Genome-wide approaches to study CNVs are currently being applied to other psychiatric disorders such as ADHD and bipolar disorder. Further research is necessary to conclusively determine whether large, recurrent CNVs that confer susceptibility to these psychiatric disorders overlap, subsume, or are independent of the current models. Early results have shown mixed findings in terms of genetic burden of CNVs in the few studies emerging for these disorders. GWAS ADHD results did not find an increase in rare CNVs66 yet an increase was noted in large, rare CNVs.26 This finding has now been replicated in a very convincing CNV study in a large cohort of twins with attentional problems.67 Specific CNVs identified in ADHD include 15q13.368 and 16p13.1126 (especially significant in comorbid ADHD and ID) and these CNVs have both been found in ID, ASD, schizophrenia, and epilepsy. Bipolar disorder GWAS studies have been mixed in terms of CNV burden.69–71 McCarthy et al.16 conducted a meta-analysis and found 16p11.2 (specifically duplications) highly enriched in bipolar disorder, which has also been identified in ID, ASD, schizophrenia, and epilepsy. However, additional studies have
