Rare diseases · Sign or symptom
Apathy
Lack of feeling, emotion, interest
HP:0000741
What it means
Apathy is a quantitative reduction of interest, motivation and the initiation and persistence of goal-directed behavior, where often the accompanying emotions, thoughts, and social interactions are also diminished. The individual is typically non-reactive to provocations, positive or negative, and appears to not care. Distinguished from lethargy which involves lack of physical or mental energy.
Apathy may co-occur with lethargy.
Rare diseases that can present with this44
Common30–79%
18- 3-hydroxy-3-methylglutaric aciduria
- African trypanosomiasis
- Alobar holoprosencephaly
- Benign paroxysmal torticollis of infancy
- Beta-ketothiolase deficiency
- CADASIL
- Cyanide-induced parkinsonism-dystonia
- Frontotemporal dementia with motor neuron disease
- Huntington disease
- Inherited Creutzfeldt-Jakob disease
- Kleine-Levin syndrome
- Midline interhemispheric variant of holoprosencephaly
- Multiple system atrophy, parkinsonian type
- PRKAR1B-related neurodegenerative dementia with intermediate filaments
- Progressive supranuclear palsy
- Progressive supranuclear palsy-progressive non-fluent aphasia syndrome
- Semilobar holoprosencephaly
- Young-onset Parkinson disease
Sometimes5–29%
21- Aceruloplasminemia
- Behavioral variant of frontotemporal dementia
- CACH syndrome
- Cerebral autosomal recessive arteriopathy-subcortical infarcts-leukoencephalopathy
- Choreoacanthocytosis
- Hereditary late-onset Parkinson disease
- Kleefstra syndrome due to 9q34 microdeletion
- Kufor-Rakeb syndrome
and 13 more in this range
The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
Also called: Lack of feeling, emotion, interest, motivation, initiation · State of indifference
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Start free with EleplanThis page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.