Dysfunctional or abnormal behavior is any behavior judged to be disturbing, atypical, maladaptive or unjustifiable. It can be irrational, unpredictable and unconventional. The person can feel distress and discomfort from their behaviors. It is different from insanity which is a legal defense; insanity means that the individual could understanding the difference between right and wrong, and is unable to control their actions.

There are four perspectives on psychopathology or the study of dysfunctional behavior:

medical (or biological) model: dysfunctional behavior is the result of an organic cause; Philippe Pinel and Emil Kraepelin created two of the first medical classification systems for psychological disorders
behavioral model: abnormal behavior is the result of maladaptive learning (reinforcement)
cognitive model: dysfunctional behavior is the result of irrational or distorted thinking that leads to emotional problems and maladaptive behaviors
psychodynamic model: dysfunctional behavior is the result of internal, unconscious conflicts and motives

Also considered are these perspectives:

humanistic model: abnormal behavior is the result of roadblocks that people encounter on the path to self-actualization whereby people become detached from their true selves and adopt a distorted self-image which leads to emotional problems
ethical model: dysfunctional behavior is the result of a lack of or improper ethical values
sociocultural model: abnormal behavior is the result the stress involved in coping with poverty and other social ills such as unemployment and racism
interactionist (or biopsychosocial) perspective: dysfunctional behavior is the result of a complex interaction between biological processes and genetic predispositions, psychological dynamics and social influences

The first four models are considered to be the four classic perspectives on abnormal behavior.

Psychological disorders have been classified for four main reasons: 1) describe the disorder, 2) predict the course it will take in the future, 3) render appropriate treatment, and 4) prompt further research into its causes and treatments.

In the United States, the DSM-IV (or Diagnostic and Statistical Manual for Mental Disorders, 4th edition) is considered the authoritative source on diagnosing and treating psychological disorders. The DSM-IV distinguishes between neurotic disorders which are affective (or emotional) disorders, and psychotic disorders which are affective and cognitive (or thinking) disorders.

One caution in examining both mental and physical disorders is a phenomenon called medical student syndrome. In this, students who study specific disorders begin to convince themselves that they are suffering from that disorder because they may have one or more general symptoms. Typically this is not the case and worry shifts from the current disorder being studied to the next.

Who determines what's "normal?"

you: individuals constantly assess the normalcy of their behaviors
society: society imposes labels of normal and abnormal behavior
the experts: applying their skill and knowledge in diagnosing and treating psychological disorders

Psychologists have established six criteria in determining the distinction between normal and abnormal behavior: unusualness, social deviance, emotional distress, maladaptive behavior, dangerousness and faulty perceptions or interpretations of reality.

Experts caution that labeling individuals with certain disorders can predispose them to certain self-fulfilling prophesies and cause those around them to perceive them differently based on stereotypical beliefs.


Anxiety disorders involve behaviors the surround overwhelming anxiety and attempts to reduce this anxiety through maladaptive means. Anxiety disorders are among the most common psychological disorders treated by professionals.

The causes of anxiety disorders depend on the model of psychopathology:

biological: disorders are the result of organic causes; neurotransmitter imbalances (anxiety, mood and schizophrenic disorders) and hereditary genetics (schizophrenia) cause the disorder
behavioral: behaviors result from prior reinforcement or conditioning of the maladaptive behavior: rewarding avoidance behaviors can contribute to phobias; relieve from anxiety (negative reinforcement) reinforces OCD
cognitive: anxiety is based on incorrect reasoning, a distortion of real events and unrealistic expectations; misinterpretation of minor changes in bodily sensations promotes anxiety and panic attacks; social phobias may occur because of an obsessive fear of social embarrassment or negative judgments
psychodynamic: anxiety disorders are the result of an unconscious conflict or fear; desire to avoid a previously abrasive experience can generate ritualistic behaviors to reduce anxiety (OCD); phobias may be a result of childhood traumas that have been repressed

Major anxiety disorders include the following:

Generalized anxiety disorder (GAD) is one in which the individual feels continually and unexplainable tense or anxious, worries that bad things might happen, and . This anxiety occurs consistently for at least six months. The individual typically can hide these symptoms but physical symptoms such as insomnia or racing heart) may occur. Freud called this a "free-floating" anxiety because the individual cannot identify what's causing their anxiety; this makes it hard to control it. Lifetime prevalence: 5%.

A panic attack or panic disorder is a condition in which a person suffers a period of intense anxiety. Physical reactions include disorientation, tunnel vision, a feeling a disconnectedness, increased blood pressure, increase heart rate, shortness of breath. Panic attacks typically begin in the mid-20s. Agoraphobia is an intense fear of situations with no escape or help in the event of a panic attack. Lifetime prevalence: 1-4%.

A phobia is an intense irrational fear. The individual usually actively avoids the situation or object of their phobia. Specific phobias involve fear and avoidance of specific objects or situations. Social phobias involve fear and avoidance of social situations or performance situations. Lifetime prevalence: specific phobia 7-11%, social phobia 3-13%.

An obsession is an uncontrollable thought. People may obsess about food, death, sex, etc. A compulsion is an uncontrollable act. These frequently go together in the form of an obsessive-compulsive disorder (OCD). This disorder is characterized by a combination of repetitive thoughts and uncontrollable acts. The two most common types of OCD are chronic hand washers and "checkers," individuals who continually check things in a highly structured way. The onset of this disorder occurs in childhood or adolescence. Research now indicates that there is a biological link to OCD; part of the problem lies in the pathway between the basal ganglia and the frontal lobe. Drug medication that regulates an individual's seritonin level has shown great success in two-thirds of patients. Lifetime prevalence: 2-3%.

Posttraumatic stress disorder (PTSD) involves overwhelming anxiety, flashbacks and troubling recollections of a highly traumatic event. Veterans who have seen heavy combat duty and women who have been raped or assaulted may suffer from this. The individual attempts to avoid situations or objects that might trigger the disorder. Success of treatment depends on whether the individual had any psychological disorders prior to PTSD, their social support group and whether the individual is currently experiencing any other psychological disorders.


Psychosomatic (or psychophysiological) disorders are where there are real physical disorders but no organic or biological cause. These illnesses are brought on by psychological not physiological factors. The two most common types of psychosomatic disorders are migraine headaches and stomach ulcers. These are usually brought on by overwhelming stress.


Somatoform disorders are where there is an apparent physical illness but no organic or biological cause.

The causes of somatoform disorders depend on the model:

biological: there is no biological argument since there are no biological reasons for these disorders
behavior: believe the disorder allows the person to avoid the anxiety-producing situation (see psychodynamic explanation); further reinforcement for the disorder comes in the form of sympathy and support from others for having the physical ailment
cognitive: people are misinterpreting and exaggerating minor bodily sensations as signs of serious illness
psychodynamic: these disorders are an outward sign of an unconscious conflict; in stopping the expressions of the id by the ego, leftover sexual or aggressive energy is converted into a physical symptom; the symptom itself is symbolic of the underlying struggle (e.g. immobilizaton of the arm would prevent the person from carrying out a violent act); the symptom has the secondary gain of preventing the person from having to confront the conflict

Major somatoform disorders include the following:

Somatozation disorder is a disorder where the person has vague physical symptoms and repeatedly seeks medical treatment but no organic cause is found for the illness.
Conversion disorder is a disorder where the person suffers from paralysis, blindness, deafness, seizures. loss of feeling or false pregnancy but with no physiological reason for it. In about 80% of suspected cases, the cause turns out to be medical. This disorder is rare.
Hypochondriasis is a disorder where a person takes insignificant physical symptoms and interprets them as a sign of a serious illness despite a lack of evidence of any organic cause.
Body dysmorphic disorder is a disorder in which a person become preoccupied with his or her imagined physical ugliness that makes normal life impossible.


Dissociative disorders involve a separation (or dissociation) of conscious awareness of the world around the individual and previous thoughts and memories. This can cause a sudden memory loss or even the person may not be able to remember their own identity. Stress is so extreme that the individual blocks out part of their memory to reduce their anxiety.

The causes of dissociative disorders may involve an attempt to disconnect from consciousness to avoid awareness of traumatic or painful experiences. It may be an at temp to protect the self from this trauma. Severe and continual physical or sexual abuse as a child is a prom in ant precursor to dissociative identity disorders.

Major dissociative disorders include the following:

Dissociative amnesia involves partial or total memory loss. This is usually caused by overwhelming stress. Amnesia is usually limited to memories associated with anxiety-producing or traumatic events that result in a strong, negative emotional reaction. This disorder is rare.

Dissociative fugue (or generalized amnesia) involves memory and identity loss. The individual may their home and past life for days to years. This is extremely rare.

Dissociative identity disorder (DID) was previously called multiple personality disorder or MPD. This involves the two or more distinct personalities inhabiting the same body. Identities can be either sex and handedness sometimes switches. Brain studies indicate that eye-muscle balance and visual acuity are different in the different personalities; this study was compared to subjects pretending to be have multiple identities in which there were no differences in these factors. This disorder is extremely rare.

There is still some skepticism regarding the existence of DID. Only a few cases were reported prior to 1970; thousands have been reported in the 1990s. Some psychologists believe DID is a legitimate disorder; others believe it is a form of attention-seeking role playing. Others believe these alternate personalities are a result of therapy. To help deal with a history of abuse, therapists promote the enactment of alternate personalities to cope with these feelings; patients identify too closely with this role and it becomes reality to them.


Mood disorders (also called affective disorders) involve extremes in emotion.

The causes of depression are explained from different perspectives:

biological: disorders are the result of organic causes, particularly levels of seritonin and norepinephrine
behavioral: feelings result from lack of positive reinforcement and an overabundance on punishment; this is an imbalance between behavioral output and reinforcement input; this becomes a viscous cycle as behavior diminishes and reinforcement is consequently absent
cognitive: feelings are caused by negative thinking, pessimistic views of self and the world; this becomes a distorted thinking pattern and a mental filter that bias people toward exaggerating events and conflicts
psychodynamic: anxiety disorders are the result of an unresolved childhood emotions and unconscious conflicts; Freud believed depression was anger turned inward against one's self
Additionally, the learned helplessness model believes that people become depressed when they believe they cannot control the reinforcement in their lives. This is combined with attributional style which refers to where people place the cause of events: internal or external factors, global or specific factors, and stable or unstable factors. Depressive attributional style consists of internal, global and stable attributions; this means the person thinks that negative situation are because they are at fault (internal), they don't possess the abilities to deal with the issue (global) and they'll never learn to cope with them (stable).

Major mood disorders include the following:

Major depressive disorder involves feelings of worthlessness, a depressed mood and a reduction in pleasure from most activities for a period of at least two weeks. This is an extreme depression, not to be confused with feeling blue from time to time. Lifetime prevalence: 10-25% for women and 5-12% for men.

Seasonal affective disorder (SAD) is a pattern of severe depression in the fall and winter, and elevated moods in the spring and summer; this has been successfully treated with artificial light therapy.

Dysthymic disorder is a mild, chronic depression for long period of time, typically five years or more. Lifetime prevalence: 6%.

Mania is a period of hyperactivity where the individual has unrealistic hope and dreams. It is an wildly optimistic, euphoric state. When this manic behavior is coupled with depression, the individual experiences bipolar disorder. This is extreme mood swings between both mania and depression. Bipolar disorder is rare; lifetime prevalence: .4-1.6%.

Cyclothymic disorder is a milder form of bipolar disorder, with less severe swings in mood. Unlike unipolar depression which is more common in women, bipolar and cyclothymic disorder are equally common among both men and women.


Schizophrenia is a collection of several disorders that are characterized by disorganized thinking and language, delusions (or false beliefs), hallucinations (or false sensory experiences), and grossly inappropriate behavior. Schizophrenic has a flattened affect (or lack of emotional dynamic) and tend to become withdrawn from social settings. Life prevalence: 1%.

The causes of schizophrenia fall predominantly around the biological model. In fact, Freud did not have any good explanation for schizophrenia.

In terms of genetic factors, one stands a 13% chance of developing schizophrenia if one of his or her parents is schizophrenic, and a 45- 50% chance if his or her identical twin suffers from the disorder. If heredity was the sole factor, it would be expected that fraternal twins would have a 100% chance of both being schizophrenic. In fraternal twins there is about a 17% chance if one has schizophrenia that the other will as well. These statistics have been supported through adoption studies as well.
Biochemical factors involve overreactivity or overabundance of dopamine levels in the brain. The brain does not have more dopamine, rather schizophrenia patients seem to have more dopamine receptors and these may be overly sensitive. Excess dopamine promotes hallucinations and delusional thinking. Antipsychotic drugs such as Thorazine and Mellaril reduce dopamine activities.
Brain abnormalities also seem to contribute to schizophrenia. These abnormalities develop during certain critical prenatal periods. Areas that are most effected are the prefrontal cortex (thought formation and organization) and the limbic system (memory and emotion).
The diathesis-stress model suggests that stress works with genetic factors in bringing on schizophrenia in genetically vulnerable individuals. Sources of stress include early brain trauma, dysfunctional family environments and negative life events. It is suggested that these factors combine to produce brain abnormalities and disturbances in thinking, memory and perception.

Schizophrenia is frequently confused with dissociative identity disorder because the word "schizophrenia" literally means "split mind." This is because their is a break with reality and a disintegration of personality. Because of this, schizophrenic disorders are considered psychotic disorders.

Schizophrenia is usually diagnosed in the late teens or early twenties and occurs in only 1% of the population. There is a fairly strong genetic link to schizophrenia and recent research believes the limbic system is involved in the disorder.

25% of those who experience a schizophrenic episode fully recover, 50% have reoccurances which can be controlled through medication, and 25% show little to no sign of recovery.

Schizophrenia can be one of two types: process (or chronic) schizophrenia develops gradually over time while reactive (or acute) schizophrenia comes on suddenly, usually in response to environmental cues. Prognosis is worse for process schizophrenia and better for reactive schizophrenia.

Some schizophrenic patients have positive symptoms which include excessive laughing and emotional outbursts as well as disorganized speech and thinking. Those exhibiting these symptoms tend to have normal brain structures but excessive amounts of dopamine, show overactivity and aggressive behavior during adolescence and have a greater prognosis for treatment.

Other patients have negative symptoms which include rigid bodies, lack of emotional response and faces with no expression. Those exhibiting these symptoms tend to have more abnormal brain structures, more frontal and parietal lobe deficits, are more clearly genetically linked, have lower educational levels and a poorer prognosis for treatment.

The major types of schizophrenia are:

paranoid: fear or persecution is present, as are delusions of grandeur, or feelings of extreme self-importance as the reason they are being singled out for persecution
disorganized: disorganized thinking and speech patterns accompanied by flat emotions and/or grossly inappropriate behavior
catatonic: a freezing up of the body in response to overwhelming stress accompanied by extreme negativism and/or mimicking of language patterns or body movements
undifferentiated (residual): schizophrenic symptoms that do not fit one of the specific types listed above


Personality disorders involve enduring, inflexible behavior patterns that impair social functioning. These are usually first identified in adolescence and 10-20% of the population has one type of personality disorder.

The DSM-IV classifies three types of personality disorder:

Group 1
paranoid personality disorder: extreme suspiciousness and mistrust of others based on unjustified reasoning
schizoid personality disorder: indifference or lack of interpersonal relationships
Group 2
narcissistic personality disorder: an overexaggeration of self-importance and love of one's self; requires constant attention and admiration
antisocial personality disorder: exercises his or her own needs or wants over the feelings of others; hedonistic (seeks self-gratification); no emotional reaction to others' suffering; commonly called a psychopath or sociopath
histrionic personality disorder: over-dramatizes situations and behaviors; blows things out of proportion and overreacts to situations
Group 3
dependent personality disorder: overly dependent on others due to low self-esteem and lack of confidence
avoidant personality disorder: avoids relationships because of an exaggerated fear of rejection


Organic disorders are sometimes mistaken for psychological disorders. These organic disorders include dementia in Alzheimer’s disease, vascular dementia, organic amnesia (not induced by alcohol or other substances, brain disease, brain damage, and brain dysfunction.


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