7 Old age psychiatry7.5 Mental disorders in older people
7.5.10 Other mental disorders in later life
4 min read2 figures
Written by Resident Doctor Committee · Published
Classifying dementia
Degenerative dementias result from intrinsic, progressive loss of neurons.
Non-degenerative dementias are driven by a secondary process such as alcohol, hydrocephalus, haematoma, or a metabolic or infective cause, and they stop or reverse once that process is removed.
Cortical dementias act on the cortex. Subcortical dementias act on the basal ganglia, brainstem or deep white matter.
Pick disease is a cortical dementia: a frontotemporal lobar degeneration with tau-positive Pick bodies in the frontal and anterior temporal cortex.
Dementia starting before 65
Alzheimer's disease is the commonest cause, ahead of vascular, frontotemporal, alcohol-related and Lewy body dementia.
Frontotemporal and alcohol-related dementia make up a larger share of cases before 65 than in later life.
Telling specific causes apart
Condition | Distinguishing feature |
|---|---|
CADASIL | NOTCH3 gene on chromosome 19; migraine with aura in early adulthood, subcortical ischaemic events in midlife, autosomal dominant family history of stroke and dementia |
MELAS | Maternal inheritance and multisystem disease |
Creutzfeldt-Jakob disease | Periodic biphasic or triphasic complexes on a low-voltage electroencephalogram background |
Progressive supranuclear palsy | Supranuclear vertical gaze disorder, which sets it apart from other Parkinson-plus syndromes: vertical saccades slow, then downgaze becomes restricted |
Neurological signs
Scanning (ataxic) dysarthria follows cerebellar degeneration: syllables are broken apart with equal, excessive stress, explosive bursts of loudness and slurred articulation.
Pseudobulbar affect is involuntary crying or laughing that is out of proportion to its trigger and incongruent with mood.
Transient global amnesia
Transient global amnesia is a discrete, self-limited episode of isolated anterograde amnesia lasting hours, with full recovery within a day.
The person asks the same questions repeatedly but stays alert and knows who they are.
Attention and working memory are spared, so a simple span test is normal, while new memories fail to form.
Charles Bonnet syndrome
Charles Bonnet syndrome is complex visual hallucinations with retained insight in a person with visual loss from an eye or visual pathway disorder.
It affects about one in five people with significant sight loss.
Macular degeneration is the commonest cause; glaucoma, cataract and diabetic retinopathy also cause it.
Social isolation is a risk factor alongside visual loss, because it reduces social and sensory stimulation and causes cortical deafferentation.
Diogenes syndrome and hoarding
Diogenes syndrome is gross self-neglect with domestic squalor, hoarding of rubbish (syllogomania), poor insight and refusal of help, usually in older people living alone.
Hoarding disorder is marked by difficulty discarding and attachment to possessions, and it can coexist with squalor.
Hoarding often comes to attention after a fall, fire or housing concern; assess self-neglect, cognition, alcohol use and home safety.
Onset pattern
Symptoms that persist from earlier life need assessment of function, physical harm and new features; imaging is not routine for longstanding symptoms alone.
First onset after 65, or atypical onset, raises concern for physical disease, drugs or another psychiatric disorder, and calls for cognitive and physical assessment, medication review and imaging where indicated.
Post-traumatic stress disorder
First presentation often follows years of concealed symptoms, once bereavement, illness or care home admission removes coping strategies.
In dementia, resistance during personal care may reflect re-experiencing an assault.
Offer individual trauma-focused cognitive behavioural therapy, or eye movement desensitisation and reprocessing more than three months after non-combat trauma; age alone is no reason to withhold psychological treatment.
Venlafaxine or a selective serotonin reuptake inhibitor (SSRI) such as sertraline is used when drug treatment is preferred.
Obsessive-compulsive disorder
Most obsessive-compulsive disorder in later life began earlier. Genuinely late onset warrants neurological assessment and consideration of imaging for frontal or basal ganglia lesions, infarction, tumour, injury or neurodegeneration.
Compulsions follow intrusive thoughts and are resisted and then relieved; frontotemporal repetition is simple, stereotyped and unresisted, with apathy, disinhibition and reduced empathy.
Response can take up to twelve weeks to judge. Over 65, citalopram is capped at 20 mg and escitalopram at 10 mg daily because of QT interval risk.
Clomipramine needs particular caution and an electrocardiogram because of its anticholinergic and cardiac effects.
Bodily distress and eating disorders
ICD-11 bodily distress disorder does not require medically unexplained symptoms; the problem is excessive attention, distress or behaviour about symptoms.
Late-onset hypochondriacal preoccupation may reflect depression, and nihilistic beliefs about absent or rotting organs suggest psychotic depression.
Weight loss in later life may come from malignancy, dysphagia, depression, dementia, drugs, dental disease or dependence on others, as well as an eating disorder.
With frailty, complications appear before body mass index looks alarming; check phosphate, potassium and magnesium for refeeding risk.