1.1 What is psychosis?
Psychiatry has always struggled with terms and definitions. Canvass the opinions of a modern community multidisciplinary team, and there are likely to be a range of opinions on what psychosis actually is [1]. Yet very few will object to the phenomenological perspective, which captures the seriousness of just what is at stake in psychosis. That is because psychosis impacts upon the highest and most personal faculties of the human mind.
In short, psychosis describes a disturbance of perception, thinking, beliefs, or selfhood in which the patient experiences a fundamental transformation in their experience of lived reality. This transformation can be terrifying as in paranoid psychoses or thrilling as in mania. Psychosis can emerge and dissipate quickly or become ingrained in the mind/brain over many months. Some patients seek safety by withdrawing from the world, whereas others attract attention to their mental state through excited, agitated, bizarre, or catatonic behaviour.
1.2 Lack of insight
The most common feature of psychosis is not hallucinations, delusions, thought disorder, paranoia or suspiciousness as is commonly believed but lack of insight [2]. Lack of insight denotes the blindâspot a patient has in regard to the falseness of their new reality and the abnormal nature of their mental state [3]. For some the term âlack of insightâ exemplifies the power imbalance within psychiatry.
Regardless of terminology, the blindâspot is what makes the care of many patients suffering psychosis particularly challenging. Why would anyone take treatment, let alone engage with mental health professionals if they think their experiences are real rather than a manifestation of psychiatric illness.
1.3 Causes of psychosis
Mental states have material correlates. For some patients, a material dysfunction is the direct cause of their psychosis. The list of causes includes endocrine disorders (e.g. thyroid disease), metabolic disorders (e.g. porphyria), autoâimmune conditions (e.g. NâmethylâDâaspartate, NMDAâreceptor encephalitis), infections (e.g. herpesâsimplex encephalitis), epilepsy (e.g. temporal lobe epilepsy), nutritional deficits (e.g. vitamin B12 deficiency), basal ganglia disorders (e.g. Wilson's disease), medications (e.g. acyclovir), dementias (e.g. Alzheimer's disease), and most common of all, psychoactive drugs, as causes [4].
- The following psychoactive drugs can elicit an acute psychotic episode after a single administration: serotonin 5HT2A receptor agonists (e.g. lysergic acid diethylamide, LSD), glutamate NMDA channel blockers (e.g. ketamine), and cannabinoid CB1 receptor agonists (e.g. deltaâ9âtetrahydrocannabinol, THC) [5].
- Repeated, heavy use of stimulants can elicit a classic paranoid psychosis by impacting upon dopamine signalling (e.g. methamphetamine) [5, 6].
Psychosis can occur in the following syndromes: schizophrenia, delusional disorder, bipolar disorder, postâpartum psychosis, schizoaffective disorder, and depression. Psychotic experiences can also manifest in severe obsessive compulsive disorder (OCD). There are also brief, acute, fullâblown psychotic episodes occurring outwith any of these syndromes, which even in the era before antipsychotic drugs, tended to show a full recovery of insight and restoration of the former reality [7, 8].
Auditory pseudoâhallucinations and âparanoiaâ can occur in people prone to emotional instability, but insight is maintained, and the prominence of deliberate selfâharm in the context of early abuse steers the formulation away from a psychotic disorder [9â11]. Indeed, psychoticâlike phenomena including voices and paranoia occur in the general population, but such experiences do not overwhelm the self to the extent that there is a fundamental transformation of lived reality, and should not be overâpsychologised as markers of mental illness [12â14].
- Robin Murray and Jim van Os have made the elegant observation that, âthe boundaries between normal mentation, common mental disorder and schizophrenia become blurred, if positive psychotic symptoms are used as a distinguisherâ [15].
Precise diagnosis might not be possible, but in some cases it is vital. For instance, psychosis arising from antibodies targeting the NMDAâreceptor requires urgent immunological treatment [16]. In such cases antipsychotics and psychological therapy are of no value and lead to delays.
Given the multitude of causes of psychosis, patients require a skilled assessment and careful biopsychosocial formulation before treatment, whether pharmacological or psychological, is embarked upon [17].
1.4 Schizophrenia: loss of personality and psychosocial decline
Psychosis and schizophrenia are not synonymous. Only about one in eight patients who experience an acute psychosis will go on to develop schizophrenia over a period of three to five years [18].
Schizophrenia is not a single syndrome [19]. From the outset, the term subsumed a collection of phenotypes [20â22].
- Paranoid form, dominated by psychotic symptoms.
- Hebephrenic form, dominated by severe thought disorder and bizarre affect.
- Catatonic form, dominated by psychomotor signs.
- Simple form, dominated by severe psychosocial decline but no psychotic symptoms.
The precise definition and demarcation of schizophrenia is as uncertain as ever, and some authorities have suggested dropping the term altogether because of the associated stigma [23, 24].
On the other hand, there are a proportion of patients who exhibit such marked social decline and loss of personality for whom no alternative descriptor is forthcoming.
- Many consider that psychosocial decline and loss of personality are the hallmarks of schizophrenia [25]. Essentially the same meaning is conveyed by the term, negative symptoms, originally formulated in nineteenthâcentury neurology to describe the loss of a function which is normally present in health. In schizophrenia the loss encompasses; drive, motivation, ambiti...
