Adverse events and the relation with quality of life in adults with intellectual disability and challenging behaviour using psychotropic drugs

Highlights

• 84.4% of 103 adults with ID and challenging behaviour had ≥1 adverse event.

• Using ≥1 psychotropic drugs significantly increased the prevalence of adverse events.

• Adverse events were associated with lower quality of life.

• More attention for the impact of adverse events on the quality of life is needed.

Abstract

Background

Psychotropic drugs are prescribed to approximately 30–40% of adults with intellectual disability (ID) and challenging behaviour, despite the limited evidence of effectiveness and the potential of adverse events.

Aims

To assess the prevalence of adverse events in association with psychotropic drug use in adults with ID and challenging behaviour and to examine the relation of these adverse events with the person's quality of life.

Method

The presence of adverse events was measured with a questionnaire that had to be filled in by the physicians of the participants. Movement disorders were measured separately with a standardised protocol. The strength of the association between adverse events and Intellectual Disability Quality of Life-16 (IDQOL-16), and daily functioning was investigated using linear regression analyses, taking into account the severity of disease (CGI-S) as potential confounder.

Results

Virtually all of 103 adults with ID and challenging behaviour had at least one adverse event (84.4%) and almost half had ≥3 adverse events (45.6%) across different subclasses. Using psychotropic drugs increased the prevalence of adverse events significantly. Respectively 13% of the patients without psychotropic drugs and 61% of the patients with ≥2 psychotropic drugs had ≥3 adverse events. Having adverse events had a significantly negative influence on the quality of life.

Conclusions

A large majority of all patients had at least one adverse event associated with psychotropic drug use. More attention is needed for these adverse events and their negative influence on the quality of life of these patients, taking into account the lack of evidence of effectiveness of psychotropic drugs for challenging behaviour.

Introduction

The prevalence of challenging behaviour in adults with intellectual disability (ID) is high: estimates vary from 20% to over 50%, depending on the setting, definition and measurement method (Cooper et al., 2007, Cooper et al., 2009, Crocker et al., 2006, Deb et al., 2001, Singh et al., 1997). In these people psychotropic drugs, especially antipsychotics, are frequently (30–40%) used to treat the challenging behaviour even though there is a lack of evidence of effectiveness and a considerable risk of adverse drug reactions (Brylewski and Duggan, 1999, de Kuijper et al., 2010, Deb and Unwin, 2007, Holden and Gitlesen, 2004, Matson and Mahan, 2010, Matson and Neal, 2009, Scheifes et al., 2011, Tsiouris, 2010, Tsiouris et al., 2013). Most adults with ID treated with antipsychotics use them for many years, sometimes even decades (de Kuijper et al., 2013).

Frequently occurring adverse events of psychotropic drug use are, amongst others, psychological symptoms (e.g., sedation, inner unrest), neurological symptoms (e.g., epileptic seizures, dyskinesia), weight changes, sexual symptoms (e.g., diminished sexual desire, erectile dysfunction) and psychological or physical dependence (Advokat et al., 2000, Deb and Unwin, 2007, Friedlander et al., 2001, Frighi et al., 2011, Mahan et al., 2010, McKee et al., 2005, Roke et al., 2012). These adverse events can be more difficult to detect in adults with ID than those without ID, because impaired communication of the adult with ID hampers the recognition and interpretation of signs and symptoms (Dosen & Day, 2001). Furthermore the adverse event may overlap with the appearance of the psychopathology; for example irritability and agitation may seem a psychiatric or behavioural symptom instead of an adverse event (Charlot et al., 2011, Valdovinos et al., 2005).

Although quality of life is an important aspect of treatment outcome, measurements of quality of life are rarely included in pharmacological intervention studies in adults with ID (Bertelli et al., 2013, Hemmings et al., 2013, Zarcone et al., 2008). Studies on the effect of psychotropic drugs report adverse events as secondary outcomes (Aman et al., 2002, Gagiano et al., 2005, Snyder et al., 2002, Tyrer et al., 2008). A small percentage of published studies systematically address adverse events and risk factors thereof (de Kuijper et al., 2013, Fodstad et al., 2010, Frighi et al., 2011, Mahan et al., 2010). There are no studies on the consequences of adverse events on the quality of life.

The aim of this study was to assess the prevalence of adverse events in association with psychotropic drug use in adults with ID and challenging behaviour and to examine the relation of these adverse events with the person's quality of life.