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

Clinical profile major depressive disorder:

It is an episodic disorder because symptoms tend to be present for a period of time and then clear. People with persistent depressive disorder are chronically depressed. Clinical profile:

The symptoms do not clear for more than 2 months at a time. Bipolar disorders are not present. Women are more likely than men to develop

Obsessive-compulsive and related disorders are defined by repetitive thoughts and behaviours that are so extreme that they interfere with everyday life. Obsessions are repetitive thoughts and urges. Compulsions are repetitive behaviours or mental acts. Compulsions are often not seen as pleasurable by the patient. OCD begins before age 10 or in late adolescence/early adulthood.

Clinical profile Obsessive-compulsive disorder:

People with body dysmorphic disorder (BDD) are preoccupied with one or more imagined or exaggerated defects in their appearance. People with BDD find it very hard to stop thinking about their concerns. BDD is associated with suicide ideation. It typically begins in adolescence. If weight and body shape are the only concerns about appearance, it might fit the profile of an eating disorder better. Clinical profile body dysmorphic disorder:

Psychosis is a disruption in the experience of reality or disruption of reality testing. Hallucinations are perception-like experiences which occur without an external stimulus and the most common hallucinations are auditory hallucinations. It is not uncommon, as children tend to experience audio-visual hallucinations but this tends to stop at the age of 12 or 13. Delusions are fixed beliefs that are not amenable to change in light of conflicting evidence. They are deemed bizarre if they are implausible, not understandable from same-culture peers and do not derive from ordinary life. There are several types of delusions:

1. Persecutory (most common)
   The idea that a person is being persecuted
2. Referential (most common)
   The idea that there is personal significance in trivial activities of others (e.g., seeing messages)
3. Somatic
   The idea that one’s bodily function or appearance is grossly abnormal
4. Grandiose delusions
   The idea that the person is of exaggerated importance
5. Erotomanic
   The idea that another person (e.g: celebrity) is in love with the person
6. Nihilistic
   The idea that there is impending doom
7. Thought insertion
   The idea that thoughts are being inserted
8. Thought broadcasting
   The idea that thoughts are being broadcast

Schizophrenia includes positive, negative and disorganized symptoms. Positive symptoms consist of symptoms that make it difficult for a person to tell what is real and what is not. Negative symptoms consist of behavioural deficits in motivation, pleasure, social closeness and emotion expression. Disorganized symptoms refer to the lack of ability to organize behaviour and conform to community standards. Catatonic behaviour is extremely disorganized behaviour. There are several negative symptoms:

1. Avolition (apathy) (most common)
   Reduced self-motivated goal-oriented behaviour
2. A-sociality
   Reduced interest in social activities
3. Anhedonia
   Reduced experience of pleasure
4. Alogia
   Reduced speech production
5. Blunted affect (most common)
   Lack of outward expression of emotion without regards to the inner experience of emotion

Other symptoms include jumping to conclusions (1), disrupted self-experience (2), neurocognitive difficulties (3) and anosognosia (4): reduced insight into the illness. The severity of symptoms can be assessed using the Positive and Negative Syndrome Scale (PANSS) and using the beads task. Neurocognitive deficits can be measured by measuring working memory.

There is a strong genetic component in schizophrenia. There are several risk factors for developing a psychosis: being a migrant (1), urbanization (2), social exclusion (3) and trauma (4). A psychosis can be traumatic. A sense of social exclusion can play an important role in developing psychosis.

The social defeat hypothesis states that social exclusion increases the risk of psychosis. The dopamine hypothesis states that schizophrenia is related to excess activity of dopamine. The dopamine neurons in the prefrontal cortex may be underactive, which leads to overactivity of dopamine in the rest of the brain.

The cognitive model of auditory hallucinations states that an intrusive thought occurs, which is misattributed to an external source.

Eating disorders are not very stable. There is a lot of movement between the disorders. People with anorexia nervosa choose a thin figure as their ideal and overestimate their own body size, but are fairly accurate at reporting their weight. Maintaining thinness is strongly linked to self-esteem in anorexia nervosa.

There are several biological consequences of anorexia nervosa: falling of blood pressure (1), slowing of heart rate (2), decline of bone mass (3), kidney and gastrointestinal problems (4), drying of the skin (5), brittle nails (6), change in hormone levels (7), alteration of electrolytes (e.g., potassium) (8), tiredness (9) and lanugo (10).

Lanugo is a fine, soft hair that develops on the body in people with anorexia nervosa. 50%-70% of the people with anorexia nervosa recover, but it takes ±6-7 years to recover. Severity ratings in anorexia nervosa are based on BMI.

Bulimia nervosa and binge-eating disorder include binge eating. A binge is most likely to occur after a negative social interaction. Maintaining normal weight is strongly linked to self-esteem in bulimia nervosa. Most people with bulimia nervosa were slightly overweight before the onset of the disorder and binge eating started during an episode of dieting.

There are several biological consequences of bulimia nervosa: potassium depletion (1), diarrhoea (2), irregularities in heartbeat (3), menstrual problems (4), ragged teeth (5), swollen salivary glands (6) and tearing of tissue in the stomach and throat (7). Close to 75% of the people with bulimia nervosa recover. There are several biological consequences of binge eating disorder, with most of them being a consequence of obesity: sleep problems (1), anxiety (2), depression (3), irritable bowel syndrome (4) and early onset of menstruation (5).

Eating disorders are highly heritable. The hypothalamus regulates the level of cortisol in the body and cortisol levels differ in people with anorexia nervosa, but these hormonal differences are most likely to occur because of self-starvation. Self-starvation and excessive exercise may also increase endogenous opioids, substances produced by the body that reduce pain sensations, enhance mood and suppress appetite. Endogenous opioids may positively reinforce the behaviour that maintains the disorder.

Serotonin promotes satiety and severe food intake restrictions could interfere with the serotonin system. Dopamine is linked to the pleasurable aspects of food that compel an animal to go after food. Restrained eaters may be more sensitive to food cues. People with anorexia nervosa and bulimia nervosa had a greater expression of the dopamine transporter gene DAT. Expression of DAT influences the release of a protein that regulates the reuptake of dopamine back into the synapse.

Perfectionism and a sense of personal inadequacy may lead a person to become especially concerned with appearance. Western culture emphasizes and reinforces the desirability of being thin more for women than for men. The objectification of women’s bodies exaggerates this effect. Body shame has a negative influence on eating disorders, as well as criticism

Whether the behaviour is seen as problematic depends on culture. Externalizing disorders are characterised by more outward-directed behaviours. Internalizing disorders are characterised by more inward-focused experiences and behaviours.

There are three sub-types of ADHD:

1. Predominantly inattentive
2. Predominantly hyperactive-impulsive
3. Combined

People with ADHD tend to have problems getting along with peers and establishing friendships. They show poor social skills (1), aggressive behaviour (2) and overestimate their social skills (3). The combined type is the most likely to develop conduct problems.

The heritability of ADHD is ±70-80%. They have smaller dopaminergic areas in the brain, there are differences in brain structure, connectivity and function and they exhibit less activation in frontal areas. Frontal areas are important for the inhibition of behaviour. Low birth-weight (1), maternal smoking (2), interaction with family (3) and family characteristics (parental psychopathology) (4) are factors that can impact the development and can maintain or exacerbate the symptoms of ADHD. Food additives may help maintain or exacerbate the symptoms.

There are two paths of conduct disorder:

1. Life-course persistent conduct disorder (age 3 – life)
   Problematic behaviour from age three, which lasts throughout life.
2. Adolescence-limited conduct disorder (adolescence)
   A relatively normal childhood, problematic adolescence and normal adulthood.

The adolescence-limited conduct disorder could result from a difference in physical maturation and the opportunity to assume adult responsibilities. Deficits in brain regions that support emotion (empathy) (1), deficiency in moral awareness (2), social information processing deficits (3), autonomic nervous system abnormalities (4) and peer rejection (5) are risk factors for conduct disorder. Ambiguous cues are often misinterpreted as evidence of hostile intent. Neighbourhood and family factors play a role in whether children associate with deviant peers.

The prevalence of depression in school-age children under 13 is ±2-3% and rises to ±6-16% in adolescence. Genetics (1), significant interpersonal stressful live events (2)¸ rejection by parents, cognitive distortions and a negative attributional style are risk factors for depression in children. The attributional style becomes stable by adolescence. The benefits of CBT may not last long for children and the side-effects of medication may be extreme for children.

Separation anxiety disorder is characterized by constant worry that some harm will befall their parents or themselves when they are away from their parents. For children, in order to be diagnosed with anxiety disorders, the fear does not need to be considered irrational as children are unable to make this judgement.

The heritability of anxiety disorders is ±29-50%. Parental control (1), insecure attachment style in infancy (2), overprotectiveness of parents (3), emotion regulation problems (4) and high levels of behavioural inhibition (5) are risk factors for the development of anxiety disorders in children.

A specific learning disorder is a condition in which a person shows a problem in a specific area of academic, speech, language

Personality refers to a combination of unique traits expressed in thoughts, behaviours, feelings and interpersonal functioning. It is relatively stable over time and over situations. Personality disorders are pervasive, persistent and pathological. It can be assessed using semi-structured interviews (1), file research (2), using observations (3) and using heteroanamnesis, asking someone close to the person. They are dimensional in nature and the prevalence of a personality disorder is ±10%. The prevalence of personality disorders in prisons is ±60-70%. There is high comorbidity between the personality clusters.

Psychopathic people have no shame, poverty of emotions and manipulate others for personal gain. They seem unable to learn from experience, are insensitive to threats and immune to anxiety that keeps most people from breaking the law. Boldness (1), meanness (2) and impulsivity (3) underly psychopathy.

Problems with dopamine systems are involved in cognitive problems. Problems with serotonin systems are involved in anger and impulse control. Problems with MAO systems are involved with aggression. A dysfunctional amygdala leads to either hyper-emotionality or hypo-emotionality. A lack of frontal cortical control leads to impulses.