Misdiagnoses can have profound implications on treatment outcome; in children also risks of continuation in adulthood, including forensic repercussions.The Conners questionnaire, an international tool to rule in ADHD poses like any structured assessment tool a ceiling effect of optimum sensitivity/specificity. This gap in certainty of diagnosis can be bridged by clinical astuteness on applicable differential diagnoses, an exercise which resulted in transformational treatments in complex ‘ADHD’. This instigated an analysis of the Conners parent questionnaire in relation to common differential diagnoses or problems.

To explore alternative explanations and differential diagnoses in the abbreviated Parent - Conners questionnaire.

To establish common ADHD differential explanations and diagnoses from this questionnaire to inform on more comprehensive diagnostic schedules and algorithms.

Every item of the questionnaire is appraised in relation to its assigned index i.e. ‘oppositional, cognitive problems/inattention, hyperactivity’ and ‘ADHD’. Differential explanations of ADHD symptoms are explored in terms of diagnoses or specific significant impairment according to established psychiatric diagnostic and neurocognitive criteria.

Hyperarousal i.e. anxiety symptoms i.e. correlate with all indices of the questionnaire. The oppositional index can be indicative of anger or social and communication problems. Hyperactivity can also be explained by sensory processing difficulties. The Cognitive/inattention index may reflect (specific) learning difficulties. The ADHD index can reflect learning and communication problems.

Above named alternative explanations for an ADHD diagnosis using the Conners questionnaire need to be further studied to inform on enhanced clinically effective medication and non-medication interventions.