A psychological disorder is difficult to define. There is no consensus on the definition of a psychological disorder. A psychological disorder definition should include the following four characteristics:

1. Personal distress
   The disorder must result in personal distress.
2. Disability
   The disorder must result in an impairment in some important area of life.
3. Violation of social norms
   The disorder must result in behaviour that violates social norms.
4. Dysfunction
   The disorder must result (or be the result of) in an internal mechanism not working properly.

Demonology refers to the doctrine that an evil being or spirit can dwell within a person and control his or her mind and body. People used to be treated very inhumane in asylums. They were chained and tortured. After this moral treatment started, humane treatment. This was abandoned later in 1800.

After the connection between syphilis and paralysis, biological bases were seen as the cause of psychological disorders. After the observation of mass hysteria, a more psychological approach was being taken. The cathartic method refers to treating psychological disorders by reliving an earlier emotional trauma and releasing emotional tension by expressing previously forgotten thoughts about the events. Transference refers to the person’s responses to his or her analyst that seem to reflect attitudes and ways of behaving toward important people in the person’s past. The collective unconscious is part of the unconsciousness that is common to all human beings and consists of archetypes, basic categories for conceptualizing the world.

Freud still has an influence on modern-day psychology in the following three assumptions: childhood experiences help shape adult personality (1), there are unconscious influences on behaviour (2) and the causes and purposes of human behaviour are not always obvious (3). Appraisals are part of cognitive therapy.

A correct diagnosis will allow the clinician to describe base rates, causes and treatment. Reliability and validity are the cornerstones of any diagnostic or assessment procedure. Reliability refers to the consistency of measurement. Validity refers to measuring what you want to measure. Alternate form reliability refers to the extent to which scores on two forms of the test are consistent. Criterion validity is evaluated by determining whether a measure is associated expectedly with some other measure. If both variables are being measured at the same time, it is concurrent validity.

The diagnostic and statistical manual of mental disorders (DSM) is the diagnostic system used by many mental health professionals. Specific diagnostic criteria (1) and extensively described characteristics of diagnosis (2) were added to the DSM-III and have been retained ever since.

There are some major changes of the DSM into the DSM-5:

1. Removal of the multiaxial system
2. Organizing diagnoses by causes
   There are no proper tests to organize diagnoses around aetiology, so the diagnosis is based around symptoms. The chapters in DSM-5 are organized to reflect patterns of comorbidity and shared aetiology.
3. Enhanced sensitivity to the developmental nature of psychopathology
   Across diagnoses, more detail is provided about the expression of symptoms in younger populations.
4. New diagnoses
   New diagnoses were added to the DSM-5.
5. Combining diagnoses
6. Ethnic and cultural considerations in diagnosis
   There are many different cultural influences on the risk factors for psychological disorders, the types of symptoms experienced, the willingness to seek help and the treatments available.

There are some criticisms of the DSM:

1. Too many diagnoses
   A side effect of the huge number of diagnostic categories is comorbidity. Different diagnoses do not seem to be distinct in their aetiology or treatment and this can lead to too many diagnoses.
2. Categorical classification versus dimensional classification
   Categorical classification refers to putting people in categories (e.g: disorder “yes” or “no”). It could be useful to use dimensional classification, describing the degree to which a disorder is present. Advantages of categorical classification are being more certain on when to offer treatment.
3. Reliability of the DSM
   The reliability of the DSM has to be good for the DSM to be useful. The DSM is not always reliable.
4. Validity of the DSM
   The DSM is not always very valid.

Diagnosing someone can have the disadvantages of changing a person’s ability to function and stigmatize a person. Diagnosis can lead us to focus on the disorder and ignore important differences among people.

There are several methods in which psychological assessment can be obtained.

Mental health professionals can use formal and structures as well as informal and fewer structures clinical interviews for psychological assessment. In a clinical interview, the interviewer pays attention to how the respondent answers questions. Trust is imperative for psychological treatment. A structured interview can be

Anxiety disorders include fear and anxiety. Anxiety refers to apprehension over an anticipated problem. Fear is a reaction to immediate danger. Fear happens at the moment and anxiety involves a future threat. In all anxiety disorders, except for a panic disorder, the symptoms must persist for at least 6 months. The symptoms must persist for at least one month for a panic disorder.

Clinical profile-specific phobia (e.g: snakes, spiders, heights):

The object of phobia may also elicit intense disgust. Specific phobias are highly comorbid.

Clinical profile social anxiety disorder:

The social anxiety disorder can be about a specific social situation (e.g: speaking in public) and doesn’t necessarily include all social situations. Severe social anxiety is highly comorbid with depression and alcohol abuse. People with social anxiety can demonstrate aggressive and hostile behaviour in the face of potential social rejection.

Clinical profile panic disorder:

Panic attacks are unrelated to specific situations.

Clinical profile panic attack:

Dissociation refers to some aspect of emotion, memory or experience being inaccessible consciously. Depersonalization/derealization involves a form of dissociation involving detachment. The person feels removed from the sense of self and surroundings. The lifetime prevalence of depersonalization/derealization disorder is about 2.5%. The lifetime prevalence of dissociative amnesia is about 7.5%. The lifetime prevalence of dissociative identity disorder is about 1%-3%.

Clinical profile depersonalization/derealization disorder:

This disorder involves no disturbances of memory. It usually begins in adolescence and is usually triggered by stress. It is very comorbid with personality disorders, depression and anxiety disorders. Depersonalization refers to experiences of detachment from one’s mental processes or body (e.g: as in a dream). Derealization refers to experiences of unreality of surroundings.

Clinical profile dissociative amnesia:

The amnesia usually disappears as suddenly as it began, with complete recovery and only a small chance of recurrence. Procedural memory remains intact during episodes of amnesia. Alcohol and medication can cause blackouts and potentially explain the amnesia. Dissociative amnesia and fugue are rare, even among people who have experienced intense trauma. People experiencing stress tend to focus on the central features of the threatening situation and stop paying attention to peripheral features. People tend to remember emotionally relevant information more than neutral information surrounding an event. It is possible that extremely high levels of stress hormones could interfere with memory formation.

Clinical profile dissociative identity disorder: