the patient believes, while a hallucination is an experience of perception. Although hallucinations can be related to any subject, religious hallucinations are extremely common. Hallucinations are normally identified through interactions of the patient with other people, as that is when the discrepancy between what is seen and what is real can be identified. A patient alone for example may not realise they are hallucinating and as a result would not identify or report the problem (Sullivan & Spooner, 2008).
Disorganised thinking typically presents as an inability of the patient to focus their thoughts or to organise what they are saying. Disorganised thought is typically identified by the patient's speech. Examples of disorganised thought include derailment (wherein a patient switches easily and frequently from one topic to another), tangentiality (wherein a patient may offer up answers to questions that are either only partially related or completely unrelated) and incoherence/word salad (wherein a patient's speech is so disorganised as to be nearly or completely incomprehensible). To be classified as disorganised thinking the symptom must be
18
severe enough that it impairs communication (American Psychiatric Association, 2013). Of particular importance in a South African context is the fact that differing first languages between the patient and the diagnosing practitioner may lead to difficulty in identification of disorganised thought.
Catatonia in the psychotic patient may be experienced to a number of degrees, from a general resistance to commands (negativism) to total lack physical or verbal responses (stupor and mutism respectively).
The above symptoms (delusions, hallucinations and disorganised thinking) collectively may be described as psychosis, though the presence of any one symptom is enough to warrant a diagnosis of psychosis, often termed 'brief psychotic disorder' or 'psychosis NOS' until more extensive criteria of other psychotic disorders are identified (American Psychiatric Association, 2013). Psychotic symptoms are generally treated with first line therapy of either a FGA or SGA. First generation antipsychotics commonly used in South Africa include haloperidol, chlorpromazine, zuclopenthixol and flupenthixol. Second generation antipsychotics commonly used include risperidone, olanzapine, and quetiapine, among others. Upon failure of the first line antipsychotic drug, an alternative antipsychotic may be used, most often from the class that was not used for first line therapy (i.e. FGA after SGA, or SGA after FGA). Should psychosis still remain refractory after trials of two or more agents, clozapine (a SGA) may be used under specific circumstances (Emsley et al., 2013). These drugs are discussed in more detail in Section 2.3.
19
2.1.1.1 Etiology of psychosis.
The development of psychosis has been linked to a number of theories over the years. Most prominent of these include theories relating to imbalances of neurotransmitters in the brain. Neurotransmitters that have been implicated include serotonin (5-HT), glutamate and dopamine (D). Of these dopamine is thought to be most significant. It has been postulated that the development of psychosis is linked to an overabundance of dopamine or to overstimulation of dopamine
receptors in the brain, primarily D2 receptors. Dopamine receptors are located
primarily in four main tracts of the brain: the nigrostriatal tract; the mesolimbic tract; the mesocortical tract; and the tubero-infundibular tract (Crismon et al., 2011). The antagonism of dopamine receptors in each of these areas can produce very different results, from precipitating movement disorders to relieving psychosis (Nord & Farde, 2011).
Other important ways in which psychosis may develop are linked to abuse of illicit substances or to worsening of certain typically non-psychiatric conditions (such as HIV/AIDs and syphilis) (Section 2.2).
2.1.1.2 Substance abuse and psychosis.
Substance abuse is a problem of extreme prevalence in South Africa. A study performed in 2010 and focusing on the treatment of substance abuse disorders in public and private settings was conducted. This study indicated that out of 8935 patients treated for substance abuse, 51% of those patients were alcohol abusers, 21% abused cannabis, 9.6% abused cocaine/crack cocaine, 7.9% abused heroin or another form of opiate, 4.5% abused methamphetamine (commonly known as tik), 2.0% abused a licit drug (i.e. a prescription or over the counter [OTC drug]) and 1.7% abused a combination of cannabis with methaqualone (otherwise known as mandrax; the combination is known colloquially as 'white pipe'). The evidence
20
identified in Ramlagan's study indicates that substance abuse is a substantial problem, particularly as these statistics only represent a small portion of all substance abusers, that is, those who have sought and received help (Ramlagan, Peltzer, & Matseke, 2010).
Substance abuse has been linked to the development of psychotic disorders, as well as the worsening of pre-existing psychotic disorders (Swartz et al., 2006; Walker & Diforio, 1997). Multiple drugs of abuse have been implicated, including cannabis, cocaine and alcohol (Green, Noordsy, Brunette, & O'Keefe, 2008). Abuse of cannabis can result in psychotic symptoms including auditory and visual hallucinations as well as delusions. While these symptoms are typically seen in acute abuse, long term addiction to cannabis is thought to be linked to time-related changes in brain structure and the development of psychotic disorders (D’Souza et al., 2005). Methamphetamine can induce symptoms of psychosis during acute use, though psychotic relapses have been seen in patients during drug-free periods, along with persistent psychosis in patients both currently using and not (Gururajan, Manning, Klug, & van den Buuse, 2012).