1.1

Diagnostic assessment is the process of appraising a patient's condition. It involves effectively engaging the patient in order to obtain accurate information relevant to understanding health problems (mental and general medical disorders), their context (psychosocial and environmental problems) and their impact on adaptive functioning and participation in society (disablements). A comprehensive diagnostic formulation represents a summary of the clinician's judgement about the overall condition of the patient, obtained as much as possible with the latter's collaboration. The main purpose of diagnosis is to serve as the basis for clinical care. Further objectives include to communicate concisely and reliably information on health problems, to understand their biopsychosocial pathogenesis and the interaction of internal and contextual factors, to enhance training and research, and — last but not least — to inform a collaborative process of care aimed at the restoration and promotion of health, functioning and quality of life (Fig. 1.1).

Fig. 1.1. Overview of the comprehensive diagnostic assessment process.

1.2

A mental disorder is conceived in these guidelines as a recognisable set of clinical symptoms and behaviours associated in the majority of cases with suffering, psychic disharmony, and interference with adaptive functioning and participation in social life. This concept is incorporated in standard classifications of mental disorders, such as the chapter on mental and behavioural disorders of the World Health Organization's International Classification of Diseases and Related Health Problems (ICD—10) and other international classifications based upon it.

1.3

Other concepts integral to a comprehensive diagnostic formulation include the following.

1. (a) General medical conditions — health problems that are not classified as mental or behavioural disorders. General medical conditions may have emotional components, and mental disorders may have somatic elements.

2. (b) Disabilities — limitations or problems in adaptive functioning. Such limitations occur in self-care, interpersonal functioning, occupational performance and participation in society.

3. (c) Psychosocial and environmental problems — contextual factors or situations affecting the emergence or course of illness and requiring clinical attention and intervention.

1.4

A comprehensive diagnostic formulation and its theoretical framework, like all human constructs, are products of their time and circumstances. Therefore, the clinician should be aware that they reflect historical developments, cultural factors, ethical norms, and clinical and epidemiological requirements at a particular moment.

1.5

The psychiatric interview is the single most important part of the diagnostic evaluation process. It affords the means to establish rapport and to elucidate clinical data by listening to and questioning the patient, and observing the patient's behaviour. The interview is the main source of information on the course of the condition: the patient's personality, biography and adaptive functioning, and environmental and psychosocial stressors. It is also the basis of the idiographic (personalised) evaluation of the patient. The interview is conducted according to professionally accepted rules and ethical standards, and requires appropriate training.

1.6

The clinician must consider other sources of information besides the clinical interview. This is essential in circumstances that prevent the patient from providing information. Records of previous hospitalisations and out-patient treatment are usually important to consult. Other sources such as relatives, friends, neighbours and police should be consulted whenever appropriate, with the patient's consent and assuring confidentiality in the use of such information, as far as possible.

1.7

All patients presenting for psychiatric care should receive a comprehensive evaluation of symptoms and mental state. A basic physical evaluation is advisable, including if necessary a physical examination. All psychopathological terms should be used in a reliable and comparable way, and all areas of psychopathology should be described in a systematic and standardised manner. Supplementary assessment procedures are further sources of information, ranging from specialised physical evaluation, laboratory tests and imaging procedures to structured or standardised instruments for the assessment of the clinical condition. The clinician should be familiar with them and with the prerequisites for their use.

1.8

The diagnostic process involves more than identifying a disorder. Positive aspects of health, such as personal and social assets and quality of life, should also be described. The diagnosis itself should combine a nomothetic or standardised diagnostic formulation (e.g. ICD-10, DSM-IV) with an idiographic (personalised) diagnostic formulation reflecting the uniqueness of the patient's personal experience. At the nomothetic level, a multi-axial diagnostic formulation is recommended. For the idiographic formulation, an integration of the perspectives of the clinician, patient and family should be presented in natural language.

1.9

The main objective of diagnosis is patient care. A care plan should be prepared on the basis of both the multi-axial formulation of the patient's condition (taking into account clinical disorders present, disablements, contextual factors and quality of life) and the idiographic diagnostic formulation (e.g. the patient's needs and expectations, cultural factors and economic and therapeutic resources). The programme of care should include additional diagnostic studies and specific therapeutic interventions. Evolving longitudinal observations should lead to periodic updating of the comprehensive diagnostic formulation.

1.10

A record of information documenting the comprehensive diagnostic assessment should be kept in every individual patient's chart. This information should be presented in an organised format which includes narrative components.