Psychopathology is the systematic study of abnormal experience, cognition, and behaviour. It includes the explanatory psychopathologies, where there are assumed causative factors according to theoretical constructs, and descriptive psychopathology, which precisely describes and categorizes abnormal experiences as recounted by the patient and observed in his behaviour.⁽¹⁾ Therefore the two components of descriptive psychopathology are the observation of behaviour and the empathic assessment of subjective experience. The latter is referred to by Jaspers as phenomenology,⁽²⁾ and implies that the patient is able to introspect and describe what these internal experiences are, and the doctor responds by recognizing and understanding this description. Descriptive phenomenology, as described here, is synonymous with phenomenological psychopathology, and involves the observation and categorization of abnormal psychological events, the internal experiences of the patient, and consequent behaviour. The attempt is made to observe and understand this psychological event or phenomenon so that the observer can, as far as possible, know what the patient’s experience must feel like.

It is not surprising that the identification and classification of the phenomena of mental illness is a difficult task as there is no consensus concerning what would be acceptable as normal healthy experiences. Mental illness has variously been considered as the products of a diseased brain, the symptoms that doctors treat, or a statistical variation from the norm carrying biological disadvantage, and mental illness often has legal implications. It is best to retain the use of the word ‘normal’ in a statistical sense; thus a phenomenon, such as hypnagogic hallucination, may be statistically abnormal but not an indicator of ill health or mental disease. Similarly, it is unwise to extrapolate from a population of mentally ill people and make assertions about the origins of behaviour in those who are not mentally ill.

It is important to recognize the effect of culture on subjective experience, the expression of psychological symptoms, and their manifestation in behaviour. In some cultures the very expression of subjective experience and emotion is discouraged and censored, in others feelings tend to be somatized, and in yet others the subjective experience of the individual tends to be subjugated to the sense of well being of the immediate social group. There are specific culture-bound expressions of subjective distress concerning body image in those who suffer from anxiety disorders. For delusions of passivity, although the psychopathological form remains relatively constant, the description of content will vary according to culture; for example, ‘the djinn made me do it’, ‘my thoughts are controlled by the television’. Similarly, for possession state, although the psychopathological description remains similar, the actual cultural expression is very different between a member of a fundamentalist sect in the American Appalachian Mountains and a Buddhist girl in Sri Lanka.

Although in internal medicine a clear distinction is made between symptom (the complaint which the patient makes) and sign (the indicator of specific disease observed or elicited on examination), in psychiatry both are contained within the speech of the patient. He complains about his unpleasant mood state, therefore identifying the symptom; he ascribes the cause of the pain in his knee to alien forces outside himself, thus revealing a sign of psychotic illness. Because both symptoms and signs emanate from the patient’s conversation, in psychiatric practice the term symptom is often used to include both. For a symptom to be used diagnostically, its occurrence must be typical of that condition and it must occur relatively frequently.

Fundamental to psychiatric examination is the use of empathic understanding to explore and clarify the patient’s subjective experiences. The method of empathy implies using the ability to ‘feel oneself into’ the situation of the other by proceeding through an organized series of questions, rephrasing, and reiterating where necessary until one is quite sure of what is being described by the patient. The final stage is recounting back to the patient what you, the psychiatrist, believe the patient’s experience to be, and the patient recognizing that as indeed an accurate representation of their own internal state. Empathy uses the psychiatrist’s capacity, as a fellow human being, to experience what the patient’s subjective state must feel like as it arises from a combination of external environmental and internal personal circumstances.

Identifying phenomena as specific indicators of defined psychopathology may be difficult. It may require hearing much conversation from the patient for significant words and sentences to be revealed. The psychiatrist, when in the role of psychopathologist, has to assume that all speech of the patient, all behaviour of the patient, and every nuance has meaning, at least to the patient at the time the speech or behaviour takes place; it is not just an epiphenomenon of brain functioning.

Jaspers has contrasted understanding with explaining; descriptive phenomenology is concerned with the former. Understanding is the perception of personal meaning of the patient’s subjective experience and involves the human capacity for empathy. That is, I understand because I am able to put myself into my patient’s situation and know for myself how he is feeling, I feel those feelings of misery myself. Explanation is concerned with observation from outside and working out causal connections as in scientific method. In psychopathology, the terms primary and secondary are based upon this important distinction between meaningful and causal connections. That which is primary can be reduced no further by understanding, i.e. by empathy. What is secondary emerges from the primary in a way which can be understood by putting oneself into the patient’s situation at the time; that is, if I were as profoundly depressed as my patient, I could have such a bleak feeling that I believed the world had come to an end—a nihilistic secondary delusion.

Within certain limits subjective experience is both predictive and quantifiable. When an individual loses a close relative it can be predicted that he or she will experience misery and loss. It is possible to quantify depressive symptoms and compare the degree of depression at different times in the same individual or differences between individuals at the same time. An important distinction for psychopathology is that between form and content. The form of psychological experience is the description of its structure in phenomenological terms (e.g. a delusion). Its content is the psychosocial environmental context within which the patient describes this abnormal form: ‘Nurses are coming into the house and stealing my money’. The form is dependent upon the nature of the mental illness, and ultimately upon whatever are the aetiological factors of that condition. Content is dependent upon the life situation, culture, and society within which the patient exists. The distinction is important for diagnosis and treatment; determining the psychopathological form is necessary for accurate diagnosis, whereas demonstrating the patient’s current significant concerns from the content of symptoms will be helpful in constructing a well-directed treatment regime.

Whereas most science is concerned with objectivity and with trying to eliminate the observer as far as possible from being a variable within the experiment, descriptive phenomenology tries to make evaluation of the subjective both quantifiable and scientific. It is a mistake to discredit subjectivity in our clinical practice. Inevitably we use it all the time and we should learn to use it skilfully and reliably. When I make an assessment that my patient is depressed, I am, at least to some extent, making a subjective judgement based upon the experienced and disciplined use of empathy: ‘If I felt as my patient looks and describes himself to be, I would be feeling sad’. In psychopathology the distinction is also made between development, where a change of thinking or behaviour can be seen as emerging from previous patterns by understanding what the individual’s subjective experience is, and process, where an event is imposed from outside and this cannot be understood in terms of a natural progression from the previous state. Anxiety symptoms could be seen as a development in a person with anankastic personality confronted with entirely new external circumstances; epilepsy and its psychiatric symptoms would be a process imposed upon the individual and not understandable in terms of previous life history.

There are important theoretical differences from dynamic psychopathology. Descriptive psychopathology does not propose explanations accounting for subjective experience or behaviour, but simply observes and describes them. Psychoanalytic psychopathology studies the roots of current behaviour and conscious experience through postulated unconscious conflicts and understands abnormalities in terms of previously described theoretical processes. The distinction between form and content and between process and development is not seen as important in psychoanalysis, but symptoms are considered to have an unconscious psychological basis. Descriptive phenomenology makes no comment upon the unconscious mind. It depends upon the subject being able to describe internal experiences, i.e. conscious material. Descriptive psychopathology is not dependent upon brain localization but on clarifying the nature of the subjective phenomena in discussion with the patient; if links can then be shown between certain phenomena and specific brain lesions, that is, of course, highly advantageous in furthering psychiatric knowledge. Descriptive phenomenology can be a unifying factor between concepts of brain and mind; it does not depend on philosophical stance on the nature of mind or brain.

Cutting⁽⁴⁾ defines hallucination as ‘perception without an object or as the appearance of an individual thing in the world without any corresponding material event’. The problem with this definition is that although some hallucinating patients mistake a hallucinatory perception for a real one, others can differentiate them: as demonstrated experimentally by Zucker,⁽⁵⁾ there is an ‘as if’ quality even when patients assert that they perceive real objects or events. Voices described in detail by hallucinating patients were imitated and presented to the patients without warning. They had no difficulty in discriminating these external voices from their hallucinations. For this reason Janzarik⁽⁶⁾ defined hallucinations, without associating them with perception at all, as ‘free running psychic contents’ (using a concept similar to Jackson’s disinhibition). In keeping with this idea, lack of perception may facilitate hallucinations as in sensory deprivation or in the oneiroid states of paraplegic patients.⁽⁷⁾

The perceptual quality of hallucinations differs from similarity to sensory experiences, as in delirium, to the bizarre apprehensions of some with schizophrenia. Also, the extent to which the person is affected varies from descriptions of hallucinations as film-like in amphetamine psychoses to the affectively overwhelming experiences of hallucinations associated with delusional mood.

The term pseudohallucination, sometimes, is used to describe a perception recognized as unreal. Jaspers⁽⁸⁾ defined hallucination as corporeal and tangible; pseudohallucination lacks this quality. According to Jaspers, pseudohallucinations are not tangible and real as hallucinatory perceptions; they appear spontaneously; they are discernible from real perception; and, they are difficult, but not impossible, to overcome voluntarily. Kandinsky illustrated Jaspers’ definition of pseudohallucination: spontaneously arising images of acquaintances arose when a patient kept his eyes closed. He was fully aware of the unrealistic character of this experience and could abandon it by opening his eyes. Thus, to Jaspers, pseudohallucinations are close to imagined images except that they arise spontaneously and are more vivid. Jaspers’ definition is not used consistently; in some Anglo-American literature it has been sufficient for the definition of pseudohallucination that there be subjective awareness that the percept lacks a real external equivalent and arises from the subject.

Imagery describes vivid visual experiences, which can be produced and manipulated voluntarily. It occurs in trance states when the perceptions are produced voluntarily, but are more real and last longer than in a normal state.

Illusions differ from hallucinations in being based on a misinterpretation of a real object or event, often associated with a mood. Illusions have to be distinguished from delusional perceptions which are percepts based on real objects to which an incorrect meaning has been attached. In delusional perceptions this ‘error’ cannot be corrected by the patient; in illusions the patient can recognize the true meaning.

Kurt Schneider described Gedankenlautwerden (écho de la pensée, or thoughts heard aloud) as a transitional phenomenon between vivid imagination and auditory hallucination. The patient recognizes that the words he hears are his own thoughts, but he cannot voluntarily control them. Gedankenlautwerden can disturb concentration when talking to other people. It can be differentiated from thought insertion and from auditory hallucinations in that there is a lesser degree of alienation.

Klosterkötter⁽⁹⁾ has described transitions from elementary unformed hallucinatory sensations, like a crack, bump, or hiss, through more meaningful perceptions which still can be localized ‘inside’ the head, to complex hallucinations which become part of a delusional cognitive structure. These transitions were related to increasingly affective involvement in the themes of the hallucination. Klosterkötter’s observations support Janzarik’s interpretation of hallucinations as ‘free running psychic contents’, as do experimental studies of model psychoses which show a regular sequence of three psychopathological states: vegetative arousal, affective change, and ‘productive’ phenomena-like hallucinations and delusions.

Some misperceptions, found mainly in schizophrenic patients, are less complex than hallucinations, appear to be more closely related to neuropsychological disturbances, and include less systematization. They include optical distortions of size, colour, distance, and perspective, which can resemble experiences reported by people taking cannabis or other psychoactive drugs. These fluctuating, circumscribed misperceptions exemplify the way in which a more complex phenomenon of psychopathology can be built upon something more basic. Krause et al.⁽¹⁰⁾ videotaped the non-verbal behaviour of schizophrenic patients and their healthy partners in a conversation. Brief non-verbal cues play an important part in dialogue. Schizophrenic patients miss these non-verbal brief cues and are poor at judging the intentions of others; their own non-verbal communication is poorly co-ordinated. The ensuing dysfunction diminishes social competence. Schizophrenic painters, trained before the onset of their illness, have been shown to misperceive perspective.⁽¹¹⁾

Hallucinations can affect every sense modality. The most common, in the idiopathic psychoses, are auditory hallucinations, usually in the form of voices, although other kinds of sound may be associated with delusional contents. Voices talking to each other about the patient, and voices commenting about the patient’s ongoing acting or thinking, are considered to be typical of, but not specific to, schizophrenia.⁽¹²⁾ Voices calling the patient’s name or talking without comments to the patient are diagnostically non-specific.

Visual hallucinations are most frequently found in organic psychosis, particularly delirium, in which they may occur for only a couple of hours during the night if the syndrome is not full blown. Visual hallucinations, more often than those in other sensory modalities, depict animals and scenes with several persons. In alcoholic delirium in particular, optical hallucinations of fine structures (such as hairs, threads, or spider webs) occur, and are especially likely to appear if the patient stares at a white wall. A typical, although not specific, combination of hallucination and delusion in organic psychosis is the ‘siege experience’, in which
patients believe they are besieged by enemies and have to bar their doors and windows.

Bodily, tactile, or coenaesthetic hallucinations are associated more often with schizophrenia than with affective or organic psychoses. The phenomenology includes simple tactile sensations of the skin, sexual sensations, sensations of the contraction, expansion, or rotation of inner organs, or atypical pain. Usually these sensations are associated with delusional explanations. Tactile hallucinations localized in the skin can underlie the delusion of parasitosis. Elderly patients in the early stages of organic cerebral alterations are at highest risk.

Coenaesthesia is a bodily misperception, which may last for minutes to days. It fluctuates (sometimes in relation to stress), and is usually not attributed to external agents or explained by delusional ideas. Patients seldom report them spontaneously. Klosterkötter⁽⁹⁾ suggests that when coenaesthesia is attributed strongly to external influences, it is likely to be followed by schizophrenia.

Hallucinations may be gustatory or olfactory, for example, a smell of gas (perhaps thought to emanate from neighbours trying to kill the patient). Blunting of gustatory sensations or misperception of food as oversalted or overspiced is occasionally reported by melancholic patients.

Aetiological theories are of three kinds:

The work of Penfield and Perot⁽¹³⁾ has suggested that overstimulation may be a pathogenic mechanism. They stimulated the temporal regions of 500 patients, of whom 8 per cent reported scenic hallucinations, some in several modalities. Stimulation of the visual occipital cortex led to simple hallucinations-like flashes, circles, stars, or lines. This phenomenon has been observed in drug-induced experimental psychosis. It is interesting that schizophrenic patients can usually distinguish drug-induced hallucinations from those arising from their disorder. Using neural network theories, Emrich⁽¹⁴⁾ simulated hallucinations by using Hopfield networks; overloading the storage capacity of the network generated what appeared to be the equivalent of hallucinations.

Disinhibition theory originated with Hughlings Jackson, who considered that productive symptoms were caused by the disinhibition of controlling neural activities, while negative symptoms resulted from damage to the systems, which generate the productive symptoms. More recently, sensory deprivation research has yielded inconsistent results; hallucinations, narrowly defined, seldom occur after deprivation, which may be of greater relevance to vivid, usually visual, imaginative experiences. Disinhibition may also underlie the ‘hypnagogic hallucinations’ which can occur in healthy subjects shortly before they fall asleep.

The role in the production of hallucinations of post-sensory interpretation and evaluation of stimuli is uncertain. In these terms, hallucinations are a sort of deception, but this is not a sufficient description of their nature. Recent neurophysiological hypotheses and findings from neuroimaging studies have suggested that there is an ‘inner censorship’ involved in clarifying ambiguities of perception.⁽¹⁴⁾

Three types of thinking can be distinguished which represent a continuum, without sharp boundaries, and intertwined in everyday life, from low to high regard for external reality and goaldirectness: fantasy thinking, imaginative thinking, and rational thinking.⁽¹⁵⁾ Since each of these types can predominate under some conditions, this distinction is useful to understand certain abnormal phenomena.

Fantasy thinking (also called dereistic or autistic thinking) produces ideas, which have no external reality. This process can be completely non-goal-directed, even if the subject is to some extent aware of the mood, affect, or drive, which motivates it. In other cases fantasy serves to exclude reality, which may require material with which the subject does not want to engage. This type of fantasy thinking is directed. Its goal is not to solve a problem but to avoid it via neglect, denial, or distortion of reality. Normal subjects use fantasy thinking deliberately and sporadically. However, if its content becomes subjectively accepted as fact, it becomes abnormal. This pathological exclusion of reality can remain limited in extent (e.g. in hysterical conversion and dissociation, pseudologia phantastica, and some delusions) or it may be manifested as withdrawal from the real world.

Rational (conceptual) thinking attempts to resolve a problem through the use of logic, excluding fantasy. The accuracy of this endeavour depends on the person’s intelligence, which can be affected by various disturbances of the different components involved in understanding and reasoning.

Imaginative thinking comes between fantasy thinking and rational thinking. It is a process of forming a representation of an object or a situation using fantasy but without going beyond the rational and possible. This thinking is goal-directed but frequently leads to more general plans than the solution of immediate problems. Imaginative thinking becomes pathological if the person attaches more weight to his representation of events than to other objectively equally possible interpretations. In overvalued ideas, the imagined interpretation surpasses other interpretations in strength; in delusions, all other possibilities are excluded.

The term ‘delusion’ signifies a complex edifice of thinking in which ‘delusional ideas’ are linked with other (‘normal’) thoughts. Delusions are communicated to others in the form of judgement. In this context, the term ‘delusional idea’ customarily refers to pathologically false judgement for which three criteria have been proposed: the unrivalled conviction with which they are held, their lack of amenability to experiences or compelling counter-arguments, and the impossibility of their content.⁽¹⁶⁾ The last criterion must be discarded for two reasons. Firstly, collective beliefs derived from the socio-cultural setting of a person can be considered, in other surroundings, as false or impossible. Taking this into account, delusion is often defined as a ‘false unshakable belief, which is out of keeping with the patient’s social and cultural background’.⁽¹⁵⁾ Secondly, in certain delusions (e.g. delusional jealousy) the content
does not go beyond the possible. Thus delusions are best defined as overriding, rigid, convictions which create a self-evident, private, and isolating reality requiring no proof.⁽¹⁷⁾

An overvalued idea is an acceptable, comprehensible idea pursued beyond the bounds of reason.⁽²²⁾ Overvalued idea causes disturbed functioning or suffering to the person himself or others.

Overvalued ideas of prejudice (overvalued paranoid ideas) are characterized by an underlying self-referent interpretation of the behaviour or sayings of others; patients assume themselves to be overlooked, slighted, unfairly treated, provoked, or loved. Overvalued apprehension may become apparent as morbid jealousy, hypochondriacal phobia (e.g. parasitophobia), or dysmorphophobia, in which patients assume that they attract attention because of a real or presumed bodily defect. In anorexia nervosa subjects are preoccupied by the endeavour to remain thin, and in transsexualism by the desire to change gender because they feel that they belong to the opposite sex.

Overvalued ideas generally occur with abnormal personality under stressful situations. Those with paranoid personality traits may develop, on the basis of a presumed injustice, querulous, or litiginous overvalued idea. Sometimes ideas become overvalued only during abnormal mood states (of various origins) which set aside counterbalancing influences.

The content of thought in mood disorders is coloured by affect. Negative thinking about self, the future, and the world prevails.⁽²³⁾ Mishaps and failures are attributed to personal faults; success is attributed to the action of other people. This depressive thinking spreads from the starting point of negative life events to more general events, and it tends to become long lasting. The fixed viewpoint that emerges is called ‘cognitive schema’. After recovery from an acute episode this schema may become latent, but it can be reactivated by distressing life events. It can also prolong symptoms. Negative thinking started by minor misfortunes can become autonomous, driving down mood—which in turn intensifies negative thinking. The negative schema can prolong a depressive episode or precipitate a new one. It is probable that such schemas are activated by both cognitions and emotions. Guilty thoughts are closely connected with this type of thinking, and may reach the intensity of a delusion. To a degree, guilty thinking in depression is dependent on culture. In mania, the content of thought is related to the mood of elation, with diminished self-criticism and excessive self-importance. In phobic and other anxiety states, thinking centres on situations leading to anxiety. Typical contents of delusional thinking in depression concern guilt, religious failure, condemnation, personal insufficiency, impoverishment, hypochondriasis, and nihilistic ideas. In mania, delusional ideas may be feelings of spiritual or economic power. In contrast with schizophrenic delusions, affective delusions grow out of the underlying, excessive mood and do not appear as something new and alien to the personality.

Phobic and anankastic (obsessional) phenomena have in common that the patient experiences them as unwanted, but cannot suppress them. They often occur together.