4.1. Normal and pathological anxiety

Anxiety can be defined as the anticipation of future harm or misfortune, accompanied by a feeling of dysphoria (unpleasantness) and/or somatic symptoms of tension. The objective of the anticipated harm may be internal or external. It is an alert signal that can warn of imminent danger and allows the person to take the necessary measures to confront a threat.

It is important to understand anxiety as a normal feeling or emotional state in response to certain situations and that it constitutes a common response to different daily stressful situations. This means that a certain degree of anxiety is even desirable for the normal treatment of day-to-day demands. Only when this exceeds a certain intensity or the person’s adaptive capacity does anxiety become pathological, causing significant discomfort with symptoms that affect the person physically, psychologically, and behaviorally (table 4).

Table 4. Symptoms of anxiety: physical and psychological

Anxiety disorders as such are a group of illnesses characterized by the presence of excessive worry, fear, tension, or activation that causes significant discomfort or a clinically significant deterioration of the activity of the individual³⁰.

The causes of anxiety disorders are not fully understood, but biological, environmental, and psycho-social factors are involved^31,32.

The biological factors include alterations in neurobiological gabaergic, and seratoninergic systems, as well as structural anomalies in the limbic system (paralimbic cortex), one of the most-affected regions of the brain. Certain physical alterations and greater frequency of usage and/or withdrawal from medicines, alcohol, drugs and/or sedatives, and other substances. Lastly, there is a certain genetic predisposition in the appearance of these disorders^33-36 .

The environmental factors include the influence of certain environmental stress agents, greater hypersensitivity, and learned response^36,37. The psychosocial risk factors for these disorders include stressful situations, family environment, threatening life experiences, and excessive worry about common subjects. The pre-disposition factors include the influence of personality characteristics³².

It appears that the interaction of multiple determining factors favors the appearance of these anxiety disorders³⁸, and comorbity with other mental disorders, such as mood disorders, is common^34,39.

4.2. Classifications

There are several universal criteria for determining whether a person’s behavior can be diagnosed as an anxiety disorder. These criteria are included in the two most important mental (or psychopathological) disorder classifications:

1. DSM-IV- TR (American Psychiatric Association, APA).
2. CIE-10 (World Health Organization, WHO).

The DSM-IV-TR lists twelve anxiety disorders, and in the CIE-10, neurotic disorders (anxiety) are grouped with stress-related and somatomorphic disorders (table 5)^40,41.

Table 5. Anxiety disorder classifications according to the DSM-IV-TR and the CIE-10: equivalence

The following table presents the classification of these anxiety disorders according to the DSM-IV-TR-AP manual³⁰. This manual was prepared between Primary Care and Psychiatry in order to diagnose mental disorders in PC, and all of the codes included in it are taken from the DSM-IV-TR. Table 6 includes the anxiety disorders according to the DSM-IV-TR-AP, along with the official codes of the CIE-9-MC and the CIE-10 codes.

Table 6. Anxiety disorder classification according to the DSM-IV-TR-AP

And lastly, the International Primary Care Classification "CIAP-2" from the WONCA⁴². This classification is based on three-digit alphanumeric codes, which can be expanded if necessary. The first is a letter that represents the organic system or apparatus, and covers the 17 chapters of this classification. Anxiety-related aspects would be represented under the “P-psychological problems” heading of the abbreviated CIAP-2 codes. The second and third digits are numbers, called components, which are related specifically or non-specifically with: signs or symptoms; administrative, diagnostic, preventive, or therapeutic procedures; complementary test results; referrals, tracking, or other visit motives, or illnesses and health problems. The CIAP-2 codes that correspond to anxiety are shown in the table below as components. The table also specifies the equivalence with the CIE-10 codes:

Table 7. Abbreviated CIAP-2 codes for anxiety