Table 1.

Defining features of nine psychiatric disorders ^‡

Abbrev.	Name	Life prev	Heritability	Essential characteristics	Notable feature
AD	Alzheimer’s disease	0.132	0.58	Dementia, defining neuropathology	Of the top 10 causes of death in the US, AD alone has increasing mortality
ADHD	Attention-deficit hyperactivity disorder	0.053	0.75	Persistent inattention, hyperactivity, impulsivity	Costs estimated at ~$US 100×109/year
ALC	Alcohol dependence	0.178	0.57	Persistent ethanol use despite tolerance, withdrawal, dysfunction	Most expensive psychiatric disorder (total costs exceed $US 225×109/year)
AN	Anorexia nervosa	0.006	0.56	Dangerously low weight from self-starvation	Notably high standardized mortality ratio
ASD	Autism spectrum disorder	0.001	0.80	Markedly abnormal social interaction and communication beginning before age 3	Huge range of function, from people requiring complete daily care to exceptional occupational achievement
BIP	Bipolar disorder	0.007	0.75	Manic-depressive illness, episodes of mania usually with MDD	As a group, nearly as disabling as SCZ
MDD	Major depressive disorder	0.130	0.37	Unipolar depression, marked and persistent dysphoria with physical/cognitive symptoms	Ranks #1 in burden of disease in world
NIC	Nicotine dependence	0.240	0.67	Persistent nicotine use with physical dependence (usually cigarettes)	Major preventable risk factor for many diseases
SCZ	Schizophrenia	0.004	0.81	Long-standing delusions and hallucinations	Life expectancy decreased by 12–15 years

^‡ Most of these definitions are made more restrictive by requiring persistence over time (e.g., the criteria for SCZ require ≥6 months of symptoms), significant impairment, and presence across multiple different contexts. See Table S1 for more detail. Additional sources are references ^{1,2,181–183}.