Psychological disorders vary in their impact on thinking, emotion, and behavior, and identifying core categories aids in early recognition, diagnosis, and intervention.
Neurodevelopmental Disorders
Neurodevelopmental disorders are a group of conditions that originate in the developmental period, often before the child enters grade school. These disorders manifest early in life and typically produce impairments in personal, social, academic, or occupational functioning. They result from disturbances in brain development, affecting areas such as language, motor skills, behavior, learning, and social interaction.
Key Features
Early onset: Symptoms are usually present in the preschool years and persist across developmental stages.
Persistent and pervasive effects: These disorders interfere with everyday functioning in multiple domains, including education, family life, and friendships.
Variable presentation: Severity and specific symptoms can differ widely between individuals, even with the same diagnosis.
Common Neurodevelopmental Disorders
Attention-Deficit/Hyperactivity Disorder (ADHD)
ADHD is marked by a consistent pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development.
Inattention symptoms include:
Failing to pay close attention to details
Difficulty sustaining attention in tasks or play
Seeming not to listen when spoken to directly
Forgetfulness and disorganization
Hyperactivity and impulsivity symptoms include:
Fidgeting or squirming in seats
Talking excessively
Interrupting others
Difficulty waiting for one’s turn
Autism Spectrum Disorder (ASD)
ASD includes a wide range of symptoms and severity but is generally characterized by deficits in social communication and interaction, along with restricted and repetitive patterns of behavior.
Difficulty understanding nonverbal communication
Challenges with developing and maintaining relationships
Insistence on sameness and inflexible routines
Highly fixated interests and sensory sensitivities
Causes
Environmental Factors
Prenatal exposure to toxins like alcohol, lead, and certain medications can disrupt brain development.
Premature birth or low birth weight increases the risk of developmental complications.
Maternal infections or stress during pregnancy can influence fetal neurodevelopment.
Biological Influences
Differences in brain regions such as the prefrontal cortex and cerebellum can affect attention, impulse control, and social behavior.
Neurotransmitter imbalances, especially involving dopamine and serotonin, are implicated in ADHD and ASD.
Genetic Contributions
A family history of ADHD or ASD increases the likelihood of diagnosis.
Specific gene mutations, such as those affecting synaptic connectivity, are linked to these disorders.
Schizophrenic Spectrum Disorders
Schizophrenic spectrum and other psychotic disorders involve significant alterations in cognition, emotion, and perception. They often impair a person’s ability to distinguish between what is real and what is not. These disorders may develop gradually or suddenly and can be episodic or chronic.
Core Symptoms
Positive Symptoms (excesses or distortions of normal functioning):
Delusions: Firmly held false beliefs that are resistant to reason or contrary evidence.
Examples include:
Persecutory delusions: Belief that others are plotting to harm them
Grandiose delusions: Belief in possessing special powers or fame
Hallucinations: Perceptions without external stimuli, often auditory, such as hearing voices
Disorganized thinking and speech: Jumping between unrelated topics (loose associations), incoherence, or "word salad"
Disorganized motor behavior: May range from agitation to catatonia, which includes lack of movement or repeated purposeless actions
Negative Symptoms (loss of normal functions):
Flat affect: Reduced emotional expressiveness
Alogia: Minimal speech output
Avolition: Lack of initiative and motivation
Anhedonia: Inability to experience pleasure
Causes
Genetic Risk
First-degree relatives of individuals with schizophrenia have a higher probability of developing the disorder.
Twin and adoption studies support a strong heritable component.
Biological Factors
The dopamine hypothesis suggests that overactivity of dopamine in certain brain areas contributes to symptoms.
Brain imaging reveals enlarged ventricles, decreased frontal lobe activity, and reduced gray matter.
Environmental Triggers
Prenatal exposure to viral infections or malnutrition
Stressful life events or drug abuse, particularly during adolescence, can trigger symptoms in genetically vulnerable individuals
Obsessive-Compulsive and Related Disorders
These disorders involve unwanted repetitive thoughts (obsessions) and/or behaviors (compulsions) performed in response to the obsessions to reduce anxiety.
Common Disorders
Obsessive-Compulsive Disorder (OCD)
Obsessions: Persistent thoughts, urges, or images that are intrusive and unwanted
Compulsions: Repetitive behaviors or mental acts performed to prevent or reduce distress
Individuals recognize the irrational nature of their behaviors but feel compelled to perform them
Hoarding Disorder
Persistent difficulty discarding or parting with possessions
Leads to accumulation of clutter that disrupts living spaces and causes distress
Contributing Factors
Learning Theories
Classical conditioning: Neutral stimuli become associated with fear or anxiety
Operant conditioning: Compulsive behaviors are negatively reinforced by anxiety reduction
Cognitive Distortions
Inflated responsibility: Belief that failing to act will result in harm
Thought-action fusion: Believing that thinking about an action is morally equivalent to doing it
Need for certainty: Inability to tolerate ambiguity
Biological and Genetic Factors
Imbalances in serotonin and dopamine
Overactivity in brain areas such as the orbitofrontal cortex, anterior cingulate cortex, and basal ganglia
A family history of OCD increases risk
Dissociative Disorders
Dissociative disorders disrupt the normal integration of consciousness, memory, identity, and perception. They are often triggered by trauma or extreme stress and serve as a defense mechanism.
Types and Symptoms
Dissociative Amnesia
Inability to recall personal information, especially related to trauma
May involve localized, selective, or generalized amnesia
Dissociative Fugue
Sudden travel away from home with memory loss about one’s identity
May assume a new identity without awareness of the previous one
Dissociative Identity Disorder (DID)
Presence of two or more distinct identity states
Disruption in sense of self and gaps in memory
Each identity may have unique behaviors, memories, and even physiological responses
Depersonalization/Derealization
Depersonalization: Feeling detached from one’s thoughts, body, or actions
Derealization: Feeling that the external world is unreal or dreamlike
Causes
Trauma and Abuse
Repeated childhood abuse is the most common precipitating factor
Dissociation serves as a coping mechanism to escape unbearable situations
Chronic Stress and Emotional Neglect
Lack of stable caregiving, safety, or emotional validation disrupts identity development
Biological Vulnerabilities
Genetic predisposition
Brain imaging studies show irregularities in regions involved in emotion and memory processing, such as the hippocampus and amygdala
Trauma and Stressor-Related Disorders
These disorders occur after exposure to traumatic or extremely stressful events. The most well-known example is Posttraumatic Stress Disorder (PTSD).
Symptoms of PTSD
Intrusive memories: Flashbacks, distressing dreams, or intrusive thoughts
Avoidance behaviors: Avoiding reminders of the trauma (people, places, activities)
Negative mood and cognition: Persistent guilt, blame, estrangement from others
Hyperarousal symptoms: Irritability, exaggerated startle response, insomnia
Duration and Impact
Symptoms must persist for more than one month to meet diagnostic criteria
Can cause significant impairment in academic, occupational, and social functioning
Causes
Traumatic Exposure
Direct experience of or witnessing of violence, injury, or sexual assault
Secondary exposure through repeated exposure to trauma-related content (e.g., emergency workers)
Cognitive and Emotional Factors
Preexisting anxiety or depression
Ineffective coping strategies
Self-blame and distorted beliefs about safety and trust
Biological Contributions
Dysregulated cortisol and norepinephrine levels
Overactivation of the amygdala, underactivation of the prefrontal cortex
Reduced hippocampal volume, impairing memory consolidation
Feeding and Eating Disorders
Feeding and eating disorders involve disturbed eating behaviors that result in significant health complications and psychological distress. These disorders commonly begin during adolescence.
Key Disorders
Anorexia Nervosa
Severe restriction of calorie intake
Intense fear of gaining weight despite being underweight
Distorted body image
Can lead to organ failure, osteoporosis, and electrolyte imbalances
Bulimia Nervosa
Episodes of binge eating followed by compensatory behaviors
Compensatory behaviors include vomiting, fasting, or excessive exercise
Binge episodes are marked by a sense of loss of control
Physical effects include dental erosion, esophageal damage, and electrolyte imbalance
Contributing Factors
Biological Factors
Neurotransmitter imbalances (low serotonin and dopamine)
Hormonal dysregulation affecting hunger cues
Genetic risk, especially if a family member has an eating disorder
Psychological Influences
Perfectionism and low self-worth
Anxiety disorders or depression
Cognitive distortions about body size and control
Sociocultural Pressures
Cultural glorification of thinness
Media portrayal of unrealistic beauty ideals
Peer influence and diet culture
Personality Disorders
Personality disorders involve enduring, inflexible patterns of inner experience and behavior that deviate markedly from cultural expectations. These patterns emerge in adolescence or early adulthood and cause impairment or distress.
Cluster A: Odd or Eccentric
Paranoid Personality Disorder
Distrust and suspicion of others’ motives
Belief that others are exploiting or deceiving them
Reluctance to confide in others
Schizoid Personality Disorder
Detachment from social relationships
Preference for solitary activities
Indifference to praise or criticism
Schizotypal Personality Disorder
Social and interpersonal deficits
Magical thinking, unusual perceptions, and odd speech
Discomfort in close relationships
Cluster B: Dramatic, Emotional, or Erratic
Antisocial Personality Disorder
Disregard for social norms and rights of others
Deceitfulness and impulsivity
Lack of empathy and remorse
Borderline Personality Disorder
Instability in relationships, self-image, and emotions
Fear of abandonment
Self-harm and suicidal behavior
Histrionic Personality Disorder
Excessive emotionality and attention-seeking
Shallow, rapidly shifting emotions
Easily influenced by others
Narcissistic Personality Disorder
Grandiosity and need for admiration
Lack of empathy
Hypersensitivity to criticism
Cluster C: Anxious or Fearful
Avoidant Personality Disorder
Social inhibition due to feelings of inadequacy
Fear of criticism or rejection
Desire for relationships despite avoidance
Dependent Personality Disorder
Excessive need to be cared for
Difficulty making decisions without reassurance
Submissive and clingy behavior
Obsessive-Compulsive Personality Disorder (OCPD)
Preoccupation with order, perfection, and control
Inflexibility about morality and ethics
Reluctance to delegate tasks
Causes
Genetic and Neurological Factors
Higher prevalence among first-degree relatives
Abnormalities in brain areas related to emotion regulation and decision-making
Serotonin dysfunction linked to impulsivity and mood instability
Developmental and Environmental Influences
Childhood trauma, neglect, or abuse
Dysfunctional family dynamics
Cultural or societal pressure to conform to rigid standards or expectations
FAQ
Personality disorders are diagnosed based on long-standing patterns of behavior, cognition, and inner experience that deviate from cultural expectations and emerge in adolescence or early adulthood. Unlike mood or anxiety disorders, which often involve episodic symptoms like panic attacks or depressive episodes, personality disorders involve enduring traits that persist over time and across situations. Diagnosis typically involves:
Clinical interviews assessing long-term behavioral patterns and relationships.
Evaluations of how personality traits affect daily functioning.
Ruling out other disorders or medical conditions that may mimic symptoms.
Assessing whether the traits cause distress or impair work, social, or personal functioning.
Observing consistency over time, unlike mood disorders which may fluctuate.
Though all three disorders involve disruptions in thought or identity, their core features and causes differ. Dissociative Identity Disorder (DID) is characterized by two or more distinct identity states, often formed as a coping mechanism in response to trauma. In contrast:
Schizophrenia involves psychotic symptoms like hallucinations and delusions, with a biological basis in brain chemistry and structure.
Bipolar disorder features cycles of depression and mania, not distinct personalities or identity fragmentation.
DID often lacks hallucinations but may include amnesia and depersonalization.
Individuals with schizophrenia typically lack insight into their condition, while those with DID are more likely to recognize their identity disruptions.
OCD and OCPD share similarities in rigidity and preoccupation with order, but they differ significantly in motivation, self-awareness, and behavioral patterns:
OCD involves distressing, intrusive thoughts (obsessions) and repetitive behaviors (compulsions) to relieve anxiety. Individuals recognize their behaviors as irrational.
OCPD is a personality disorder marked by chronic perfectionism, control, and orderliness, often viewed by the person as appropriate or beneficial.
People with OCPD are typically unaware that their behavior is problematic (ego-syntonic), whereas OCD sufferers experience significant distress (ego-dystonic).
OCPD behaviors are pervasive across life contexts, while OCD rituals are usually more situation-specific.
OCD typically requires behavioral or pharmacological treatment, while OCPD may respond better to long-term psychotherapy.
Cultural norms, values, and social expectations can shape how disorders present and how they are perceived, diagnosed, and treated. For instance:
Eating disorders may be more prevalent in Western societies that idealize thinness, contributing to higher rates of anorexia or bulimia.
Personality traits considered disordered in one culture may be seen as acceptable or even valued in another (e.g., independence vs. collectivism).
Cultural stigma can delay diagnosis or lead to underreporting, especially in communities where mental illness is taboo.
Clinicians must be trained in cultural competence to avoid misdiagnosis or overlooking symptoms influenced by cultural expression.
Cultural syndromes (e.g., ataque de nervios, kufungisisa) may resemble Western psychiatric categories but require nuanced interpretation.
Yes, comorbidity is common in clinical psychology and refers to the simultaneous presence of two or more psychological disorders in an individual. Examples include:
A person with ADHD (a neurodevelopmental disorder) may also suffer from depression or anxiety.
Someone with schizophrenia may also develop substance use disorder or OCD symptoms.
Dissociative symptoms may co-occur with trauma-related disorders, particularly when early abuse is involved.
Comorbidity can complicate diagnosis and treatment, requiring a multi-faceted approach to address overlapping symptoms.
Understanding the interaction between disorders is essential for effective intervention, as treating one disorder might not resolve others without comprehensive care.
Practice Questions
Explain how biological and environmental factors interact in the development of neurodevelopmental and obsessive-compulsive disorders. Provide one example of each.
Biological and environmental factors interact to influence the development of both neurodevelopmental and obsessive-compulsive disorders. In ADHD, a neurodevelopmental disorder, genetic predispositions such as inherited neurotransmitter imbalances in dopamine systems may combine with environmental influences like prenatal exposure to alcohol or maternal stress to impair attention and impulse control. For obsessive-compulsive disorder, individuals may inherit abnormalities in serotonin regulation or brain structures involved in habit formation, while also learning compulsive behaviors through negative reinforcement or observing others. This interaction emphasizes that both inherited vulnerabilities and life experiences shape how these disorders emerge and persist across individuals’ development.
Differentiate between positive and negative symptoms of schizophrenic spectrum disorders. Provide one example of each and explain how they impact daily functioning.
Positive symptoms of schizophrenic spectrum disorders involve the addition of abnormal behaviors, while negative symptoms reflect a reduction or absence of typical behaviors. A common positive symptom is hallucinations, such as hearing voices that aren't present, which can distract individuals and impair concentration. A negative symptom, like flat affect, involves limited emotional expression, making social interactions difficult and isolating. Positive symptoms often draw attention and require immediate treatment due to distress, whereas negative symptoms may hinder motivation and long-term functioning. Both types significantly disrupt daily life, from maintaining relationships to holding employment, and require comprehensive treatment strategies.
