Personality disorder – is polypharmacy the way forward?
The Royal College of Psychiatrists define personality disorder (PD) as a heterogeneous group of conditions which vary greatly in their severity. It is characterised by long-standing, pervasive patterns of thinking, feeling and relating to others that lead to social problems and poor mental health. Problems with inter-personal relationships are a defining feature.
Psychiatric co-morbidity is a common feature of personality disorders particularly depression, anxiety, psychosis and associated substance misuse. However the condition is not a psychiatric disorder itself.
There are associated challenging behaviours which can manifest in violence, aggression and self-harm and these present a huge challenge for the multidisciplinary team to manage.
Personality disorders are classified in three categories:
- Cluster A – ‘Odd and Eccentric’: This includes paranoid, schizoid or schizotypal features, which has been related with schizophrenia later in life
- Cluster B – ‘Dramatic, Emotional and Erratic’: antisocial, borderline or emotionally unstable – EUPD, which is the most common type in mental health services, histrionic or narcissistic
- Cluster C – ‘Anxious’: obsessive-compulsive, avoidant, anxious or dependent
PD normally appears during adolescence or early in adulthood and it is believed to affect 1 in 20 people in the UK at any given time in their lives. It accounts for up to 7.5% of admissions in mental health hospitals. The prognosis is normally good, with most people not meeting the criteria for diagnosis after five years, but a minority of patients will present with PD symptoms until late in life.
PD normally appears during adolescence or early in adulthood and it is believed to affect 1 in 20 people in the UK at any given time in their lives.
The aetiology of PD is not fully understood. A higher prevalence of PD is observed amongst patients whose history features abuse or trauma during childhood, brain problems or early misbehaviour. Literature suggests there to be a heritable component or genetic predisposition.
Trigger factors are wide ranging and could include: substance misuse; anxiety; depression; family, social, financial problems; stressful situations; important events or loss.
The NICE guidance [CG78] Borderline Personality Disorder makes no specific treatment recommendations regarding medication, apart from using sedative antihistamines for manifestation of certain PD symptoms during crises. There is a lack of evidence for using medication to treat PD and no medication is licensed for its treatment, but NICE recommends treating the co-morbidities.
As a complicating factor, PD patients will often actively seek pharmacological treatment which may lead to unjustified long-term ‘prophylaxis’ to prevent further crisis with little rationale. When a new crisis occurs, a second drug is likely to be added. Adherence is often poor for patients with PD and the frequent drug changes make it really difficult to assess if any of the medication provides benefit.
Medication for treating symptoms and psychiatric co-morbidities:
- Antidepressants: SSRIs can improve depressive symptoms and anxiety present in PD. Careful dose titration is needed to avoid agitation. Tricyclics are not recommended due to lack of efficacy and risk of overdose.
- Antipsychotics (normally in low doses): aripiprazole, asenapine, olanzapine, paliperidone, risperidone or quetiapine may help with many symptoms of PD, especially with cluster A or borderline personality disorder. Clozapine (25–100mg daily) may significantly reduce aggressive incidents, especially in the first six months, and significantly reduces admissions, bed days and self-harm.
- Mood stabilisers: lamotrigine, topiramate or valproate have helped to control anger and impulsiveness.
- Sedatives, like promethazine: generally to treat crisis and ideally not to be given for longer than a week. Benzodiazepines (especially short-acting ones) are less preferred as they may cause disinhibition in PD patients and have the potential of abuse.
A Cochrane review in 2010 for borderline personality disorder concluded that there were some beneficial effects with second-generation antipsychotics and mood stabilisers. However, the risk-benefit ratio for most psychotropics – all of which have a propensity to cause significant side effects, is considered unfavourable when used ‘off-label’ to treat personality disorder, and so a time limit for review is recommended when treating symptoms to minimise unnecessary long-term drug therapy.
Psychological therapies have a key role in the treatment of personality disorder, particularly for cluster B type, and these include: MBT, DBT, CBT, schema focussed therapy and transference focussed therapy. Therapy may be required for a number of years to treat PD. Support from friends or families is also key to improving PD outcomes as well as patient involvement, engagement and motivation.
In summary, medication may only help to control some of the symptoms of PD or treat psychiatric co-morbidities. Therefore, polypharmacy should ideally be avoided in this group of patients. More importance should be given to psychological and psychosocial therapies.
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