# 15 - 8A05.02 Chronic phonic tic disorder # 8A05.02 Chronic phonic tic disorder 157 Neurodevelopmental disorders Boundary with obsessive-compulsive disorder Repetitive, recurrent movements or vocalizations can also be symptomatic of obsessive-compulsive disorder. Tics can be differentiated from obsessive-compulsive disorder because they appear unintentional in nature and clearly utilize a discrete muscle group. However, it can be difficult to distinguish between complex tics and compulsions associated with obsessive-compulsive disorder. Although tics (both complex and simple) are preceded by premonitory sensory urges, which may diminish over time, tics are not aimed at neutralizing antecedent cognitions (e.g. obsessions) or reducing physiological arousal (e.g. anxiety). Many individuals exhibit symptoms of both obsessivecompulsive disorder and Tourette syndrome, and both diagnoses may be assigned if the diagnostic requirements for each are met. Boundary with self-injurious and self-mutilating behaviours With enough force and repetition, motor tics may lead to self-injury. However, unlike self-injurious and self-mutilating behaviour, Tourette syndrome is not associated with an intention to cause self-injury. Chronic motor tic disorder Essential (required) features • The persistent presence of motor tics is required for diagnosis. • Motor tics are defined as sudden, rapid, non-rhythmic and recurrent movements. • Motor tics have been present for at least 1 year, with onset during the developmental period. Note: other CDDR elements for chronic motor tic disorder are provided below, following the essential features for chronic phonic tic disorder. Chronic phonic tic disorder Essential (required) features • The persistent presence of phonic tics is required for diagnosis. • Phonic tics are defined as sudden, rapid, non-rhythmic and recurrent vocalizations. • Phonic tics have been present for at least 1 year, with onset during the developmental period. 8A05.01 8A05.02 Neurodevelopmental disorders | Secondary-parented categories in neurodevelopmental disorders Clinical Descriptions and Diagnostic Requirements for ICD-11 Mental, Behavioural or Neurodevelopmental Disorders Additional clinical features for chronic motor tic disorder and chronic phonic tic disorder • Motor and phonic tics may be voluntarily suppressed for short periods of time, may be exacerbated by stress, and may diminish during sleep or during periods of focused enjoyable activity. • Tics are often highly suggestible – for example, when an individual with chronic motor tic disorder or chronic phonic tic disorder is asked about specific symptoms, old tics that have been absent for some time may transiently reappear. Boundary with normality (threshold) for chronic motor tic disorder and chronic phonic tic disorder • Transient motor or phonic tics (e.g. eye blinking, throat clearing) are common during childhood, and are differentiated from chronic motor tic disorder and chronic phonic tic disorder by their transient nature. Developmental presentations for chronic motor tic disorder and chronic phonic tic disorder • The prevalence of chronic motor tic disorder is estimated at between 0.3% and 0.8% of school-aged children. • Less is known about the prevalence of chronic phonic tic disorder. Culture-related features for chronic motor tic disorder and chronic phonic tic disorder • If vocalizations or movements have a specific function or meaning in the context of an individual’s culture and are used in ways that are consistent with that cultural function or meaning, they should not be considered evidence of chronic motor tic disorder or chronic phonic tic disorder. Neurodevelopmental disorders | Secondary-parented categories in neurodevelopmental disorders 159 Neurodevelopmental disorders Sex- and/or gender-related features for chronic motor tic disorder and chronic phonic tic disorder • Women with persistent tic disorders may be more likely to experience co-occurring anxiety and fear-related disorders and depressive disorders. Boundaries with other disorders and conditions (differential diagnosis) for chronic motor tic disorder and chronic phonic tic disorder Boundary with autism spectrum disorder and stereotyped movement disorder Repetitive and stereotyped motor movements such as whole-body movements (e.g. rocking) and unusual hand or finger movements can be a characteristic feature of autism spectrum disorder and of stereotyped movement disorder. These behaviours can appear similar to tics but are differentiated because they tend to be more stereotyped, last longer than the duration of a typical tic, tend to emerge at a younger age, are not characterized by premonitory sensory urges, are often experienced by the individual as soothing or rewarding, and can generally be interrupted with distraction. Boundary with obsessive-compulsive disorder Repetitive, recurrent movements or vocalizations can also be symptomatic of obsessive-compulsive disorder. Tics can be differentiated from obsessive-compulsive disorder because they appear unintentional in nature and clearly utilize a discrete muscle group. However, it can be difficult to distinguish between complex tics and compulsions associated with obsessive-compulsive disorder. Although tics (both complex and simple) are preceded by premonitory sensory urges, which may diminish over time, tics are not aimed at neutralizing antecedent cognitions (e.g. obsessions) or reducing physiological arousal (e.g. anxiety). Many individuals exhibit symptoms of both obsessivecompulsive disorder and chronic motor tic disorder or chronic phonic tic disorder, and both diagnoses may be assigned if the diagnostic requirements for each are met. Boundary with self-injurious and self-mutilating behaviours With enough force and repetition, motor tics may lead to self-injury. However, unlike self-injurious and self-mutilating behaviour, chronic motor tic disorder is not associated with an intention to cause self-injury. Neurodevelopmental disorders | Secondary-parented categories in neurodevelopmental disorders Clinical Descriptions and Diagnostic Requirements for ICD-11 Mental, Behavioural or Neurodevelopmental Disorders