Schizotypal Personality Disorder
Classified in DSM-IV and DSM-5 as a personality disorder; ICD-10 instead classifies it within the schizophrenia section, reflecting its recognised association with that illness.
A person with schizotypal personality disorder shares the aloof, isolated quality of schizoid personality disorder, but not quite as completely: they retain some sense of involvement with the world and some capacity to form relationships. At other times they feel cut off from the world, describe experiences of depersonalisation, and withdraw into themselves; during these periods their communication can become odd and their emotional responses can seem out of keeping with the situation. Odd beliefs, ideas of reference, magical thinking, and suspiciousness may all be present, without ever quite reaching the fixed, unshakeable quality of true delusion.
This has traditionally been classified alongside schizophrenia itself, rather than with the other personality disorders, precisely because of this close association, and distinguishing it from a genuine schizophrenia prodrome is recognised as one of the harder judgement calls in this area.
Recognition features
- Aloofness and social isolation, but with some retained capacity to feel involved in the world and to form relationships, distinguishing it from a more complete schizoid detachment
- Fluctuating episodes of feeling detached from the world, including experiences described as depersonalisation, during which the person withdraws further
- Odd or eccentric communication and inappropriate affect during these episodes
- Ideas of reference, odd or unusual beliefs that fall short of true delusion, magical thinking, and suspiciousness
Eliciting it at interview
- Ask about the person's overall sense of connection to others and to the world, and whether this fluctuates over time rather than being uniformly absent
- Explore any experiences of feeling detached or unreal, including depersonalisation, and what tends to bring these episodes on
- Assess unusual beliefs carefully for conviction and fixity, to establish whether they remain ideas the person can, with effort, entertain doubt about, rather than true delusions
- Take a longitudinal history and consider careful follow-up where the picture is unclear, since distinguishing this pattern from a prodromal phase of schizophrenia often cannot be done with confidence at a single assessment
Distinguishing features
- Differs from schizoid personality disorder in retaining some capacity for relationships and some fluctuating sense of involvement with the world, rather than a uniform, stable detachment
- Differs from schizophrenia itself in that odd beliefs remain short of delusion and disorganised communication remains short of a formal thought disorder or true psychosis
- Classified differently across systems: grouped with the personality disorders in DSM-IV and DSM-5, but classified within the schizophrenia section in ICD-10, reflecting differing views of how closely it is bound to that illness
- Overlaps descriptively with depersonalisation during its detached episodes, though schizotypal personality disorder is a broader, longstanding pattern rather than a single phenomenon
Common misconceptions
- That schizotypal personality disorder is simply an early or mild form of schizophrenia; while the association is real and the distinction from a prodrome can be genuinely difficult, the two are not the same thing and many people with this pattern never develop schizophrenia
- That the odd beliefs seen in this disorder are delusions; they characteristically remain short of the fixed, unshakeable conviction that defines true delusion
Related phenomena
Diagnostically relevant to
Schizophrenia (spectrum-related) (links open the DSM-5 Learning Lab)
Practice this
A longstanding pattern of social oddness is described in a patient who has a small number of relationships he does genuinely value, but who experiences fluctuating episodes of feeling detached from the world, holds several odd beliefs that fall short of true delusions, and shows unusual, eccentric ways of communicating with others. What is this? · A patient has shown a consistent, unchanging pattern of complete emotional detachment and social withdrawal since adolescence, with no interest whatsoever in forming relationships, no fluctuating episodes, no odd beliefs, and no unusual communication style. Before revealing the answer: is this schizotypal personality disorder? · A patient shows a longstanding pattern of social withdrawal and detachment. Before revealing the answer, decide what distinguishes schizotypal personality disorder from schizoid personality disorder. · A patient shows a longstanding pattern of social oddness. Before revealing the answer, decide how you would explore whether this is schizotypal personality disorder. · Explain why schizotypal personality disorder is classified differently across major diagnostic systems, and why this reflects a genuine underlying uncertainty rather than a simple labelling difference.
Illustration
A 26-year-old man maintains a handful of long-standing friendships but describes periods, lasting days, when the world feels 'unreal and far away' and he becomes convinced that overheard conversations on the bus contain coded messages about him, a belief he later admits, when pressed, he cannot be fully certain of.
References
- Casey, P. & Kelly, B. (2019). Fish's Clinical Psychopathology, 4th ed. Ch. 10, 'Personality Disorders'.