Insomnia in neurological disorders: Prevalence, mechanisms, impact and treatment approaches

Insomnia is more prevalent in neurological disorders compared to the general population, with rates ranging from 11 to 74.2% in neurodegenerative disorders, 20 to 37% in vascular diseases, 13.3 to 50% in inflammatory diseases, 28.9 to 74.4% in epilepsy, and nearly 70% in migraines. Insomnia in neurological disorders stems from a variety of factors, encompassing physical and neuropsychiatric factors, behavioral patterns, and disruptions in the biological clock and circadian rhythm. There are bidirectional connections between neurological disorders and insomnia. Insomnia in neurological disorders worsens symptoms, resulting in heightened depressive symptoms, elevated mortality rates, reduced quality of life, and intensified acute symptoms. Managing comorbid sleep disorders, especially in the presence of psychiatric comorbidities, is crucial. Cognitive behavioral therapy for insomnia (CBT-I) is the first-line recommendation for insomnia management in neurological disorders. Other treatments are second-line strategies. Melatonin may demonstrate effectiveness in addressing insomnia, with soporific and chronobiotic effects. Furthermore, it has the potential to alleviate "sundowning" and behavioral disturbances, while generally being well-tolerated. Other treatment options that may be of interest include morning bright light therapy, sedative antidepressants, new orexin dual antagonists and levodopa specifically indicated for Parkinson's disease. Benzodiazepines and z-drugs can be used primarily during acute phases to prevent pharmacotolerance and minimize side effects. However, they should be avoided in patients with neurological disorders and not used in patients over 75 years old due to the risk of falls and confusion. In neurological disorders, insomnia has a profound impact on daytime functioning, making its management crucial. Effective treatment can result in improved outcomes, and additional research is necessary to investigate alternative therapeutic options and enhance patient care.

Validation of a data collection set for the psychiatric, addiction, sleep and chronobiological assessments of patients with depression: A Delphi study for the SoPsy-depression French national cohort

OBJECTIVES

Despite international efforts to identify biomarkers of depression, none has been transferred to clinical practice, neither for diagnosis, evolution, nor therapeutic response. This led us to build a French national cohort (through the clinical and research network named SoPsy within the French biological psychiatry society (AFPBN) and sleep society (SFRMS)), to better identify markers of sleep and biological rhythms and validate more homogeneous subgroups of patients, but also to specify the manifestations and pathogeneses of depressive disorders. Before inclusions, we sought to provide a predefined, standardized, and robust set of data to be collected in all centers.

METHODS

A Delphi process was performed to achieve consensus through the independent rating of invited experts, the SoPsy-depression co-investigators (n=34). The initial set open for vote included 94 questionnaires targeting adult and child psychiatry, sleep and addiction.

RESULTS

Two questionnaire rounds were completed with 94% participation in the first round and 100% participation in the second round. The results of the Delphi survey incorporated the consensus opinion of the 32 members who completed both rounds. Nineteen of the 94 questionnaires achieved consensus at the first round and seventy of 75 at the second round. The five remaining questionnaires were submitted to three experts involved in the steering committee during a dedicated meeting. At the end, 24 questionnaires were retained in the mandatory and 26 in the optional questionnaire set.

CONCLUSIONS

A validated data collection set of questionnaires is now available to assess psychiatry, addiction, sleep and chronobiology dimensions of depressive disorders.

Sleep quality of medical students and relationships with academic performances

OBJECTIVE

Sleep health is a major public health concern because of its correlation with physical and mental health, and it may be particularly altered in medical students. This study aims: i) to examine the sleep characteristics of French medical students and their knowledge about basic sleep hygiene rules and; ii) to examine the correlations between sleep quality and academic performances, as well as between sleep quality and sleep knowledge.

METHODS

Students from 4th, 5th and 6th years of medicine, of the Faculty of Paris Diderot, voluntarily responded to an online questionnaire including PSQI and multiple-choice quizzes (MCQ) about basic sleep hygiene rules.

RESULTS

From the 177 participants, 49.7% had a poor sleep (PSQI>5). Regarding sleep latency, 44.6% needed>30min to fall asleep at least once a week, 26.5% slept 6 hours or less by night, 42.4% of them qualified their sleep quality as bad or very bad. A serious lack of knowledge about basic sleep hygiene rules was observed, with an average score at the MCQ of 6.61/10, and only 31% of medical students were aware of basic good sleep habits. Significant correlations were observed between sleep efficiency and all academic mean scores (both regarding the morning, afternoon, and pooled mean scores), and between sleep disturbances and the morning mean score.

CONCLUSIONS

French medical students have a poor sleep quality, correlating with academic performances, and present a poor knowledge of basic sleep rules. These findings are a call to improve medical training schedules and to develop prevention and training programs.

Use of immediate release melatonin in psychiatry: BMI impacts the daily-dose

OBJECTIVE

There is a growing interest in psychiatry regarding melatonin use both for its soporific and chronobiotic effects. This study aimed to evaluate factors impacting the daily-dose.

METHODS

In a university department of psychiatry in Paris (France), we conducted a posteriori naturalistic observational study from April 03, 2017 to January 31, 2018. We assessed links between sociodemographic and clinical characteristics and daily dose of melatonin (the daily-dose of melatonin initiation and the daily-dose at Hospital discharge). A survey of drug interactions was performed regarding metabolic inducers and inhibitors of the cytochrome P450 1A2.

RESULTS

Forty patients were included and treated with immediate-release melatonin. For patients with no history of melatonin use, the initiation dose of was 2 or 4mg, with no effects of age, weight, BMI, melatonin indication, cause of hospitalization. We found that higher discharge dose was associated with higher BMI (P=0.036) and more reevaluations of melatonin dose (P=0.00019). All patients with a moderate inducer (n=3, here lansoprazole) were significantly more associated with the discontinuation melatonin group (P=0.002).

CONCLUSION

The BMI and the number of reevaluations impact the daily dose of melatonin. Two mechanisms may explain that BMI may need higher doses: (i) melatonin diffuses into the fat mass, (ii) the variant 24E on melatonin receptor MT2, more frequent in obese patients, leads to a decrease of the receptor signal.

[Psychopathological consequences of confinement]

The psychological effects of isolation have already been described in the literature (polar expeditions, submarines, prison). Nevertheless, the scale of confinement implemented during the COVID-19 pandemic is unprecedented. In addition to reviewing the published studies, we need to anticipate the psychological problems that could arise during or at a distance from confinement. We have gone beyond the COVID-19 literature in order to examine the implications of the known consequences of confinement, like boredom, social isolation, stress, or sleep deprivation. Anxiety, post-traumatic stress disorder, depression, suicidal or addictive behaviours, domestic violence are described effects of confinement, but the mechanisms of emergence of these disorders and their interrelationships remain to be studied. For example, what are the mechanisms of emergence of post-traumatic stress disorders in the context of confinement? We also remind the reader of points of vigilance to be kept in mind with regard to eating disorders and hallucinations. Hallucinations are curiously ignored in the literature on confinement, whereas a vast literature links social isolation and hallucinations. Due to the broad psychopathological consequences, we have to look for these various symptoms to manage them. We quickly summarize the diagnostic and therapeutic approaches already in place, such as telemedicine, which is undergoing rapid development during the COVID-19 crisis.

Does childhood experience of attention-deficit hyperactivity disorder symptoms increase sleep/wake cycle disturbances as measured with actigraphy in adult patients with bipolar disorder?

Childhood attention-deficit hyperactivity disorder (ADHD) is a common precursor of adult bipolar disorders (BD). Furthermore, actigraphy studies demonstrate that each disorder may be associated with abnormalities in sleep and activity patterns. This study investigates whether the presence or absence of self-reported childhood experiences of ADHD symptoms is associated with different sleep and activity patterns in adults with BD. A sample of 115 euthymic adult patients with BD was assessed for childhood ADHD symptoms using the Wender Utah Rating Scale (WURS) and then completed 21 days of actigraphy monitoring. Actigraphic measures of sleep quantity and variability and daytime activity were compared between BD groups classified as ADHD+ (n = 24) or ADHD- (n = 91), defined according to established cutoff scores for the WURS; then we examined any associations between sleep-wake cycle parameters and ADHD dimensions (using the continuous score on the WURS). Neither approach revealed any statistically significant associations between actigraphy parameters and childhood ADHD categories or dimensions. We conclude that the sleep and activity patterns of adult patients with BD do not differ according to their self-reported history of ADHD symptoms. We discuss the implications of these findings and suggest how future studies might confirm or refute our findings.

Which actigraphic variables optimally characterize the sleep-wake cycle of individuals with bipolar disorders?

OBJECTIVE

To examine which combination of objectively measured actigraphy parameters best characterizes the sleep-wake cycle of euthymic individuals with bipolar disorder (BD) compared with healthy controls (HC).

METHODS

Sixty-one BD cases and 61 matched HC undertook 21 consecutive days of actigraphy. Groups were compared using discriminant function analyses (DFA) that explored dimensions derived from mean values of sleep parameters (Model 1); variability of sleep parameters (2); daytime activity (3); and combined sleep and activity parameters (4). Exploratory within-group analyses examined characteristics associated with misclassification.

RESULTS

After controlling for depressive symptoms, the combined model (4) correctly classified 75% cases, while the sleep models (1 and 2) correctly classified 87% controls. The area under the curve favored the combined model (0.86). Age was significantly associated with misclassification among HC, while a diagnosis of BD-II was associated with an increased risk of misclassifications of cases.

CONCLUSION

Including sleep variability and activity parameters alongside measures of sleep quantity improves the characterization of cases of euthymic BD and helps distinguish them from HC. If replicated, the findings indicate that traditional approaches to actigraphy (examining mean values for the standard set of sleep parameters) may represent a suboptimal approach to understanding sleep-wake cycles in BD.

Sleep and circadian rhythms as possible trait markers of suicide attempt in bipolar disorders: An actigraphy study

BACKGROUND

The poor prognostic of Bipolar disorders (BD) is closely linked to deaths by suicide. Sleep and circadian abnormalities are observed during all phases of BD and are also associated with suicide attempt (SA). In this context, this study sought to identify specific sleep and circadian rhythms markers associated with suicidal attempt in euthymic patients with BD.

METHODS

The sample (N = 236) comprised 3 groups: 147 patients with BD including 57 with a history of SA and 90 without (NoSA), and 89 healthy controls (HC). All participants were recorded during 21 days with actigraphy.

RESULTS

SA was associated with women gender (p = 0.03), familial history of SA (p = 0.03), mixed episodes (p = 0.001), and benzodiazepines (p = 0.019). SA, compared to noSA, had a morning phase preference (p = 0.04), and were more vigorous on the circadian type inventory (p = 0.04), and tended to suffer more from insomnia (45% versus 25% respectively, p = 0.10). SA was also associated with an earlier onset of daily activity assessed with actigraphy (M10 onset: p = 0.01). Backward stepwise linear regression indicated that a combination of four variables (Gender, vigour, insomnia, M10onset) significantly differentiated patients with SA from NoSA (p = 0.03).

LIMITATIONS

Cross-sectional design, and no examination of suicidal behaviors' subgroups such as first attempters or repeaters, or violent suicide attempt.

CONCLUSIONS

Woman gender, vigorous circadian type, insomnia and an earlier daily activity appeared independently associated with SA in BD. If these biomarkers are confirmed in prospective studies, they should be screened and used to prevent suicide, with the development of personal and targeted chronobiological treatments.

Metabolic syndrome and actigraphy measures of sleep and circadian rhythms in bipolar disorders during remission

OBJECTIVE

This study explored the correlations between sleep and circadian rhythm measures and the metabolic syndrome (MetS) components in remitted patients with bipolar disorder (BD).

METHOD

Euthymic patients with BD (n = 67) were recorded by 3 weeks with actigraphy. We used nonparametric correlations to study the links between the MetS parameters, atherogenic index of plasma (AIP), sleep efficacy, sleep latency, fragmentation index, and phase and amplitude of rhythms. We performed multivariable analyses to take into account potential confounding factors such as sleep apnea risk, antipsychotics use, and smoker status.

RESULTS

We found correlations between lower sleep efficiency and higher triglyceride levels (P = 0.002), lower M10 onset (beginning of the 10 most active hours during the 24-h cycle) and higher systolic blood pressure (P = 0.03), higher fragmentation index and higher systolic blood pressure (P = 0.009), lower sleep efficiency, higher fragmentation index, and higher AIP (respectively P = 0.02 and P = 0.04). These correlations mostly remained significant when adjusting for confounders, with the exception of M10 onset and systolic blood pressure.

CONCLUSION

Sleep efficiency and fragmentation index might contribute to the cardiovascular risk of patients with BD independently of major confounding factors. Although these associations did not imply causality, proposing interventions on sleep quality and circadian rhythm regularity might contribute to reduce cardiovascular risk in patients with BD.

Childhood trauma and mixed episodes are associated with poor response to lithium in bipolar disorders

OBJECTIVES

Reliable predictors of response to lithium are still lacking in bipolar disorders (BDs). However, childhood trauma has been hypothesized to be associated with poor response to lithium.

METHODS

We included 148 patients with BD, euthymic when retrospectively and clinically assessed for response to lithium and childhood trauma using reliable scales.

RESULTS

According to the 'Alda scale', the sample consisted in 20.3% of excellent responders, 49.3% of partial responders and 30.4% of non-responders to lithium. A higher level of physical abuse significantly correlated with a lower level of response to lithium (P = 0.009). As compared to patients not exposed to any abuse, patients with at least two trauma abuses (emotional, physical or sexual) were more at risk of belonging to the non-responders group (OR = 4.91 95% CI (1.01-27.02)). Among investigated clinical variables, lifetime presence of mixed episodes and alcohol misuse were associated with non-response to lithium. Multivariate analyses demonstrated that physical abuse and mixed episodes were independently associated with poor response to lithium (P = 0.005 and P = 0.013 respectively).

CONCLUSIONS

Childhood physical abuse might be involved in a poor future response to lithium prophylaxis, this effect being independent of the association between clinical expression of BD and poor response to lithium.

[Seasons, circadian rhythms, sleep and suicidal behaviors vulnerability]

INTRODUCTION

Suicidal behaviors are common in the general population and are so a major public health problem. In order to improve suicide prevention and to reduce the mortality by suicide, it appears essential to better identify suicide risk factors. Seasonality, circadian rhythms and sleep abnormalities have been already associated with numerous psychiatric disorders. This review aimed to characterize the associations between seasonality, circadian rhythms, sleep and suicidal behaviors including suicide attempts and completed suicides.

METHODS

We conducted a literature search between 1973 and 2015 in PubMed databases using the following terms: ("suicide" OR "suicidality" OR "suicide attempts" OR "suicidal behavior") AND ("circadian rhythms" OR "seasons" OR "sleep").

RESULTS

Many studies confirm a specific seasonality for suicide with a higher peak of suicides in spring for both sex and a lower peak in autumn especially for women. This distribution seems to correlate with depressive symptoms (especially for the autumn peak), gender and different types of suicide. Regarding gender and type of suicide differences, males more commonly commit violent suicide with a higher rate of suicides in spring. Suicide behaviors appear to be influenced by climatic and biological factors like sunshine, daylight cycles, temperature, air pollutants, viruses, parasites and aeroallergens. Circadian variations exist in suicide rates depending on age with a morning peak for elder and an evening peak for youth. In addition, completed suicide peak in early morning whereas suicide attempts peak rather in later afternoon. Several biomarkers dysregulation like melatonin, serotonin and cortisol may be implicated in suicide circadian variations. Furthermore, specific sleep disorders like insomnia, nightmares and sleep deprivation are common risk factors of suicide and possibly independently of the presence of depressive symptoms. Finally, the efficacy of chronotherapeutics (such as luminotherapy, dark therapy, sleep deprivation and melatonin drugs) has been suggested in the reduction of suicidal behaviors.

CONCLUSION

The suicide seasonality is very well documented showing a main peak in spring and another one in autumn. A suicide circadian distribution also exists depending of the suicidal behavior intensity and of the age. Numerous sleep disorders are also suicide risk factors and can be treated with chronotherapeutics. A better identification of seasonality, circadian rhythms and sleep abnormalities in suicidal behaviors could allow a better prevention in suicidal attempts and a reduction in death by suicide.

Course of residual symptoms according to the duration of euthymia in remitted bipolar patients

OBJECTIVE

Although many studies showed the negative impact of residual symptoms on the course of bipolar disorder (BD), there is a need to examine potential differences in residual symptoms according to the duration of euthymia in remitted BD patients.

METHOD

This was a large cross-sectional study of 525 euthymic BD out-patients. A multivariate analysis of covariance was conducted to compare depressive and manic residual symptoms, sleep disturbances and cognitive complaints among three patient groups on the basis of duration of euthymia (A. 6 months to <1 year; B. 1 year to <3 years; C. 3 years to ≤5 years).

RESULTS

A significant difference between the three groups was found in residual symptoms [Pillai's Trace: F(8942) = 4.659, P < 0.001]. Tukey post hoc analysis indicated that patients from Group C presented lower residual depressive symptoms, higher sleep quality and better perceived cognitive performance compared with Group A. Group B also presented better sleep and cognitive outcomes than Group A. In addition, Group C showed the lowest incidence of functional impairment.

CONCLUSION

This study suggests that the intensity of residual symptoms and functional impairment in remitted BD patients is negatively related to the duration of euthymia.

Sleep in patients with remitted bipolar disorders: a meta-analysis of actigraphy studies

OBJECTIVE

Sleep dysregulation is highly prevalent in bipolar disorders (BDs), with previous actigraphic studies demonstrating sleep abnormalities during depressive, manic, and interepisode periods. We undertook a meta-analysis of published actigraphy studies to identify whether any abnormalities in the reported sleep profiles of remitted BD cases differ from controls.

METHOD

A systematic review identified independent studies that were eligible for inclusion in a random effects meta-analysis. Effect sizes for actigraphy parameters were expressed as standardized mean differences (SMD) with 95% confidence intervals (95% CI).

RESULTS

Nine of 248 identified studies met eligibility criteria. Compared with controls (N=210), remitted BD cases (N=202) showed significant differences in SMD for sleep latency (0.51 [0.28-0.73]), sleep duration (0.57 [0.30-0.84]), wake after sleep onset (WASO) (0.28 [0.06-0.50]) and sleep efficiency (-0.38 [-0.70-0.07]). Moderate heterogeneity was identified for sleep duration (I2=44%) and sleep efficiency (I2=44%). Post hoc meta-regression analyses demonstrated that larger SMD for sleep duration were identified for studies with a greater age difference between BD cases and controls (β=0.22; P=0.03) and non-significantly lower levels of residual depressive symptoms in BD cases (β=-0.13; P=0.07).

CONCLUSION

This meta-analysis of sleep in remitted bipolar disorder highlights disturbances in several sleep parameters. Future actigraphy studies should pay attention to age matching and levels of residual depressive symptoms.

[Treatment of manic phases of bipolar disorder: critical synthesis of international guidelines]

INTRODUCTION

Bipolar disorder (BD) is the seventh leading cause of disability per year of life among all diseases in the population aged 15 to 44. It is a group of heterogeneous diseases, with frequent comorbid psychiatric or somatic disorders, variable treatment response and frequent residual symptoms between episodes. The major impairment associated with this disorder is related to the high relapse and recurrence rates, the functional impact of comorbidities and cognitive impairment between episodes. The prognosis of the disease relies on the efficacy of relapse and recurrence prevention interventions. Given the heterogeneity of the disorder, relapse and recurrence prevention needs to develop a personalized care plan from the start of the acute phase. In such a complex situation, guideline-driven algorithms of decision are known to improve overall care of patients with bipolar disorder, compared to standard treatment decisions. Although guidelines do not account for all the situations encountered with patients, this systematic approach contributes to the development of personalized medicine.

METHODS

We present a critical review of recent international recommendations for the management of manic phases. We summarize treatment options that reach consensus (monotherapy and combination therapy) and comment on options that differ across guidelines.

RESULTS

The synthesis of recent international guidelines shows a consensus for the initial treatment for manic phases. For acute and long-term management, the anti-manic drugs proposed are traditional mood stabilizers (lithium or valproate) and atypical antipsychotics (APA - olanzapine, risperidone, aripiprazole and quetiapine). All guidelines indicate stopping antidepressant drugs during manic phases. International guidelines also present with some differences. First, as monotherapy is often non sufficient in clinical practice, combination therapy with a traditional mood stabilizer and an APA are disputed either in first line treatment for severe cases or in second line. Second, mixed episodes treatment is not consensual either and some guidelines propose in first line valproate, carbamazepine and some APA, and advice not to use lithium. On the other hand, some guidelines do not propose specific treatment for mixed episodes and group them with manic episodes management. Duration of treatment is unclear.

CONCLUSION

Guidelines utilization has shown that the systemic use by clinicians of decision algorithms in comparison to "treatment as usual" modality improves the overall care of patients with BD. Future data from cohorts of patients seem necessary to complement the existing data from clinical trials. These cohort studies will help to take into account the different individual profiles of BD and thus may help to propose a more personalized medicine.

[Predicting bipolar disorder: what can we learn from prospective cohort studies?]

INTRODUCTION

Bipolar disorder (BD) is a life course illness; and there is increasing awareness of the many personal, social and economic consequences of the illness in older adults. However, it is important to emphasize that BD usually begins in late adolescence or early adulthood and 75 % cases have a first episode in this age period. This early onset and the associated level of disability mean that BD is the 4th leading cause of global disease burden in adolescents and young adults. Internationally, mental health services are increasingly striving to diagnose and treat BD as early as possible to try to prevent poor outcomes. In addition, researchers are using methods employed previously in psychosis studies as these may help us to recognise the earliest manifestations of BD. If it is possible to identify sub-threshold and 'ultra high risk' syndromes for BD, this might lead to new interventions that could target the prevention of first episodes of mania. One approach to understanding these risk syndromes is to examine prospective community cohort studies and BD offspring studies.

METHODS

This paper reviews prospective cohort studies that identify robust risk factors in early illness onset, which was defined as age at onset of BD between 15-25 years.

RESULTS

We found that although > 50 % of individuals who developed BD had developed a putative BD prodrome prior to 14 years of age, this usually began with non-specific symptoms that overlap with similar presentations for those who later develop psychosis or severe depression. However, there are some features that seem to better identify groups with a BD "at-risk" syndrome. This syndrome is frequently composed of several factors such as mood lability, depressive episodes, prior anxiety, sleep and/or conduct disorders, attention and concentration impairment, altered energy patterns, and a family history of mania and/or depression. The course of these early predictors suggests the precursor syndromes are composed of mini-clusters of symptoms many of which are episodic and change over time. During the early phases of BD, most of the affective disturbances reported were depressive in polarity and started during adolescence, there were few manic or mixed or psychotic episodes with an onset before puberty. The pathogenesis of BD demonstrates a gradual progression from non-specific to more specific symptoms and then to frank BD features.

CONCLUSION

Prospective community and offspring BD cohort studies are approaches that together can help us understand the evolution of BD and allow us to define the developmental pathways. Further, identifying subjects with BD "at-risk" syndrome using a clinical staging model may allow benign interventions to be used as first-line treatment - such as neuroprotective agents like essential fatty acids; second line treatments, with a less benign risk to benefit ratio should be reserved for severe or resistant cases.

[Personality and personality disorders in the elderly: diagnostic, course and management]

OBJECTIVE

Little is known about personality and personality disorders in the elderly. This paper summarizes the literature in these fields.

METHODS

Articles were selected using a Medline and Google Scholar search. The keywords were personality, personality disorder, aging and elderly.

RESULTS

Personality is not fixed and can change across the life-time including in the elderly. Personality disorders are frequent with a prevalence estimated between 10 and 20%. These rates are essentially equivalent to that of younger groups. Clinical presentation of these disorders may change over time. Longitudinal observations generally support that the "immature" personality disorders (cluster B), show improvement over time, while the more "mature" (clusters A and C) are characterized by a more chronic course. Many patients with late onset schizophrenia or delusional disorder have a premorbid cluster A personality. Patients with cluster C personality are also stable, and exposed, like all other personality disorders, to depression. Studies suggest that personality disorders may attenuate, re-emerge or appear de novo according to the cluster and the social context. Diagnosing personality disorders in the elderly is a complex undertaking, largely because of the difficulty encountered in distinguishing functional impairments related to personality from those related to physiological and environmental aspects of aging. Tools for assessing personality disorders exist, but there is no ideal assessment instrument for geriatric personality disorders. Psychiatric history and biographical elements have to be collected accurately. Personality disorders may seriously complicate mental and physical health and quality of life. Indeed, a greater risk of depression, suicide, dementia and social isolation is shown in this population. Different types of caring and treatment exist including psychotherapy and pharmacotherapy. Pharmacological strategies should consider augmentation with psychotherapeutic strategies. Interventions should target the predominant presenting problems. Indeed, personality disordered elderly people are a heterogeneous group with frequent axis I comorbidities. Care should be taken on how to administer pharmacological treatment (risk of noncompliance or abuse), pharmacokinetics, pharmacodynamics and finally interaction with age-specific comorbidities. Psychotherapy has shown its effectiveness notably in the management of depression. In institutions, clinical identification of a personality disorder would inform and advise staff regarding the approach to be adopted, and also avoid negative countertransference, emphasizing the pathological aspect of the subject's personality and his/her suffering.

CONCLUSION

Future research should develop adapted and specific diagnosis tools (dimensional and categorical mixed approach), prevention and caring in the elder population. Those studies would be able to determine the link between normal and pathological personality, mortality, depression and dementia.