5.4 Types of Psychological Disorders

Neurodevelopmental Disorders

Group of conditions with onset in development causing deficits in intellectual functioning, language, social skills, and motor skills.

Attention-Deficit/Hyperactivity Disorder (ADHD)

Persistent inattention, hyperactivity, and impulsivity that significantly impair functioning in at least two settings (e.g., home, school).

Autism Spectrum Disorder (ASD)

Persistent deficits in social communication and interaction, plus restricted, repetitive patterns of behavior, interests, or activities.

Schizophrenic Spectrum Disorders

Group of psychotic illnesses marked by hallucinations, delusions, disorganized thinking, and loss of contact with reality; can be acute or chronic.

Delusions

Positive symptom of schizophrenia; persistent, fixed false beliefs (e.g., believing one is being persecuted) not consistent with reality.

Hallucinations

Positive symptom; sensory experiences (seeing, hearing, smelling, tasting, touching) perceived as real but with no external stimulus present.

Word salad

Positive symptom of schizophrenia; severely disorganized, incoherent speech where words are strung together without meaningful connection.

Catatonia

Schizophrenia symptom involving unusual motor behavior — can be a positive symptom (excitement, mimicking) or negative symptom (stupor, immobility).

Catatonic stupor

Negative symptom; extreme unresponsiveness marked by near-total immobility, mutism, and lack of environmental interaction.

Flat affect

Negative symptom of schizophrenia; significant reduction or complete absence of outward emotional expression in face and voice.

Positive symptoms

Schizophrenia features that add distorted experiences absent in healthy people — includes delusions, hallucinations, word salad, and catatonic excitement.

Negative symptoms

Schizophrenia features reflecting a loss of normal functions — includes flat affect, catatonic stupor, reduced motivation, and social withdrawal.

Dopamine hypothesis

Theory that excess activity of the neurotransmitter linked to reward and movement underlies positive schizophrenic features like hallucinations and delusions.

Depressive Disorders

Mood conditions characterized by persistent sadness, loss of interest, and low energy lasting well beyond normal grief or disappointment.

Major Depressive Disorder

At least five signs of depression (including sad mood or loss of interest) present nearly every day for two or more consecutive weeks.

Persistent Depressive Disorder

Milder but chronic mood-low condition (at least two symptoms) lasting a minimum of two years rather than concentrated episodic periods.

Bipolar Disorders

Mood conditions defined by alternating episodes of depression and mania (or hypomania); formerly called manic-depressive disorder.

Bipolar I Disorder

Subtype requiring at least one full manic episode (often alongside major depressive episodes); the most severe of the two subtypes.

Bipolar II Disorder

Subtype involving hypomanic episodes — milder than full mania — and major depressive episodes, but no full manic episodes ever.

Mania

Distinct period of abnormally elevated mood, grandiosity, decreased need for sleep, impulsivity, and reckless behavior lasting at least one week.

Bipolar cycling

The recurring pattern of shifting between depressive and manic (or hypomanic) mood episodes over time.

Anxiety Disorders

Category of conditions marked by persistent, excessive fear or worry disproportionate to actual threat, significantly impairing daily functioning.

Specific phobia

Intense, irrational, persistent fear and avoidance of one particular object or situation that causes significant distress or functional impairment.

Acrophobia

Specific phobia subtype; extreme, irrational fear of heights even when the individual is not in physical danger.

Arachnophobia

Specific phobia subtype; extreme, irrational fear of spiders that triggers avoidance and significant distress upon exposure.

Agoraphobia

Anxiety disorder; fear of situations where escape is difficult or help unavailable, often triggered by fear of having a panic attack.

Panic disorder

Anxiety condition marked by recurrent, unexpected attacks of intense terror plus persistent worry about future attacks interfering with daily life.

Ataque de nervios (culture-bound)

Syndrome among Caribbean/Iberian individuals; trembling, screaming, aggression, and loss of control triggered by specific stressful events, not random fear.

Social anxiety disorder

Intense fear of situations where one might be judged or embarrassed by others, leading to significant avoidance of interpersonal contexts.

Taijin kyofusho (culture-bound)

Japanese syndrome; intense fear of offending or displeasing others through one's appearance, odor, or behavior — rooted in collectivist values.

Generalized anxiety disorder (GAD)

Excessive, uncontrollable worry about multiple topics persisting for six months or more, accompanied by fatigue, irritability, and restlessness.

Obsessive-Compulsive Disorder (OCD)

Characterized by unwanted, intrusive obsessions and/or repetitive compulsions performed to neutralize anxiety from those thoughts.

Hoarding disorder

OCD-related condition; excessive accumulation of possessions of little value and strong inability to discard them, causing impairment.

Obsessions

Persistent, unwanted, intrusive thoughts or urges that generate anxiety; the cognitive component of OCD.

Compulsions

Repetitive behaviors or mental acts performed in response to obsessions in an attempt to reduce anxiety; the behavioral component of OCD.

Dissociative Disorders

Conditions involving disruption or disconnection in memory, consciousness, identity, or perception causing distress and impairment.

Dissociation

Psychological mechanism of detachment from one's thoughts, identity, or surroundings; the core feature underlying all dissociative conditions.

Dissociative amnesia

Inability to recall specific autobiographical memories or a specific time period, without a neurological cause.

Dissociative fugue

Rare, severe amnesia subtype involving total loss of personal history and self-identity; may involve unplanned travel to a new location.

Dissociative Identity Disorder (DID)

Presence of two or more distinct alters with impaired memory between states; linked to severe early trauma; more common in Western cultures.

Posttraumatic Stress Disorder (PTSD)

Trauma-triggered condition with intrusive memories, avoidance of triggers, negative cognitions, and hyperarousal lasting more than one month.

Anorexia nervosa

Eating disorder involving severe caloric restriction, inability to maintain minimum healthy body weight, and distorted body image.

Bulimia nervosa

Eating disorder involving recurrent binge eating followed by compensatory purging behaviors to prevent weight gain.

Personality disorders

Enduring, inflexible patterns of inner experience and behavior deviating from cultural norms, causing distress or dysfunction across contexts.

Cluster A disorders

Personality conditions grouped by odd, suspicious, and eccentric traits; includes paranoid, schizoid, and schizotypal subtypes.

Paranoid personality disorder

Cluster A; pervasive distrust and suspicion of others' motives without psychotic episodes; includes perceptual distortions.

Schizoid personality disorder

Cluster A; detachment from social relationships and a restricted range of emotional expression without psychotic features or social anxiety.

Schizotypal personality disorder

Cluster A; eccentric behavior, unusual beliefs, perceptual distortions, and significant social discomfort — more severe than schizoid.

Cluster B disorders

Personality conditions grouped by dramatic, emotional, and erratic traits; includes antisocial, histrionic, narcissistic, and borderline subtypes.

Antisocial personality disorder

Cluster B; persistent manipulation, deceit, disregard for others' rights, and absence of guilt or remorse; linked to crime.

Histrionic personality disorder

Cluster B; excessive attention-seeking, dramatic emotional expression, and shallow relationships as core distinguishing features.

Narcissistic personality disorder

Cluster B; grandiose sense of self-importance, need for admiration, and lack of empathy; exaggerates accomplishments.

Borderline personality disorder

Cluster B; unstable emotions, impulsive behaviors, intense fear of abandonment, and poor self-esteem as core features.

Cluster C disorders

Personality conditions grouped by anxious and fearful traits; includes avoidant, dependent, and obsessive-compulsive subtypes.

Avoidant personality disorder

Cluster C; feelings of inadequacy and low self-esteem lead to avoidance of social situations despite desire for connection.

Dependent personality disorder

Cluster C; excessive need to be cared for, difficulty functioning independently, and intense fear of rejection or abandonment.

Obsessive-compulsive personality disorder

Cluster C condition (distinct from OCD); preoccupation with orderliness, perfectionism, and control; overdevoted to work, unable to delegate tasks.