Neuropsychiatric symptoms represent a core feature of progressive supranuclear palsy (PSP), significantly impacting quality of life, functional independence, and caregiver burden. Unlike the motor symptoms that define the diagnostic criteria, neuropsychiatric manifestations often appear early in the disease course—sometimes years before the characteristic vertical gaze palsy or postural instability emerge—providing important insights into disease progression and neurobiological underpinnings.
¶ Prevalence and Spectrum
Neuropsychiatric symptoms occur in the vast majority of PSP patients:
- Any neuropsychiatric symptom: 70-90% prevalence
- Multiple symptoms: Most patients exhibit 2-5 concurrent symptoms
- Early onset: Symptoms often predate motor diagnosis by 2-3 years
- Disease progression: Symptoms generally worsen over time
The neuropsychiatric profile of PSP includes:
- Mood disorders: Depression, anxiety, apathy
- Behavioral changes: Disinhibition, irritability
- Psychotic features: Hallucinations, delusions
- Personality changes: Emotional blunting
- Motor-related psychiatric symptoms: Pseudobulbar affect
- Prevalence: 30-50% of PSP patients meet criteria for major depression
- Severity: Often moderate to severe
- Atypical features: Less guilt and self-worthlessness than primary depression
- Course: Persistent, often worsening with disease progression
- Orbitofrontal cortex: Reduced gray matter
- Anterior cingulate: Metabolic dysfunction
- Dorsolateral prefrontal cortex: Hypoactivation
- Brainstem nuclei: Serotonergic and noradrenergic dysfunction
- Serotonin: Raphe nuclei involvement
- Norepinephrine: Locus coeruleus degeneration
- Dopamine: Nigrostriatal pathway disruption
- GABA: Basal ganglia inhibitory deficits
- Suicide risk: Elevated in early PSP
- Treatment resistance: Requires multimodal approaches
- Motor impact: Depression worsens bradykinesia and fatigue
- Caregiver burden: Depression predicts caregiver distress
| Intervention |
Evidence Level |
Notes |
| SSRIs |
Moderate |
First-line pharmacotherapy |
| SNRIs |
Moderate |
Venlafaxine, duloxetine |
| TCAs |
Limited |
Caution due to side effects |
| ECT |
Case reports |
For severe, refractory cases |
| Psychotherapy |
Supportive |
Cognitive-behavioral approaches |
- Prevalence: 30-40% clinically significant anxiety
- Types: Generalized anxiety, panic, social anxiety
- Onset: Often early, preceding motor symptoms
- Relationship to disease: Worsens with disability progression
- Motor anxiety: Fear of falling, akinesia-induced panic
- Social anxiety: Embarrassment about symptoms
- Health anxiety: Concern about progression
- Catastrophic reactions: Sudden anxiety with challenges
- Benzodiazepines: Limited use due to fall risk
- SSRIs: First-line for generalized anxiety
- Buspirone: Low fall-risk alternative
- Non-pharmacological: Relaxation, graded exposure
- Prevalence: 50-70% of PSP patients
- Severity: Often profound, resembling abulia
- Distinction from depression: Reduced emotional reactivity
- Distinct from fatigue: Not relieved by rest
- Emotional-affective apathy: Reduced emotional responsiveness
- Cognitive apathy: Reduced goal-directed thinking
- Auto-activation apathy: Difficulty initiating self-care
- Anterior cingulate cortex: Executive and motivational hub
- Orbitofrontal cortex: Reward processing
- Basal ganglia: Motor motivation
- Subthalamic nucleus: Initiative generation
- Medication adherence: Forgetting doses
- Rehabilitation: Limited participation
- Self-care: Neglect of hygiene, nutrition
- Caregiver burden: Major contributor
- Stimulants: Methylphenidate (off-label)
- Dopamine agonists: May improve motivation
- Behavioral interventions: Structured routines
- Environmental modifications: Cues and prompts
- Prevalence: 20-30% in PSP
- Presentation: Involuntary crying or laughing
- Trigger: Minimal stimuli
- Duration: Brief episodes (seconds to minutes)
- Brainstem involvement: Pseudobulbar nuclei
- Cortical inhibition loss: Disinhibited emotional expression
- Neurotransmitter dysregulation: Serotonin, dopamine
- Dextromethorphan/quinidine (Nuedexta): FDA-approved for PBA
- SSRIs: Moderate benefit
- Levodopa: May reduce episodes in some patients
- Prevalence: 15-25% of patients
- Features: Impulsive, socially inappropriate behavior
- Types: Sexual, verbal, physical
- Neuroanatomy: Orbitofrontal dysfunction
¶ Irritability and Aggression
- Prevalence: 20-30%
- Triggers: Frustration, environmental stress
- Manifestations: Verbal outbursts, physical aggression
- Risk factors: Frontal lobe involvement
¶ Pathological Laughter and Crying
- Distinct from PBA: More prolonged, situation-dependent
- Emotional lability: Shifting rapidly between states
- Frontal release signs: Part of subcortical syndrome
- Prevalence: 5-15% in PSP (less common than in PD)
- Types: Visual most common
- Features: Often formed, non-threatening
- Timing: Usually later in disease course
- Prevalence: 5-10%
- Types: Paranoid, jealous, grandiose
- Features: Often related to perceived infidelity or theft
- Impact: Significant distress and conflict
- Anticholinergic medications: Dopamine agonists
- Cognitive impairment: Moderate to severe dementia
- Visual impairment: Charles Bonnet syndrome overlap
- Sleep disorders: REM sleep behavior disorder
- Prevalence: Nearly universal in PSP
- Features: Planning, flexibility, inhibition deficits
- Relationship: Frontal lobe/subcortical involvement
- Prevalence: 80%+ affected
- Impact: Functional independence
- Relationship: Attentional deficits
- Prevalence: 60-70% impaired
- Domain: Verbal and visuospatial
- Progression: Worsens over time
- Prevalence: 20-30% in PSP
- Features: Dream enactment, violent movements
- Polysomnography: REM without atonia
- Importance: May precede motor symptoms
- Prevalence: 50-60%
- Types: Sleep onset, sleep maintenance
- Contributing factors: Nocturnal motor symptoms, depression
- Prevalence: 40-50%
- Causes: Nocturnal disruption, brainstem dysfunction
- Impact: Safety concerns, function
| Symptom |
First-Line |
Alternative |
Caution |
| Depression |
SSRIs |
SNRIs, bupropion |
Anticholinergic effects |
| Anxiety |
SSRIs |
buspirone |
Falls, sedation |
| Apathy |
Behavioral |
stimulants |
Cardiac risk |
| PBA |
Dextromethorphan/quinidine |
SSRIs |
Drug interactions |
| Psychosis |
Quetiapine |
clozapine |
Sedation, blood counts |
- Psychotherapy: Supportive, cognitive-behavioral
- Environmental modifications: Reduce triggers
- Caregiver education: Understanding behavioral changes
- Sleep hygiene: Optimize sleep architecture
- Psychiatry: Diagnosis and medication management
- Psychology: Assessment and therapy
- Occupational therapy: Functional adaptations
- Social work: Resource navigation
- Major determinant: More than motor symptoms
- Caregiver quality: Intertwined with patient QoL
- Functional independence: Neuropsychiatric barriers
- Predictor variables: Depression, psychosis, disinhibition
- Institutionalization: Neuropsychiatric symptoms drive placement
- Caregiver health: Physical and psychological impact
- Disease progression: Neuropsychiatric symptoms predict faster decline
- Mortality: Depression associated with reduced survival
- Treatment response: Complicated by neuropsychiatric features