Causes for abnormal behavior
• Abnormal behaviour, also known as psychopathology or mental disorder, refers
to patterns of thoughts, feelings, or actions that deviate significantly from the
norm and cause distress, impair functioning, or pose a risk to oneself or others.
• Multiple factors influence abnormal behaviour and mental disorders. The major
factors involved are biological, psychological, social, and socio-cultural. It is
called integrative because no one factor in isolation impacts the behaviour, but
multiple factors interact to influence abnormal behaviour.
BIOLOGICAL CAUSAL FACTORS
• Biological factors, also known as biological influences or determinants, refer to the
physiological and genetic characteristics of an individual that can influence their
behavior, cognitive processes, and overall mental and physical health.
• These factors are rooted in the biology of the body and brain and can have a significant
impact on various aspects of human functioning.
• Four categories of biological factors that seem particularly relevant to the of
maladaptive behaviour:
o Neurotransmitter and Hormonal imbalances in the brain,
o Genetics,
o Constitutional liabilities
o Brain structure
o Physical deprivation or disruption
NEUROTRANSMITTER IMBALANCE
• The 100 billion neurons in the central nervous system (CNS) communicate by chemical
messengers called neurotransmitters. When these neurotransmitters become
imbalanced they give rise to many psychological problems.
• Neurotransmitters (e.g., serotonin, dopamine, nor epinephrine, GABA) are released
into the synaptic cleft. They regulate level of mood, anxiety, and cognitive functioning.
• Factors affecting neurotransmitter imbalance include:
o Excessive production and release of the neurotransmitter substance into
the synapses, causing an excess in levels of that neurotransmitter.
o Dysfunctions in the normal processes by which neurotransmitters are
deactivated after they are released into the synapse.
o Problems in the receptors in the postsynaptic neuron, which may either
be abnormally sensitive or insensitive.
• Different disorders are thought to occur from different patterns of neurotransmitter
imbalances. Different types of drugs that are used to treat various disorders are believed
to work by correcting these imbalances.
• For example, the antidepressant drug Prozac slows down the re-uptake process of the
neurotransmitter serotonin. Dopamine has been implicated in schizophrenia and GABA
has been strongly implicated in anxiety.
Hormonal Imbalance
, • Hormones are chemicals messengers secreted by the endocrine glands (e.g., pituitary).
• They play a role in the functioning of the nervous system and in the regulation of
behaviour (e.g., during adolescence, changes in the hypo thalamic pituitary-adrenal
axis are involved in the increase in cortisol, a stress-related hormone). Malfunction of
this system has been said to be responsible for various forms of psychopathology.
• Hormonal influences are also responsible for the differences in behaviour between men
and women.
Genetics
• Genes play an important role in determining risks for both psychotic and non psychotic
disorders.
• For example, the lifetime risk of schizophrenia is 1%, but for the offspring of an
affected person it becomes 10% and in bipolar disorder is 20%.Hormonal influences
are also responsible for the differences in behaviour between men and women.
• For most major mental disorders (e.g., schizophrenia, the major mood disorders,
anxiety disorders, alcohol-use disorders), twin and/or adoption studies have
demonstrated significant genetic effects.
Heritability:
• Heritability refers to the proportion of individual differences in a trait or behavior that
can be attributed to genetic factors within a specific population.
• For many mental health conditions, including schizophrenia, bipolar disorder, major
depressive disorder, and anxiety disorders, there is evidence of heritability.
• This means that individuals with a family history of these disorders may have a higher
risk of developing them compared to the general population.
Constitutional Liabilities
• The term ‘constitutional’ is used to describe any characteristic that is either innate or
acquired early in life often at prenatal stage and in such strength that it is functionally
similar to a genetic characteristic.
• Physical handicaps and temperament are some of the traits included in this category.
• Embryonic abnormalities or environmental conditions operating before or after birth
may result in physical defects.
• The most common birth difficulty associated with learning disabilities and behavioural
and emotional disorders is low birth weight.
• Prenatal conditions that can lead to premature birth and low birth weights include
nutritional deficiencies, disease, and exposure to radiation, drugs, severe emotional
stress or mother’s excessive use of alcohol or tobacco.
TEMPERAMENT
• The temperament of an infant or young child has profound effects on a variety of
important developmental processes
• For example, a child with fearful temperament would become conditioned to ‘fear
situations’ in which fear is provoked. Later the child may learn to avoid entering these
• Abnormal behaviour, also known as psychopathology or mental disorder, refers
to patterns of thoughts, feelings, or actions that deviate significantly from the
norm and cause distress, impair functioning, or pose a risk to oneself or others.
• Multiple factors influence abnormal behaviour and mental disorders. The major
factors involved are biological, psychological, social, and socio-cultural. It is
called integrative because no one factor in isolation impacts the behaviour, but
multiple factors interact to influence abnormal behaviour.
BIOLOGICAL CAUSAL FACTORS
• Biological factors, also known as biological influences or determinants, refer to the
physiological and genetic characteristics of an individual that can influence their
behavior, cognitive processes, and overall mental and physical health.
• These factors are rooted in the biology of the body and brain and can have a significant
impact on various aspects of human functioning.
• Four categories of biological factors that seem particularly relevant to the of
maladaptive behaviour:
o Neurotransmitter and Hormonal imbalances in the brain,
o Genetics,
o Constitutional liabilities
o Brain structure
o Physical deprivation or disruption
NEUROTRANSMITTER IMBALANCE
• The 100 billion neurons in the central nervous system (CNS) communicate by chemical
messengers called neurotransmitters. When these neurotransmitters become
imbalanced they give rise to many psychological problems.
• Neurotransmitters (e.g., serotonin, dopamine, nor epinephrine, GABA) are released
into the synaptic cleft. They regulate level of mood, anxiety, and cognitive functioning.
• Factors affecting neurotransmitter imbalance include:
o Excessive production and release of the neurotransmitter substance into
the synapses, causing an excess in levels of that neurotransmitter.
o Dysfunctions in the normal processes by which neurotransmitters are
deactivated after they are released into the synapse.
o Problems in the receptors in the postsynaptic neuron, which may either
be abnormally sensitive or insensitive.
• Different disorders are thought to occur from different patterns of neurotransmitter
imbalances. Different types of drugs that are used to treat various disorders are believed
to work by correcting these imbalances.
• For example, the antidepressant drug Prozac slows down the re-uptake process of the
neurotransmitter serotonin. Dopamine has been implicated in schizophrenia and GABA
has been strongly implicated in anxiety.
Hormonal Imbalance
, • Hormones are chemicals messengers secreted by the endocrine glands (e.g., pituitary).
• They play a role in the functioning of the nervous system and in the regulation of
behaviour (e.g., during adolescence, changes in the hypo thalamic pituitary-adrenal
axis are involved in the increase in cortisol, a stress-related hormone). Malfunction of
this system has been said to be responsible for various forms of psychopathology.
• Hormonal influences are also responsible for the differences in behaviour between men
and women.
Genetics
• Genes play an important role in determining risks for both psychotic and non psychotic
disorders.
• For example, the lifetime risk of schizophrenia is 1%, but for the offspring of an
affected person it becomes 10% and in bipolar disorder is 20%.Hormonal influences
are also responsible for the differences in behaviour between men and women.
• For most major mental disorders (e.g., schizophrenia, the major mood disorders,
anxiety disorders, alcohol-use disorders), twin and/or adoption studies have
demonstrated significant genetic effects.
Heritability:
• Heritability refers to the proportion of individual differences in a trait or behavior that
can be attributed to genetic factors within a specific population.
• For many mental health conditions, including schizophrenia, bipolar disorder, major
depressive disorder, and anxiety disorders, there is evidence of heritability.
• This means that individuals with a family history of these disorders may have a higher
risk of developing them compared to the general population.
Constitutional Liabilities
• The term ‘constitutional’ is used to describe any characteristic that is either innate or
acquired early in life often at prenatal stage and in such strength that it is functionally
similar to a genetic characteristic.
• Physical handicaps and temperament are some of the traits included in this category.
• Embryonic abnormalities or environmental conditions operating before or after birth
may result in physical defects.
• The most common birth difficulty associated with learning disabilities and behavioural
and emotional disorders is low birth weight.
• Prenatal conditions that can lead to premature birth and low birth weights include
nutritional deficiencies, disease, and exposure to radiation, drugs, severe emotional
stress or mother’s excessive use of alcohol or tobacco.
TEMPERAMENT
• The temperament of an infant or young child has profound effects on a variety of
important developmental processes
• For example, a child with fearful temperament would become conditioned to ‘fear
situations’ in which fear is provoked. Later the child may learn to avoid entering these
