848
CLINICAL REPORT
Longer Duration of Untreated Psychosis is Associated with Poorer
Outcomes for Patients with Delusional Infestation
Dmitry V. ROMANOV 1,2 , Peter LEPPING 3,4 , Anthony BEWLEY 5 , Markus HUBER 6 , Roland W. FREUDENMANN 7 , Andrey LVOV 8 ,
Stephen Bertel SQUIRE 9 and Eric O. NOORTHOORN 10,11
Department of Psychiatry and Psychosomatics, I.M. Sechenov First Moscow State Medical University, 2 Department of Boundary and
Psychosomatic Disorders, Mental Health Research Center, Moscow, Russia, 3 Betsi Cadwaladr University Health Board North Wales, Centre for
Mental Health and Society Bangor University, UK, 4 Mysore Medical College and Research Institute, Mysore, India, 5 Department of Dermatology,
Barts Health NHS Trust, Royal London Hospital, UK, 6 Department of Psychiatry, General Hospital Bruneck, South Tyrol, Italy, 7 Department
of Psychiatry and Psychotherapy III, University of Ulm, Germany, 8 Department of Clinical Dermatovenerology and Cosmetology, Moscow
Scientific and Practical Center for Dermatovenerology and Cosmetology, Moscow, Russia, 9 Tropical Medicine, Liverpool School of Tropical
Medicine, UK, 10 GGnet Community Mental Health Centre, Warnsveld, and 11 Dutch Information Centre for Coercive Measures, Stichting
Benchmark GGZ, Bilthoven, The Netherlands
1
We examined the association between the duration
of untreated psychosis and outcome for patients with
delusional infestation. This multi-centre international
study included 211 consecutive patients. Illness seve-
rity was evaluated at first presentation and outcome
was measured with the Clinical Global Impression scale
(CGI) at baseline and follow-up. A regression analysis
showed a clear clinical and statistically significant as-
sociation between shorter duration of untreated psy-
chosis and better outcome at follow-up. Patients with
a duration of untreated psychosis of less than one
year showed a CGI-S change from 5.37 to 2.07; those
with a duration of untreated psychosis of 1–5 years a
change from 5.48 to 2.59, and those with a duration
of untreated psychosis of > 5 years a change from 5.59
to 3.37. This difference of 1.1 CGI points between the
groups resembles a clinically relevant difference in pa-
tient outcome. Our results suggest that longer dura-
tion of untreated psychosis in patients with delusional
infestation is associated with significantly less favour
able clinical outcomes.
Key words: delusional infestation; duration of untreated psy-
chosis; early intervention; outcome; clinical relevance; liaison
psychiatry.
Accepted Jan 23, 2018; Epub ahead of print Jan 24, 2018
Acta Derm Venereol 2018; 98: 848–854.
Corr: Dmitry V. Romanov, Professor, Department of Psychiatry and Psy-
chosomatics, I.M. Sechenov First Moscow State Medical University, and
Mental Health Research Center, 127566 1-5-79 Vysokovoltny proezd,
Moscow, Russia. E-mail: [email protected], [email protected]
D
elusional infestation (DI) is a psychiatric disorder
in which patients have the delusional belief that
they are infested with parasites or other living creatures
(worms, fungi etc.), or inanimate pathogens such as fibres,
threads or particles (1). DI is a psychotic disorder distin-
ctly different from schizophrenia, schizoaffective and
brief psychotic disorders. It is categorized as a delusional
disorder, somatic type (297.1 in DSM-5; F22 in ICD-10).
DI patients fail to fulfill criteria for schizophrenia, as they
do not normally show disorganised speech, disorganised
or catatonic behaviour, and negative symptoms such as
blunting of affect, poverty of speech and thought, reduced
doi: 10.2340/00015555-2888
Acta Derm Venereol 2018; 98: 848–854
SIGNIFICANCE
Delusional infestation is a psychiatric disorder in which pa-
tients have the belief that they are infested with parasites
or other living on non-living things undetectable by objec-
tive examination. Duration of untreated psychosis is the
time that passes from manifestation of the first psychotic
symptom to initiation of adequate antipsychotic drug treat-
ment. It has been proven to be an important clinical outco-
me measure in schizophrenia and other psychoses but no
studies exist for delusional infestation. We performed the
first international multicentre study and showed a clear as-
sociation between shorter duration of untreated psychosis
and better outcome in delusional infestation. Our results
suggest that earlier intervention is a desirable option in
delusional infestation, leading to better outcomes.
social drive, loss of motivation, lack of social interest, and
inattention to social or cognitive input. Hallucinations in
DI, if present, are not prominent and related to the delu-
sional theme of the infestation. Apart from the impact
of the delusion(s) or its ramifications, functioning is not
markedly impaired.
The prevalence of DI is estimated between 5.58 and
83.23 cases per 1 million inhabitants (2, 3). Because pa-
tients with DI do not believe that they have a psychiatric
illness, they usually seek referral to dermatologists or
other specialists. Patients may also contact pest control
businesses in order to detect and eradicate the perceived
pathogen (1). Patients’ search for an identifiable infesta-
tion leads them to visit multiple physicians (1). As a result
long duration of untreated psychosis (DUP) may be a
common problem in patients with DI.
DUP is defined as the time that passes from mani-
festation of the first psychotic symptom to initiation of
adequate evidence-based antipsychotic drug treatment (4,
5). Defining the precise onset of psychosis can sometimes
remain approximate as it may depend on patient recall.
Nevertheless, generally, the measurement of DUP has
proven to have good to excellent inter-rater reliability, as
pointed out by Rubio & Correll (6). In their review they
found tha