Co-existence of disorders--including attention-deficit/hyperactivity disorder, oppositional defiant disorder, tic disorder, developmental coordination disorder, and autism spectrum disorder--and sharing of symptoms across disorders (sometimes referred to as comorbidity) is the rule rather than the exception in child psychiatry and developmental medicine. The acronym ESSENCE refers to Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations. It is a term I have coined to refer to the reality of children (and their parents) presenting in clinical settings with impairing child symptoms before age 3 (-5) years in the fields of (a) general development, (b) communication and language, (c) social inter-relatedness, (d) motor coordination, (e) attention, (f) activity, (g) behaviour, (h) mood, and/or (i) sleep. Children with major difficulties in one or more (usually several) of these fields, will be referred to and seen by health visitors, nurses, social workers, education specialists, pediatricians, GPs, speech and language therapists, child neurologists, child psychiatrists, psychologists, neurophysiologists, dentists, clinical geneticists, occupational therapists and physiotherapists, but, usually they will be seen only by one of these specialists, when they would have needed the input of two or more of the experts referred to. Major problems in at least one ESSENCE domain before age 5 years often signals major problems in the same or overlapping domains years later. There is no time to wait; something needs to be done, and that something is unlikely to be just in the area of speech and language, just in the area of autism or just in special education. (Contains 2 tables.)