Table 2.

Sex differences in neuropsychiatric, neurological and neurodegenerative conditions

Condition	Sex differences in prevalence	Sex differences in onset	Sex differences in phenotype	Refs
Neuropsychiatric conditions with origins in development
Autism spectrum disorder	Four to five times higher in males than in females	None	More social impairment in males; more affective symptoms in females	87,88, 162,163
Conduct disorder oppositional defiance disorder	Three times higher in males than in females	Earlier onset in males	More externalizing symptoms in males; more affective symptoms in females	164,165
ADHD	Two to three times higher in males than in females	None	More hyperactivity, externalizing and impulsivity in males; more internalizing, inattention and intellectual impairment in females	166,167
Schizophrenia	1.42 times higher in males than in females	Earlier onset in males than in females (early onset is more likely in males; late onset is more likely in females)	More language disruption, positive symptoms and severe course of illness in males; more affective symptoms in females	98,99, 168–170
Neurological developmental conditions
Dyslexia and/or reading impairment	Two to three times higher in males than in females	None	None known	104,105
Stuttering	2.3 times higher in males than in females	Adolescent onset four times higher in males than females	None known	103
Tourette syndrome	Three to four times higher in males than in females	Earlier onset in males	Greater tic severity in adulthood in females	106
Adult onset neuropsychiatric conditions
Major depression	None before puberty; two times higher in females than in males post-puberty	None	None known	171–175
Bipolar disorder	None for bipolar I; bipolar II higher in females than in males	Earlier onset in males	Sex by genotype interaction	176–179
Generalized anxiety	Two times higher in females than in males	None	Higher chronicity and comorbidity with major depression in females	174, 180–182
Panic disorder	2.5 times higher in females than in males	None	None known	180
OCD	1.5 times higher in females than in males	None	None known	183
PTSD	Two times higher in females than in males	None	More likely in females than in males following childhood trauma	184,185
Anorexia nervosa	Three times higher in females than in males	Unknown	None known	186–189
Bulimia	Three to four times higher in females than in males	Unknown	None known	186–189
Alcoholism or substance abuse	Higher in males than in females	Earlier in females than males	Females progress to addiction more quickly than males	190
Adult neurological conditions
Migraine	None pre-puberty, but three times higher in females than males post-puberty	None	None known	191,192
Stroke	Higher in males than females before age 85, but higher in females than males after age 85	Males 4 years before females	None known	193,194
Neurodegenerative disease
MS (with exception of primary progressive MS)	Two times higher in females than males	Earlier onset in females	More severe in males	195–197
Alzheimer disease	1.5–2 times higher in females than males, especially in those over 80 years	Earlier onset in females	More tangles and global pathology in females; pathology more highly correlated with clinical score in females	198–201
Parkinson disease	1.5 times higher in males than females	Males 2 years before females	None known	202
ALS	Three times higher in males than females	Earlier onset in males	None known	197,203
Myasthenia gravis	Four times higher in females than males	Earlier onset in females	None known	196

ADHD, attention deficit hyperactivity disorder; ALS, amyotrophic lateral sclerosis; Bipolar I, bipolar spectrum disorder characterized by at least one manic or mixed episode; Bipolar II, bipolar spectrum disorder characterized by at least one episode of major depression lasting two or more weeks and at least one hypomanic episode; MS, multiple sclerosis; OCD, obsessive compulsive disorder; PTSD, post-traumatic stress disorder.