Cognitive functioning in substance abuse and dependence: a population-based study of young adults.
OBJECTIVE
To investigate whether substance use disorders (SUDs) are associated with verbal intellectual ability, psychomotor processing speed, verbal and visual working memory, executive function and verbal learning in young adults, and to study the associations of SUD characteristics with cognitive performance.


METHODS
A population-based sample (n = 466) of young Finnish adults aged 21-35 years.


METHODS
Diagnostic assessment was based on all available information from a structured psychiatric interview (SCID-I) and in- and out-patient medical records. Established neuropsychological tests were used in the cognitive assessment. Confounding factors included in the analyses were comorbid psychiatric disorders and risk factors for SUDs, representing behavioural and affective factors, parental factors, early initiation of substance use and education-related factors.


RESULTS
Adjusted for age and gender, life-time DSM-IV SUD was associated with poorer verbal intellectual ability, as measured with the Wechsler Adult Intelligence Scale-Revised (WAIS-R) vocabulary subtest, and slower psychomotor processing, as measured with the WAIS-R digit symbol subtest. Poorer verbal intellectual ability was accounted for by parental and own low basic education, whereas the association with slower psychomotor processing remained after adjustment for SUD risk factors. Poorer verbal intellectual ability was related to substance abuse rather than dependence. Other SUD characteristics were not associated with cognition.


CONCLUSIONS
Poorer verbal intellectual ability and less efficient psychomotor processing are associated with life-time alcohol and other substance use disorders in young adulthood. Poorer verbal intellectual ability seems to be related to parental and own low basic education, whereas slower psychomotor processing is associated with SUD independently of risk factors.
Latvala
Antti
A
Department of Mental Health and Substance Abuse Services, National Institute for Health and Welfare, Mannerheimintie 166, FIN-00271 Helsinki, Finland. antti.latvala@thl.fi
Castaneda
Anu E
AE
Perälä
Jonna
J
Saarni
Samuli I
SI
Aalto-Setälä
Terhi
T
Lönnqvist
Jouko
J
Kaprio
Jaakko
J
Suvisaari
Jaana
J
Tuulio-Henriksson
Annamari
A
D000328:Adult; D003072:Cognition Disorders / Q000139:chemically induced / Q000453:epidemiology / Q000523:psychology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D005387:Finland / Q000453:epidemiology; D006306:Health Surveys; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000187:drug effects / Q000502:physiology*; D012307:Risk Factors; D019966:Substance-Related Disorders / Q000453:epidemiology / Q000523:psychology*; D055815:Young Adult