Psychosis

BASICS

DESCRIPTION

A disorder where thoughts and emotions are disrupted; seen in schizophrenia, mood disorders, substance use, medical problems, delirium, and dementia

  • Positive symptoms: hallucinations and delusions (fixed false beliefs not typical of cultural background)
  • Negative symptoms: anhedonia, poverty of speech, lack of motivation, social withdrawal, affective blunting
  • Cognitive symptoms: poor working memory, information processing, inattention, disorganized speech and/or behavior

EPIDEMIOLOGY

Prevalence

  • Schizophrenia: peak onset: males: ages 18 to 25 years; females: ages 25 to 35 years
  • 1% of the general population; ~50% of bipolar and 20% of unipolar depression cases

ETIOLOGY AND PATHOPHYSIOLOGY

  • Many causes including psychiatric, medical, and/or substance use
  • Positive symptoms: excessive dopaminergic activity in the mesolimbic pathway
  • Negative symptoms: diminished dopaminergic activity in mesocortical pathway
  • Cognitive symptoms: neurodevelopmental factors including childhood trauma, neurodegenerative factors such as smoking, obesity, and cortical disinhibition

Genetics

Schizophrenia: 50% concordance in monozygotic twins; many genes involved

RISK FACTORS

Family history, substance use (e.g., stimulants, THC), lower socioeconomic status

GENERAL PREVENTION

Community interventions for early detection and treatment of prodromal symptoms.

COMMONLY ASSOCIATED CONDITIONS

  • Associated with metabolic syndrome, autonomic dysfunction, sudden cardiac death, and breast and lung cancer
  • Substance use, including nicotine dependence

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