Aetiology of Psychiatric Disorders Dr. Fatima Alhaidar Professor & Consultant Child & Adolescent Psychiatrist College of Medicine, KSU.

Vague but important to: 1. Diagnose and understand. 2. Allow early intervention. 3. Optimize treatment.

In Psychiatry, the study of causation is complicated by two problems: 1. Causes are often remote in time from the effects that they produce e.g. childhood experience  adult anxiety disorders. 2. a) A single cause may lead to several effects e.g. deprivation of parental affection  antisocial behavior, suicide, depression… b) A single effect may arise from several causes e.g. M.R. Depression.

Classification of Causes: 1- According to nature: a) Biological b) Psychological c) Social

2- According to the effect: a. Predisposing factors b. Precipitating factors c. Perpetuating (maintaining) factors

A- Predisposing factors: - Operating from early life, that determine a person’s vulnerability to causes acting close to the time of illness. -Constitution is often used to describe the mental and physical make up of a person at any point in his life  Personality is always an essential element that help to explain why the patient responds to certain stressful events and he reacts in a particular way. e.g. - Genetic endowment - Environment in utero - Trauma at birth - Social & psychological factors in infancy & early childhood.

B- Precipitating factors: Events that occur shortly before the onset of a disorder and appear to have induced it. e.g. -Physical disease -Drug -Loss of job -Changing residency

C- Perpetuating factors: These factors prolong the course of a disorder after it has been provoked. e.g. - Intrensic to the disorder (avoidance in phobic disorders) -Social circumstances (marital discords, over protecting parents).

Predisposing factors Constitution Illness Recovery Precipitating factors Perpetuating factors

Approaches to Etiology: 1. Genetics: -Family risk studies -Twin studies -Adoption studies -Genetic causes have been studies mainly in moderate to severe mood disorders and schizophrenia.

2. Biochemical studies: - Can be directed either to the cause of the disease or to the mechanism by which it produces its effect. -Most studies have focused on the monoamine neurotransmitters. -5 Hydroxy tryptamine. -Noradrenaline -Dopamine

3. 3. Endocrinology: Hormonal changes can have profound effects or mood and behavior.

4. Neuropathology: - Attempt to answer the question as to whether a structural change in the brain (localized or diffuse) accompanies a particular kind of mental disorder. -There is an obvious application to the etiology of dementia and other psychiatric disorders associated with organic lesions.

5. Psychological theories of etiology: a) Psychoanalysis - Provides a comprehensive range of explanation for clinical phenomena. -The central feature is the concept of unconscious mind which characterized by: a – divorce from reality b – being dynamic c – being in conflict with the conscious mind. -It is important in the etiology of neurotic disorders. -Neurosis originate from failure to pass normally through 3 stages of development oral  anal  genital. -Anxiety is the central symptom of all neurosis. -Defense mechanisms (such as rationalization and projection) are used to reduce anxiety.

b) Learning theories: Experiences in childhood and later life give rise to neurosis.

c) Cognitive theories: Symptoms and behavior are produced and maintained by maladaptive ways of thinking.

6. Social Science: Many of the concepts used by sociologists are relevant to psychiatry. e.g. (1) Life events  Migration, unhappy marriage, problems of work. (2) Family factors  lack of social support, criticism, and over protection within the family.

Example: - A 33 year old woman. -Mother of 5 children. - Presents with low mood and diminished interest in life activities. - Divorced 8 months ago and return back to live with her family. -Her father faces financial difficulties. -Her grand father has history of major depression. -Evil eye by a relative.