Antidepressant medications in dementia: evidence and potential mechanisms of treatment-resistance

Treating Depression in Dementia Patients: A Risk or Remedy-A Narrative Review

BACKGROUND

The diagnosis of depression in dementia patients leads to an increase in the burden of the disease. To treat depression in this patient group, antidepressants are frequently used; however, there is not any proof of their therapeutic effectiveness, and their use may be potentially harmful. This narrative review aims to summarize the existing evidence regarding the role of antidepressants in treating depression in dementia patients.

MAIN TEXT

A search was conducted in the PubMed, Excerpta Medica database (EMBASE), and Cochrane databases for randomized controlled trials and meta-analyses wherein antidepressants were given to dementia sufferers to address depression. Fifteen randomized controlled trials and seven meta-analyses were identified. Most well-designed blinded placebo-controlled trials reported a lack of effectiveness of antidepressants in treating depression in dementia patients. Among the seven metanalyses, two reported good efficacy of Selective serotonin reuptake inhibitors (SSRIs). However, two major Cochrane reviews reported little or no effectiveness and increased side effects of antidepressants in dementia patients.

CONCLUSION

There is robust evidence regarding the lack of efficacy of antidepressants in treating depression in dementia patients. However, further well-designed Randomized controlled trials (RCTs,) using scales with good validity and reliability to diagnose depression in dementia patients, sufficient sample sizes, and detailed adverse effect profiles may help determine the rationale for their use.

Adapted problem adaptation therapy for depression in mild to moderate Alzheimer's disease dementia: A randomized controlled trial

INTRODUCTION

Trials of effectiveness of treatment options for depression in dementia are an important priority.

METHODS

Randomized controlled trial to assess adapted Problem Adaptation Therapy (PATH) for depression in mild/moderate dementia caused by Alzheimer's disease.

RESULTS

Three hundred thirty-six participants with mild or moderate dementia, >7 on Cornell Scale for Depression in Dementia (CSDD), randomized to adapted PATH or treatment as usual. Mean age 77.0 years, 39.0% males, mean Mini-Mental State Examination 21.6, mean CSDD 12.9. For primary outcome (CSDD at 6 months), no statistically significant benefit with adapted PATH on the CSDD (6 months: -0.58; 95% CI -1.71 to 0.54). The CSDD at 3 months showed a small benefit with adapted PATH (-1.38; 95% CI -2.54 to -0.21) as did the EQ-5D (-4.97; 95% CI -9.46 to -0.48).

DISCUSSION

An eight-session course of adapted PATH plus two booster sessions administered within NHS dementia services was not effective treatment for depression in people with mild and moderate dementia. Future studies should examine the effect of more intensive and longer-term therapy.

Depressive symptoms in the entire spectrum of cognitive ageing in Greece: evidence from the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD)

OBJECTIVES

To study (i) the prevalence of mild and moderate-to-severe depressive symptoms in the entire spectrum of cognitive ageing in Greece and (ii) the relationship between these symptoms and demographic and clinical data.

METHODS

The study was based on the randomly selected cohort of the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD). Depressive symptoms were assessed with the 15-item version of the Geriatric Depression Scale. Participants also received a comprehensive neuropsychological assessment, while the clinical diagnoses of dementia and mild cognitive impairment were established according to international diagnostic criteria. Statistical analyses relied on comparison tests and a logistic (proportional odds) ordinal regression model.

RESULTS

Depressive symptoms were detected in 19.5% of the 1936 study participants, while 11.3% of both people with MCI and dementia had moderate-to-severe depressive symptoms. The regression model revealed that older adults with more severe depressive symptoms were more likely female, cognitively impaired, less educated, were treated with psychotropic medication and lived in Attica versus Thessaly.

CONCLUSIONS

Since depressive symptoms were detected in almost one in five older adults, healthcare professionals in Greece should safeguard the timely detection and effective treatment of such symptoms and the post-diagnostic care of older adults with depression.

Understanding depression with amyotrophic lateral sclerosis: a short assessment of facts and perceptions

Depression with an average prevalence of 25-40% is a serious condition in amyotrophic lateral sclerosis (ALS) that can impact quality of life and survival of patients and caregiver burden, yet the underlying neurobiology is poorly understood. Preexisting depression has been associated with a higher risk of developing ALS, while people with ALS have a significantly higher risk of developing depression that can cause multiple complications. Depression may be a prodromal or subclinical symptom prior to motor involvement, although its relations with disease progression and impairment of quality of life are under discussion. Unfortunately, there are no studies existing that explore the pathogenic mechanisms of depression associated with the basic neurodegenerative process, and no specific neuroimaging data or postmortem findings for the combination of ALS and depression are currently available. Experience from other neurodegenerative processes suggests that depressive symptoms in ALS may be the consequence of cortical thinning in prefrontal regions and other cortex areas, disruption of mood-related brain networks, dysfunction of neurotransmitter systems, changing cortisol levels and other, hitherto unknown mechanisms. Treatment of both ALS and depression is a multidisciplinary task, depression generally being treated with a combination of antidepressant medication, physiotherapy, psychological and other interventions, while electroconvulsive therapy and deep brain stimulation might not be indicated in the majority of patients in view of their poor prognosis. Since compared to depression in other neurodegenerative diseases, our knowledge of its molecular basis in ALS is missing, multidisciplinary clinicopathological studies to elucidate the pathomechanism of depression in motor system disorders including ALS are urgently warranted.

Depression in dementia with Lewy bodies: a critical update

Depression with an estimated prevalence of 35% is a frequent manifestation of dementia with Lewy bodies (DLB), having negative effects on cognitive performance and life expectancy, yet the underlying neurobiology is poorly understood and most likely heterogeneous. Depressive symptoms in DLB can occur during the clinical course and, together with apathy, is a common prodromal neuropsychiatric symptom of this neurocognitive disorder in the group of Lewy body synucleinopathies. There are no essential differences in the frequency of depression in DLB and Parkinson disease-dementia (PDD), while its severity is up to twice as high as in Alzheimer disease (AD). Depression in DLB that is frequently underdiagnosed and undertreated, has been related to a variety of pathogenic mechanisms associated with the basic neurodegenerative process, in particular dysfunctions of neurotransmitter systems (decreased monoaminergic/serotonergic, noradrenergic and dopaminergic metabolism), α-synuclein pathology, synaptic zinc dysregulation, proteasome inhibition, gray matter volume loss in prefrontal and temporal areas as well as dysfunction of neuronal circuits with decreased functional connectivity of specific brain networks. Pharmacotherapy should avoid tricyclic antidepressants (anticholinergic adverse effects), second-generation antidepressants being a better choice, while modified electroconvulsive therapy, transcranial magnetic stimulation therapy and deep brain stimulation may be effective for pharmacotherapy-resistant cases. Since compared to depression in other dementias like Alzheimer disease and other parkinsonian syndromes, our knowledge of its molecular basis is limited, and further studies to elucidate the heterogeneous pathogenesis of depression in DLB are warranted.

Potential antidepressant effects of a dietary supplement from Huáng qí and its complex in aged senescence-accelerated mouse prone-8 mice

Healthcare is an emerging industry with significant market potential in the 21st century. Therefore, this study aimed to evaluate the benefits of tube feeding Huáng qí and its complexes for 8 weeks on 3-month-old senescence-accelerated mouse prone-8 (SAMP8) mice, 48 in total, randomly divided into 3 groups including control, Huáng qí extract [820 mg/kg Body weight (BW)/day], and Huáng qí complexes (6.2 mL /kg BW/day), where each group consisted of males (n = 8) and females (n = 8). Behavioral tests (locomotion test and aging score assessment on week 6, the single-trial passive avoidance test on week 7, and the active shuttle avoidance test on week 8) were conducted to evaluate the ability of the mice to learn and remember. In addition, after sacrificing the animals, the blood and organs were measured for antioxidant and aging bioactivities, including malondialdehyde (MDA) content and superoxide dismutase (SOD) activity and catalase activities (CAT), and the effects on promoting aging in SAMP8 mice were investigated. The findings showed that Huáng qí enhanced locomotor performance and had anti-aging effects, with positive effects on health, learning, and memory in SAMP-8 mice (p < 0.05), whether applied as a single agent (820 mg/kg BW/day) or as a complex (6.2 mL/kg BW/day) (p < 0.05). Based on existing strengths, a more compelling platform for clinical validation of human clinical evidence will be established to enhance the development and value-added of astragalus-related products while meeting the diversified needs of the functional food market.

Managing depression in frail older people; too little too late or pathologising loss?

It is testament to the advances of modern medicine that we have a population with more older people than ever before. While we are increasingly adept at managing their physical comorbidities, we have made relatively little progress in addressing the psychological impact of ageing. In this article we consider the prevalence and complex aetiology of depression in older people who often have to deal with profound loss, while simultaneously managing multiple comorbidities. We consider the challenges of diagnosing depression faced by healthcare professionals including access to resources and training, and what differentiates depression from socially appropriate low mood. Finally, we discuss treatment options and the difficulties that clinicians face when they have only limited resources and skills available, but a desire to help. We consider the role for antidepressants, and when not to prescribe, before addressing the challenges of providing talking therapies and social interventions.

Dissociable effects of dopaminergic medications on depression symptom dimensions in Parkinson's disease

Background

Depression in Parkinson's disease (PD) is common, disabling and responds poorly to standard antidepressant medication. Motivational symptoms of depression, such as apathy and anhedonia, are particularly prevalent in depression in PD and predict poor response to antidepressant treatment. Loss of dopaminergic innervation of the striatum is associated with emergence of motivational symptoms in PD, and mood fluctuations correlate with dopamine availability. Accordingly, optimising dopaminergic treatment for PD can improve depressive symptoms, and dopamine agonists have shown promising effects in improving apathy. However, the differential effect of antiparkinsonian medication on symptom dimensions of depression is not known.

Aims

We hypothesised that there would be dissociable effects of dopaminergic medications on different depression symptom dimensions. We predicted that dopaminergic medication would specifically improve motivational symptoms, but not other symptoms, of depression. We also hypothesised that antidepressant effects of dopaminergic medications with mechanisms of action reliant on pre-synaptic dopamine neuron integrity would attenuate as pre-synaptic dopaminergic neurodegeneration progresses.

Methods

We analysed data from a longitudinal study of 412 newly diagnosed PD patients followed over five years in the Parkinson's Progression Markers Initiative cohort. Medication state for individual classes of Parkinson's medications was recorded annually. Previously validated "motivation" and "depression" dimensions were derived from the 15-item geriatric depression scale. Dopaminergic neurodegeneration was measured using repeated striatal dopamine transporter (DAT) imaging.

Results

Linear mixed-effects modelling was performed across all simultaneously acquired data points. Dopamine agonist use was associated with relatively fewer motivation symptoms as time progressed (interaction: β=-0.07, 95%CI [-0.13,-0.01], p=0.015) but had no effect on the depression symptom dimension (p=0.6). In contrast, monoamine oxidase-B (MAO-B) inhibitor use was associated with relatively fewer depression symptoms across all years (β=-0.41, 95%CI [-0.81,-0.01], p=0.047). No associations were observed between either depression or motivation symptoms and levodopa or amantadine use. There was a significant interaction between striatal DAT binding and MAO-B inhibitor use on motivation symptoms: MAO-B inhibitor use was associated with lower motivation symptoms in patients with higher striatal DAT binding (interaction: β=-0.24, 95%CI [-0.43, -0.05], p=0.012). No other medication effects were moderated by striatal DAT binding measures.

Conclusions

We identified dissociable associations between dopaminergic medications and different dimensions of depression in PD. Dopamine agonists may be effective for treatment of motivational symptoms of depression. In contrast, MAO-B inhibitors may improve both depressive and motivation symptoms, albeit the latter effect appears to be attenuated in patients with more severe striatal dopaminergic neurodegeneration, which may be a consequence of dependence on pre-synaptic dopaminergic neuron integrity.