Bipolar disorder in patients with mental retardation. Mental retardation is a frequent disorder that affects about 2% of the population, with a slight male predominance in mild mental retardation. It can be related to multiple aetiologies and leads to a handicap that is all the more severe as mental impairment is severe. Psychiatric disorders are generally more frequent in people with mental retardation than in the general population with heterogeneous figures. Thus, according to prevalence studies of psychiatric disorders in
this population, the figures range from 10 to 60% when behavioral disorders are taken into account. On the other hand, the prevalence of bipolar disorder in intellectually disabled patients appears to be approximately the same as in the general population, ie 1 to 2%. Bipolar disorders are difficult to diagnose in patients with mental retardation due to: the usual tendency to attribute any symptoms to mental retardation itself; This phenomenon is called “diagnostic overshadowing”; a poorer semiological approach in relation to limited language skills in patients with intellectual disabilities; 3) a presentation of the manic state and the depressive episode somewhat different in the patient with intellectual disability (and this more so as mental retardation is more serious) with, as we find For the three clinical cases studied: for the manic state, a tendency to aggressiveness, provocative, impulsive behavior, experienced as manipulative by the environment, or linked to a search for attention, in addition to the classic symptoms found During manic episodes in the general population; And for the depressed state, behaviors related to irritability, anger, self or heteroaggressive behavior and withdrawal frequently found in addition to the classic symptoms of depression. Given these semiological characteristics, different scales for the assessment of the psychiatric comorbidity of mental retardation have been proposed, but none are currently widely used. Finally, in therapeutic management, some studies show that 30 to 50% of patients with mental retardation receive psychotropic treatment and that neuroleptics are the most commonly used therapies.