Psychiatric genetics
Encyclopedia
Psychiatric genetics, a subfield of behavioral neurogenetics
, studies the role of genetics in psychological conditions such as alcoholism
, schizophrenia
, bipolar disorder
, and autism
. The basic principle behind psychiatric genetics is that genetic polymorphisms
, as indicated by linkage to e.g. a single nucleotide polymorphism
(SNP), are part of the etiology
of psychiatric disorders
.
The goal of psychiatric genetics is to better understand the etiology of psychiatric disorders, to use that knowledge to improve treatment methods, and possibly also to develop personalized treatments based on genetic profiles (see pharmacogenomics
). In other words, the goal is to transform parts of psychiatry into a neuroscience
-based discipline.
Linkage
, association
, and microarray
studies generate raw material for findings in psychiatric genetics.
Copy number variants have also been associated with psychiatric conditions.
Most psychiatric disorders are highly heritable
; the estimated heritability for bipolar disorder
, schizophrenia
, and autism
(80% or higher) is much higher than that of diseases like breast cancer
and Parkinson disease. However, linkage analysis and genome-wide association studies have found few reproducible risk factors
.
Several genetic risk factors have been found with the endophenotype
s of psychiatric disorders, rather than with the diagnoses themselves. That is, the risk factors are associated with particular symptoms, not with the overall diagnosis.
Behavioural genetics
Quantitative human behavioural genetics is a specialisation in the biological field of behaviour genetics that studies the role of genetics in human behaviour employing quantitative-genetic methods. The field is an overlap of quantitative genetics and psychology...
, studies the role of genetics in psychological conditions such as alcoholism
Alcoholism
Alcoholism is a broad term for problems with alcohol, and is generally used to mean compulsive and uncontrolled consumption of alcoholic beverages, usually to the detriment of the drinker's health, personal relationships, and social standing...
, schizophrenia
Schizophrenia
Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...
, bipolar disorder
Bipolar disorder
Bipolar disorder or bipolar affective disorder, historically known as manic–depressive disorder, is a psychiatric diagnosis that describes a category of mood disorders defined by the presence of one or more episodes of abnormally elevated energy levels, cognition, and mood with or without one or...
, and autism
Autism
Autism is a disorder of neural development characterized by impaired social interaction and communication, and by restricted and repetitive behavior. These signs all begin before a child is three years old. Autism affects information processing in the brain by altering how nerve cells and their...
. The basic principle behind psychiatric genetics is that genetic polymorphisms
Polymorphism (biology)
Polymorphism in biology occurs when two or more clearly different phenotypes exist in the same population of a species — in other words, the occurrence of more than one form or morph...
, as indicated by linkage to e.g. a single nucleotide polymorphism
Single nucleotide polymorphism
A single-nucleotide polymorphism is a DNA sequence variation occurring when a single nucleotide — A, T, C or G — in the genome differs between members of a biological species or paired chromosomes in an individual...
(SNP), are part of the etiology
Etiology
Etiology is the study of causation, or origination. The word is derived from the Greek , aitiologia, "giving a reason for" ....
of psychiatric disorders
Mental illness
A mental disorder or mental illness is a psychological or behavioral pattern generally associated with subjective distress or disability that occurs in an individual, and which is not a part of normal development or culture. Such a disorder may consist of a combination of affective, behavioural,...
.
The goal of psychiatric genetics is to better understand the etiology of psychiatric disorders, to use that knowledge to improve treatment methods, and possibly also to develop personalized treatments based on genetic profiles (see pharmacogenomics
Pharmacogenomics
Pharmacogenomics is the branch of pharmacology which deals with the influence of genetic variation on drug response in patients by correlating gene expression or single-nucleotide polymorphisms with a drug's efficacy or toxicity...
). In other words, the goal is to transform parts of psychiatry into a neuroscience
Neuroscience
Neuroscience is the scientific study of the nervous system. Traditionally, neuroscience has been seen as a branch of biology. However, it is currently an interdisciplinary science that collaborates with other fields such as chemistry, computer science, engineering, linguistics, mathematics,...
-based discipline.
Linkage
Genetic linkage
Genetic linkage is the tendency of certain loci or alleles to be inherited together. Genetic loci that are physically close to one another on the same chromosome tend to stay together during meiosis, and are thus genetically linked.-Background:...
, association
Genetic association
Genetic association is the occurrence, more often than can be readily explained by chance, of two or more traits in a population of individuals, of which at least one trait is known to be genetic....
, and microarray
DNA microarray
A DNA microarray is a collection of microscopic DNA spots attached to a solid surface. Scientists use DNA microarrays to measure the expression levels of large numbers of genes simultaneously or to genotype multiple regions of a genome...
studies generate raw material for findings in psychiatric genetics.
Copy number variants have also been associated with psychiatric conditions.
Most psychiatric disorders are highly heritable
Heredity
Heredity is the passing of traits to offspring . This is the process by which an offspring cell or organism acquires or becomes predisposed to the characteristics of its parent cell or organism. Through heredity, variations exhibited by individuals can accumulate and cause some species to evolve...
; the estimated heritability for bipolar disorder
Bipolar disorder
Bipolar disorder or bipolar affective disorder, historically known as manic–depressive disorder, is a psychiatric diagnosis that describes a category of mood disorders defined by the presence of one or more episodes of abnormally elevated energy levels, cognition, and mood with or without one or...
, schizophrenia
Schizophrenia
Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...
, and autism
Autism
Autism is a disorder of neural development characterized by impaired social interaction and communication, and by restricted and repetitive behavior. These signs all begin before a child is three years old. Autism affects information processing in the brain by altering how nerve cells and their...
(80% or higher) is much higher than that of diseases like breast cancer
Breast cancer
Breast cancer is cancer originating from breast tissue, most commonly from the inner lining of milk ducts or the lobules that supply the ducts with milk. Cancers originating from ducts are known as ductal carcinomas; those originating from lobules are known as lobular carcinomas...
and Parkinson disease. However, linkage analysis and genome-wide association studies have found few reproducible risk factors
Risk factors
A risk factor is a concept in finance theory such as the CAPM, APT and other theories that use pricing kernels. In these models, the rate of return of an asset is a random variable whose realization in any time period is a linear combination of other random variables plus a disturbance term or...
.
Several genetic risk factors have been found with the endophenotype
Endophenotype
Endophenotype is a psychiatric concept and a special kind of biomarker. The purpose of the concept is to divide behavioral symptoms into more stable phenotypes with a clear genetic connection...
s of psychiatric disorders, rather than with the diagnoses themselves. That is, the risk factors are associated with particular symptoms, not with the overall diagnosis.
See also
- International Behavioural and Neural Genetics SocietyInternational Behavioural and Neural Genetics SocietyThe International Behavioural and Neural Genetics Society was founded in 1996. The goal of IBANGS is "to promote the field of neurobehavioural genetics".- Mission :...
(IBANGS) - Gene-environment correlationGene-environment correlationGene-environment correlation is said to occur when exposure to environmental conditions depends on an individual's genotype.-Definition:...
- Genetic predispositionGenetic predispositionA genetic predisposition is a genetic affectation which influences the phenotype of an individual organism within a species or population but by definition that phenotype can also be modified by the environmental conditions. In the rest of the population, conditions cannot have that effect...
- Psychiatric Genetics (journal)Psychiatric Genetics (journal)Psychiatric Genetics is a scientific journal published by Lippincott Williams & Wilkins within the field of psychiatric genetics. It is published 6 times a year and is abstracted and indexed in Medline/PubMed and the Science Citation Index....
- Genes, Brain and BehaviorGenes, Brain and BehaviorAccording to the Journal Citation Reports, its 2009 impact factor is 4.061, ranking Genes, Brain and Behavior 63rd out of 237 listed journals in the category "Neurosciences" and 6th out of 48 listed journals in the category "Behavioral Sciences"....
(journal)