What Is a Psychological Disorder?

  • Criteria for defining psychological disorders depend on whether cultural norms are violated, whether behavior is maladaptive or harmful, and whether there is distress.
  • The medical model describes and explains psychological disorders as if they are diseases.
  • The vulnerability-stress model states that disorders are caused by an interaction between biological and environmental factors.
  • The learning model theorizes that psychological disorders result from the reinforcement of abnormal behavior.
  • The psychodynamic model states that psychological disorders result from maladaptive defenses against unconscious conflicts.
  • Psychologists use objective and projective tests to assess psychological disorders.


  • Classification allows psychologists to describe disorders, predict outcomes, consider treatments, and study etiology.
  • Insanity is a legal term, not a diagnostic label.
  • Psychologists and psychiatrists use the DSM to diagnose psychological disorders.
  • The DSM uses a multi-axial system of classification.
  • The DSM is a useful tool but has been criticized for several reasons.
  • Most of the major disorders in the DSM are found worldwide.
  • Culture-bound syndromes are limited to specific cultural contexts.

Anxiety Disorders

  • A chronic, high level of anxiety may be a sign of an anxiety disorder.
  • Generalized anxiety disorder involves persistent and excessive anxiety for at least six months.
  • Having a specific phobia means becoming anxious when exposed to a specific circumstance.
  • Social phobia is characterized by anxiety in social or performance situations.
  • A person with panic disorder experiences recurrent, unexpected panic attacks.
  • Agoraphobia involves anxiety about having panic attacks in difficult or embarrassing situations.
  • Obsessive-compulsive disorder entails obsessions, compulsions, or both.
  • Post–traumatic stress disorder is a set of psychological and physiological responses to a highly traumatic event.
  • Biological factors implicated in the onset of anxiety disorders include genes, different sensitivity to anxiety, the neurotransmitters GABA and serotonin, and brain damage.
  • Conditioning and learning may contribute to the development of phobias.
  • Some styles of thinking may make people more susceptible to anxiety disorders.
  • Neuroticism is associated with anxiety disorders.

Mood Disorders

  • Mood disorders are characterized by marked disturbances in emotional state, which cause physical symptoms and affect thinking, social relationships, and behavior.
  • Mood disorders may be unipolar or bipolar.
  • People with dysthymic disorder have depressed mood for at least two years.
  • Major depressive disorder involves at least one period with significant depressive symptoms.
  • Bipolar disorders involve at least one period with manic symptoms and usually depressive periods as well.
  • Biological influences on mood disorders include genes, the neurotransmitters norepinephrine and serotonin, and brain abnormalities.
  • There is a two-way relationship between negative thinking and depression.
  • Cognitive characteristics of depressed people include learned helplessness; a pessimistic worldview; hopelessness; a tendency to make internal, stable, global attributions; and a tendency to ruminate.
  • There is a two-way relationship between social support and depression.
  • Depression may be related to experiences of loss.
  • The onset and course of mood disorders may be influenced by stress.

Eating Disorders

  • Eating disorders are characterized by problematic eating patterns, concerns about body weight, and inappropriate efforts to control weight.
  • Anorexia nervosa entails very low body weight, fear of gaining weight, and distorted body image.
  • Bulimia nervosa involves binge eating and unhealthy efforts to control body weight.
  • Some people may have a genetic vulnerability to eating disorders.
  • Eating disorders may be associated with particular personality traits.
  • Cultural factors strongly influence the onset of eating disorders.
  • Lacking autonomy in the family and having an overly weight-conscious mother may influence the onset of eating disorders.
  • People with eating disorders tend to have certain distortions of thinking.
  • The onset of anorexia nervosa may be associated with stressful events.

Somatoform Disorders

  • Somatoform disorders are characterized by real physical symptoms that cannot be fully explained by a medical condition, the effects of a drug, or another mental disorder.
  • A person with somatization disorder has many different, recurrent physical symptoms.
  • Conversion disorder involves symptoms that affect voluntary motor functioning or sensory functioning.
  • People with hypochondriasis constantly fear that they may have a serious disease.
  • People with histrionic personality traits may be more likely to develop somatoform disorders.
  • Several cognitive factors may contribute to somatoform disorders.
  • People with somatoform disorders may learn to adopt a sick role.

Substance-Related Disorders

  • Many substance-related disorders are described in the DSM.
  • Substance abuse is a maladaptive pattern of drug use that results in repeated, negative legal, social, occupational, or academic consequences.
  • Substance dependence involves continuing to use a drug despite persistent harmful physical or psychological consequences.
  • The disease model of addiction holds that addiction is a disease that must be treated medically.
  • The learning model of addiction holds that addiction is a way of coping with stress.
  • Genes may produce a predisposition to substance dependence.
  • Several lines of evidence suggest that environmental factors play a key role in substance dependence.


  • Schizophrenia is a psychotic disorder that includes positive and negativesymptoms. There are several subtypes of schizophrenia.
  • The paranoid type is characterized by marked delusions or hallucinations and relatively normal cognitive and emotional functioning.
  • The disorganized type involves disorganized behavior, disorganized speech, and emotional flatness or inappropriateness.
  • The catatonic type is characterized by unnatural movement or speech patterns.
  • A diagnosis of undifferentiated type applies if diagnostic criteria are not met for any of the above three subtypes.
  • Research suggests that genes, neurotransmitters, and brain abnormalities are involved in the onset of schizophrenia.
  • Stress may help to induce schizophrenia in people who are already biologically vulnerable to the disorder.

Dissociative Disorders

  • Dissociative disorders are characterized by disturbances in consciousness, memory, identity, and perception.
  • Dissociative fugue involves sudden and unexpected travel away from home, failure to remember the past, and confusion about identity.
  • People with dissociative identity disorder fail to remember important personal information and have two or more identities or personality states that control behavior.
  • Dissociative identity disorder is a controversial diagnosis. Psychologists disagree about why its prevalence has risen since the 1980s.
  • Severe stress may play a role in the onset of dissociative disorders.

Personality Disorders

  • Personality disorders are stable patterns of experience and behavior that differ noticeably from patterns that are considered normal by a person’s culture.
  • People with schizoid personality disorder are socially withdrawn and have restricted expression of emotions.
  • Borderline personality disorder involves impulsive behavior and unstable relationships, emotions, and self-image.
  • Histrionic personality disorder is characterized by attention-seeking behavior and shallow emotions.
  • People with narcissistic personality disorder have an exaggerated sense of importance, a strong desire to be admired, and a lack of empathy.
  • Avoidant personality disorder involves social withdrawal, low self-esteem, and extreme sensitivity to being evaluated negatively.
  • Antisocial personality disorder begins at age fifteen and includes a lack of respect for other people’s rights, feelings, and needs.
  • Abnormalities in physiological arousal, a genetically inherited inability to control impulses, and brain damage may be involved in the development of antisocial personality disorder.
  • Environmental influences are also likely to influence the development of antisocial personality disorder.

Popular pages: Psychological Disorders