Psychosocial treatment of major depression in people with intellectual disabilities. Improvements within the last four decades: points of view

Abstract

Psychosocial treatments like psychotherapy and group therapy are common for the treatment of depression in the general population. Depression in people with intellectual disability presents challenges, because people with intellectual disability often cannot consent to various treatments, clinicians and family members must be involved and use their best judgment. A selected review was conducted to highlight the progress in psychosocial treatment of depression within the last four decades. The main search terms were intellectual disability (ID), depression, and treatment. Nine articles were chosen; and included cognitive behaviour therapy (CBT), computer-assisted CBT, mindfulness-based cognitive therapy (MBCT), exercise therapy, behaviour activation, self-help intervention, dialectal behaviour therapy (DBT), and psychodynamic/psychoanalytical therapy. There were no articles on mental health nursing. Adaptions included smaller groups (in group intervention), visual material, simplifying of concepts, longer duration/more sessions, more practical help, more repetitions when learning new skills, more guiding, professional caregiver/family involvement, and individual support within group interventions.

Keywords:

• intellectual disability; depression; psychosocial treatment

Depression impacts cognition, emotions, physiological processes, and behavior. The core symptoms include depressed mood, loss of joy and interests, decreased cognition, loss of energy, and irritability (APA 2013). The symptoms vary across persons and lifespan, as depression can remit and relapse. Depression is one of the most prevalent mental disorders in the general population (Herrman et al. 2019). Understanding of depression has increased during the last decades, acknowledging both negative life events such as childhood neglect, trauma, bereavement, and genetic and biological predictors as risk factors (Herrman et al. 2019).

Depression is often co-morbid with other mental disorders, especially anxiety disorders (APA 2013), or depressive symptoms occur in the clinical picture of major mental disorders such as disorders in the schizophrenia spectrum, or playing a main part in bipolar disorders (APA 2013). Depressed mood occurs frequently in posttraumatic stress disorder, personality disorders, eating disorders and other mental health problems as well.

The complexity of mental illness calls for diverse treatment options, which during the last three to four decades have come to include a number of treatments. Treatment options today include a variety of biological interventions such as medication, light therapy and electro-convulsive therapy (ECT), and a wide range of psychosocial interventions such as cognitive behavior therapies, psychodynamic therapies, and adjuvant treatments such as behavioral activation, physical exercise or systematic gardening. The development of diverse methods allows more person-centred treatment of depression. For people in the general population, single modality therapy with either medication or psychotherapy is recommended for mild or acute depression (Craighead and Dunlop 2014), while combination therapy is recommended for recurring episodes, chronic depression or severe depression (Craighead and Dunlop 2014).

People with intellectual disability (ID) seem to have increased risk of developing depression compared to the general population according to studies of prevalence (Hermans et al. 2013). People with both ID and autism spectrum disorders seem to have even higher risk than those with ‘ID only’ (Bakken et al. 2016, 2010). However, a recent study examining incidence (new cases or relapses) of depression in ID, found that the incidence among people with ID was similar to those without ID (Cooper, Smiley, Allan and Morrison 2018), suggesting that the high prevalence rates indicates that depression in ID is more enduring and perhaps undertreated (Cooper et al. 2018). This applies especially because longer duration of untreated depression may impact the patient’s outcomes negatively (Ghio et al. 2015). Another factor, which previously has not received proper attention, is the risk of suicide or suicidal behavior in ID (Chaplin, Underwood and McCarthy 2014).

Another challenge is case identification. People with ID may mask their symptoms, and hence symptoms may appear in atypical ways (Langlois and Martin 2008, Hurley 2008). Especially challenging behavior such as aggression, self-injury and screaming has been described as ‘depressive equivalents’ (Sovner and Hurley 1983). However, these symptoms are not specific to depression, and hence core symptoms such as loss of interest in favorite activities and decreased energy (symptoms that also are possible to observe) must be present to complete a diagnosis of depression in people with ID who speak sparsely or do not master reporting on problematic feelings (Hurley 2008).

Treatment of depression in ID has drawn more attention during the last three to four decades. Since Robert Sovner and Anne Hurley’s ground-breaking paper, Do the Mentally Retarded Suffer from Affective Illness? (1983) stated that people with ID suffer from depression in line with other people, generations of new researchers and clinicians have added to the body of knowledge about mental illness in ID generally, and about mood disorder and depression specifically.

Research from the four last decades emphasizes adjustments of treatment methods for mental illness developed for the general population, when treating people with ID (Iversen et al. 2019, Bakken et al. 2016). Sovner and Hurley’s first work together was in a facility for adults with intellectual disability. Their aims, in addition to medication and behavioral support plans, were to ensure that the users had happy lives with social events, outings, family connections, and going on a vacation, for example. Enriching their lives lessens boredom and loneliness (Sovner and Hurley 1983).

In this point of view, the authors wish to highlight especially psychosocial treatment options for people with ID who develop depression, emphasizing the adjustments needed to optimize the treatment outcomes. Consequently, we wanted to answer the following questions: 1. What kind of psychosocial interventions may elicit positive outcomes for people with ID and depression? and 2. What are the main adaptions needed to make the interventions feasible for people with ID?

In order to have a more comprehensive point of view about adjustments to depression in ID, both a systematic search and a manual search was conducted. The manual search included relevant websites for organizations and advisory units. The systematic search included the terms Intellectual disability/mental retardation/learning disability, depression/mood disorder/affective disorder, treatment, and adults. The following databases were used to search for articles published from 1980 through 2021: MEDLINE (PubMed), PsycINFO, and CINAHL. Inclusion criteria were 1. being a clinical paper or a review, 2. encompassing adults, 3. encompassing individuals with ID, 4. encompassing depression, 5. English language. Exclusion criteria were 1. The article encompassing multiple diagnoses additional to depression, 2. Co-morbid anxiety was not an exclusion criterion, as anxiety is frequently co-morbid with depression.

As this point of view aims to get a picture of potentially effective treatments, and useful adaptions, inclusion of potentially interesting papers followed a qualitative approach. I.e. when a certain treatment modality was considered as adequately highlighted, no more papers on this treatment were included. This was particularly applied to articles on CBT, which largely outnumbered other treatment options. The search resulted in 513 potentially relevant papers, which were screened through titles and abstracts. Most of these articles were excluded because treatment was only briefly mentioned. Of the 513 papers, 31 were read in full text. Nine articles were chosen from these 31 to represent improvements in depression treatment of ID. Nine articles were found to represent the treatment options of interest.

A book chapter and eight articles are presented in Table 1. The articles encompassed cognitive behavior therapy (CBT), computer-assisted CBT, mindfulness-based cognitive therapy (MBCT), exercise therapy, behavior activation, self-help intervention, dialectal behavior therapy (DBT), and psychodynamic/psychoanalytical therapy. There were no articles on mental health nursing.

Table 1. Overview of included papers.

First author, year	Design Publication type	Participants, N and characteristics	Intervention	Results	Adaptions
Cooney, 2018	Treatment arm of a RCT Article	24 adults mild/moderate ID	Computer-assisted cognitive behavioral therapy (CBT)	Participants rated the intervention as enjoyable and helpful. Increased awareness of thoughts and feelings.	Simplifying language, using visual material such as Boardmaker picture communication symbols
Hamers, 2018	Review of Non-pharmacological interventions Article	15 articles met inclusion criteria 5 types of non-pharmacological interventions included	CBT, behavioral therapy, exercise, social problem-solving, and bright light therapy	Only a few good studies. CBT most promising in decreasing depressive symptoms. RCTs are needed.	Adaptions not mentioned.
Idusohan-Moizer, 2015	Evaluation of group intervention Article	Two groups (9 + nine participants), adults Borderline or mild ID	Mindfulness-based cognitive therapy (MBCT). Breathing meditations.	Participants reported positive impact on depressive and anxiety symptoms; maintained after 6 weeks	Simplifying. More practical and guided meditations.
Kemp, 2020	Review of treatment evidence Book chapter	Not presented	CBT, Interpersonal psychotherapy, exercise therapy, behavioral activation, psychopharmacological treatments	Both psychosocial and medication proved efficacy over no treatment or waiting list. CBT has the best evidence among psychosocial treatment.	Mild ID: minor adaptions. Moderate ID: repetitions of training new skills, more sessions, simplifications, more guiding, caregiver/ family involvement.
Knight, 2019	Comparing two interventions Article	24 adults mild/moderate ID	Comparing behavioral activation and guided self-help intervention	Patients in both groups largely positive. However, they wanted longer-term help; emphasizing positive relationships with therapists.
McCabe, 2006	Comparison of CBT and controls Article	34 adult participants with mild/ moderate ID, 15 in a control group	5 weeks group intervention with 2 h. sessions.	Participants in the CBT group improved depressive symptoms compared to controls	Small groups, adapted written material (handouts)
McGillivray, 2008	Comparison of CBT and controls Article	47 adults mild ID 13 vocational service staff members. 27 mild ID controls	Staff-administered CBT Staff was trained in advance in ‘Think happy, feel happy, be happy’	Participants in the CBT group improved depressive symptom scores compared to controls	Small groups, adapted written material
Morrissey and Ingamells, 2011	Evaluation of adapted DBT (dialectical behavior therapy Article	25 patients ID (level not mentioned) 5 patients waiting list = control group	DBT with adapted group skills training + weekly individual therapy	Promising results. The participants were more likely than waitlist control to move to lower security facilities.	Simplification of concepts, fewer skills to train, small groups, individual support
Shepherd and Beail, 2017	Systematic review of effectiveness of psychotherapy Article	13 articles included	Including psychoanalytic and psychodynamic psychotherapy	Generally poor quality of research compared to CBT, but positive outcomes is indicated	Adaptions not particularly mentioned

A book chapter and two articles were reviews. The other publications were empirical studies. Almost exclusively, the patients included had borderline, mild or moderate ID. The reviews concluded that CBT had the best evidence base for outcomes from depression treatment in adults with ID. The studies included different designs; RCT (randomized controlled trial), case-control design, comparisons between two different interventions, and before and after design.

The adaptions included smaller groups (in group intervention), visual material, simplifying of concepts, longer duration/more sessions, more practical help, more repetitions when learning new skills, more guiding, professional caregiver/family involvement, and individual support within group interventions.

One study used self-reported patient outcome. The participants emphasized relationships with therapist as the most important outcome (Knight et al. 2019).

The nine included publications reflect the advances in depression treatment for people with ID, compared to only 30 − 40 years ago. There is probably not a single clinician in mental health services, who in 2021 will claim that people with ID do not have the sufficient emotional and cognitive maturity to develop mental illness (Matson and Peters 2020).

Even though CBT has gained most evidence through research, it may not be the right treatment for all people with ID and depression. It is an overall problem that treatments adapted from general mental health services mostly suit people with mild or moderate ID, and not those with severe or profound ID. Furthermore, people with mild to moderate ID and additional conditions such as autism spectrum disorder may have difficulties with almost all treatments mentioned above, especially caused by a lack of ability for introspection and mentalization (Robinson et al. 2017), which may complicate both reporting of symptoms and difficulties, and understanding manualized treatment. Other treatments may, adjuvant to medication or stand-alone, be helpful for people with more severe ID and depression. For example, systematic gardening (Soga et al. 2017), animal-assisted therapy (Ambrosi et al. 2019), exercise therapy (briefly mentioned in Kemp et al. 2020), and sensory therapy (Champagne 2011) have not been studied yet in people with ID. Sensory therapy, such as using weighted blankets, is found to be effective on stress and poor sleep, which is common in depression (Andersen et al. 2017, Champagne et al. 2015). The treatments mentioned above do not need to be adapted, because they require only a minimum level of cognitive abilities.

The close relationship between individual therapist and mental health nursing staff is well known in clinical settings of mental health services for people with ID (Iversen et al. 2019). However, this topic is only briefly mentioned in papers on treatment of mental illness in ID generally, usually stating that close co-operation between professional caregivers and family members is needed when the treatment includes task solving between sessions, like training on new skills. A clinical project on psychotherapy in ID (Bakken in press), has a chapter on co-operation between mental health nurses and individual therapists within therapeutic processes. Interviews with therapists (both individual therapists and mental health nurses) emphasize the necessity of the patient being accompanied at therapy sessions by a nurse or a family member, in order to take charge of the therapeutic processes between sessions (Bakken in press).

Articles on mental health nursing for people with co-morbid ID and depression gave no results in the present search, and this area is generally sparsely studied related to mental health services in ID (Bakken and Sageng 2016). However, a new study, which investigated patients’ experiences with mental health nursing in a specialized psychiatric inpatients unit for ID, found that the patients were mostly concerned about patient-therapist relationships when they were inpatients (Sommerstad et al. in press). This is in line with the findings of Knight and colleagues (2019). The Knight article was the only one in this review that used self-rating on patient outcome from depression treatment. This might be a co-incidence, or maybe not. There is still a need for the development of assessment and treatments of depression, to include people with ID in both decision-making of preferred treatment options, and related to reporting on outcomes. In the future, there is a particular need for treatment options for people with severe or profound ID. Adjuvant treatments to medication used in the general population, such as systematic gardening, behavior activation, exercise therapy, animal assisted therapy, and sensory therapy, may be more thoroughly investigated for people with ID.

There are several weaknesses of this point of view article. The review was conducted in order to highlight the improvements during the ‘pioneering decades’ of developing services for people with ID and additional mental health issues. Not all relevant studies were included. Additionally, we did not search especially for studies published separately in the four actual decades, and we did not include national guidelines from for example the UK. We did not conduct quality ratings. A strength is the searching of multiple databases.

As clinicians and researchers combined, the two authors of this point of view article have seen improvements in the mental health services for people with ID from two different continents, and from the 1980s and the 1990s, respectively, and up until today. We chose depression as an example as depression is common in people with ID and we hope that the future will bring better services to people with ID also in other parts of the world and that health workers in general mental health services especially, will give more attention to their patients with ID. Hopefully, these patients will be included as partners in both assessment and treatment.

The main improvements since the 1980s and until today are:

• Depression (and other mental disorders), is recognized to occur in people with ID

• There is a growing awareness among clinicians that depression is the same disorder in people with ID, and that they will benefit from the same treatment as people in the general population.

• There has been a growing evidence base for psychosocial treatment options since the 1980’s. However, to prove evidence from promising treatments, more RCT research is needed.

Disclosure statement

No potential conflict of interest was reported by the author.