Behavioral and Psychological Symptoms of Frontotemporal Dementia: A Review

Once thought to be an infrequent cause of dementia, it is now estimated that FTD is found in 4% of the general dementia population,1 and is present in 20% to 30% of dementia patients younger than 65 years.2,3 This early-onset dementia can initially present in a variety of phenotypes, most commonly as a gradual change in behavior, personality and/or language ability.4 Symp toms may worsen to the point of a loss of independence5 and inappropriate social functioning.6 There have been multiple attempts to clearly outline the key diagnostic features of the clinical variants.7-9 Three distinct clinical variants have arisen: the behavioralbased (bv-FTD), and the languagebased primary progressive aphasia (PPA) and semantic dementia (SD). Bv-FTD is defined by an impairment in social functioning and emotional blunting in the patient, but may also include a decline in personal hygiene and mental rigidity, and distractibility.7,9 PPA patients initially present with a progressive loss of speech without cognitive or behavioral impairment, while SD patients’ fluency is intact (though the quality of speech is compromised and behavioral symptoms may be present at the onset of the disease).7,10 Although improvements have been made in the diagnosis of FTD, treatment options remain limited and have focused on the management of neuropsychiatric symptoms. Only a handful of treatment trials in FTD patients have been conducted, using interventions including antidepressants,11-14 antipsychotics15 and cognitive enhancers.16-18 The numerous consensuses have outlined the typical neuropsychiatric symptoms occurring in patients with FTD.7,9 At early onset of the disease, many of the behavioral symptoms are present in the bv-FTD variant, and to a lesser extent in SD and PPA.19,20 The most common neuropsychiatric sym p toms associated with FTD, their neurobiological correlates and the treatment options currently available are outlined below.