Affective Symptoms in Adolescents with Autism: Differentiating the Correlates of Anxiety, Depression and Irritability

Background:  People with autism are known to be at increased risk for a range of mental health problems and also have increased rates of ‘challenging behaviour,’ in which there is severe defiance and aggression towards self and others.  However, the relationship between these two elements is poorly understood and, in particular, the affective components that may play a role in challenging behaviour in autism are not well-characterized.

Objectives:  To explore the role of different mental health problems, most especially affective symptoms, in severe behavioural disturbance or challenging behaviour in autism; To explore whether there is an additional and specific role for neurocognitive  characteristics often seen in autism (such as emotion recognition, theory of mind) in influencing challenging behaviour.

Methods:  This study uses data from the Special Needs and Autism Project (SNAP), a longitudinal, population-based cohort of 100 adolescents with ASD assessed at both 12 and 16 years. A measure of severe mood problems (SMP) was previously developed from the Profile of Neuropsychiatric Symptoms (PONS) and included: low mood, depressive thoughts, labile mood and explosive rage.  Symptoms of anxiety, irritability and oppositionality were further added as potential contributors to challenging behaviour.  Autism severity was measured with the Social Responsiveness Scale (SRS) and autism diagnostic classification was childhood autism/any other PDD. IQ was measured on the Wechsler Abbreviated Scale of Intelligence. Theory of mind was assessed with the animated triangles, emotion recognition with the Ekman faces, and flexibility with the Card Sort and Trails tests.

Results:  Data were available on 91 participants, of whom the top quartile was a priori described as having SMP.  As previously reported, SMP was associated with more generalized mood problems and conduct problems (both p<.001), but when temper tantrums symptom of conduct problems was accounted for, the association with conduct problems fell to .055, suggesting a more specific link to irritability. Intellectual ability and autism severity were not associated with SMP, however both were linked to elements of conduct problems, suggesting a more specific relationship. Associations between SMP and tasks of emotion recognition and flexibility were not significant once intellectual ability was accounted for. For this presentation, further analyses will be undertaken to include symptoms of anxiety and irritability/tempers/oppositionality to parse the independent and shared effects on mood problems and to identify the clusters of problems that exist in adolescents with autism and their neurocognitive correlates.

Conclusions:  Findings with respect to severe mood problems in adolescents with ASD suggest that the neurocognitive underpinnings of these difficulties are different from those reported in adolescents that are otherwise typically developing. A broader exploration of the psychiatric and neurocognitive correlates of severe mood problems and challenging behaviour is needed to develop effective interventions.