Aetiology of Psychiatric Disorders Prof Elham aljammas 16/10/2016

In Psychiatry, the study of causation is complicated by two problems: Causes are often remote in time from the effects that they produce e.g. childhood experience  adult anxiety disorders. 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 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 Precipitating factors Perpetuating factors Recovery

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.

Schizophrenia in identical twins MRI shows enlarged ventricles in twin with schizophrenia. Source: Daniel Weinberger, MD, NIMH Brain Disorders Branch

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. 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.

We see with our brains, not with our eyes We see with our brains, not with our eyes. Our eyes send information to our brains and our brains interpret the images.

Normal Psychotic A person whose perceptions are normal will see a flower and recognize it as a flower. A person experiencing psychosis will often be unable to interpret what his or her eyes see.

Interventions for Mental Illness No One Intervention Is Sufficient We Have to Approach from All Directions Copyright © 2006 Cynthia Bisbee, Ph.D.