Drug Abuse and Mental Illness: Which Comes First? Jake M Najman, PhD FASSA Professor and Director

Major focus on research Does substance (licit and illicit) use lead to mental illness? Need to test for the possibility that substance use represents ‘self-medication’ i.e. Emotionally disturbed individuals who use drugs for relaxation and relief

What needs to be known Age of onset Duration of disorder Duration to first and subsequent recurrences Frequency of recurrence Factors which determine onset Factors which determine recurrences Natural history over the life course Impact of help seeking and treatment on the natural history

Disorders which are the focus of our research Alcohol abuse/dependence Nicotine abuse/dependence Illicit drug use disorders –Cannabis –Amphetamines

Previous population based research using the Composite International Diagnostic Interview (CIDI) has found high frequencies of mental illness in the population and remarkably young ages of onset for many mental illnesses

National Comorbidity Survey Replication (NCSR Kessier et al, 2005) National representative sample of persons 18yrs + in the USA Face-to-face interviews. Feb 2001 – April 2003 Diagnostic assessment using the World Mental Health Composite International Diagnostic Interview (WMH-CIDI) Produces DSM-IV and ICD-10 Diagnoses

Retrospective age-of-onset reports “Can you remember your exact age the very first time you HAD THE SYNDROME?” For those who answered NO = probe of time found eg. “Was it before you started school?” Upper end of bound used if bound was selected.

Age of Onset of CIDI- II Disorders (NCSR Kessler et al, 2005) Onset Percentiles Any Anxiety Disorder Any Depressive Disorder Any Impulse Control Disorder Any Substance use Disorder 55yrs11yrs5yrs15yrs 105yrs13yrs6yrs16yrs 256yrs18yrs7yrs18yrs 5011yrs30yrs11yrs20yrs 7521yrs43yrs15yrs27yrs 9041yrs54yrs18yrs37yrs

Began in January December All public patients enrolled at their First (Obstetrical) Clinic Visit (FCV). In all, 8556 consecutive patients invited to participate; 8458 agreed to participate in the study. Of the 8,458 agreeing to participate in the study, about 7,332 infants were discharged alive from the study hospital. There were some 170 miscarriages, and 300 mothers moved to another location for the birth. Mater-University of Queensland Study of Pregnancy (MUSP)

At entry Questionnaire administered average 18 weeks gestation at first clinic visit At birth Questionnaire administered 3-5 days after the birth At 6 months Questionnaire administered via telephone follow-up About 90 per cent of mothers giving birth responded to this questionnaire

At 5 years Questionnaire administered in hospital or at home to mothers Child assessed by Paediatric Researcher About 70 per cent of mothers giving birth responded to this questionnaire At 14 years Questionnaire administered in hospital or at home to mother and child Child assessed by Paediatric Researcher About 70 per cent of mothers and children participated in this phase

At 21 year F/U Questionnaire administered at home to mother and youth Physical assessments –Blood pressure –Lung function –Physique –CIDI – computer administered

MUSP27 is currently underway. It involves a 27 year follow up of the mothers with a focus on mental and physical health of the women as they progress through menopause

MUSP30 is scheduled to begin January It is a 30 year follow up of the children with a focus on cardiovascular disease, metabolic syndrome, mental illness and substance use and abuse. It involves the collection of blood samples and a study gene-environment interactions.

MUSP Findings

DSM-IV Diagnoses at 21yr Follow-up Lifetime (%) 12 months (%) Anxiety Depression Alcohol use disorder Nicotine use disorder Cannabis use disorder Amphetamine use disorder *Sample sizes vary between 2,549 – 2,572.

CIDI-II – Anxiety Disorders at 21 Yr Follow-up – MUSP Age of Onset - Anxiety Mean = 11.3 yrs N% 10 yrs or less yrs yrs yrs yrs yrs yrs

CIDI-II –Depression at 21 Yr Follow-up – MUSP Age of Onset - Depression Mean = 16.6 yrs N% 10 yrs or less yrs yrs yrs yrs yrs yrs

CIDI-II – Alcohol Use Disorder at 21 Yr Follow-up – MUSP Age of Onset - Alcohol Abuse Mean = 17.3 yrs N% 10 yrs or less yrs yrs yrs yrs yrs yrs

CIDI-II – Nicotine Use Disorder at 21 Yr Follow-up – MUSP Age of Onset - Nicotine Dependence (Mean = 17.5 yrs) N% 10 yrs or less yrs yrs yrs yrs yrs yrs

CIDI-II – Cannabis Use Disorder at 21 Yr Follow-up – MUSP Age of Onset - Cannabis Abuse (Mean = 16.4 yrs) N% 10 yrs or less yrs yrs yrs yrs yrs yrs

CIDI-II – Amphetamine Use Disorder at 21 Yr Follow-up – MUSP Age of Onset - Amphetamine Abuse (Mean = 17.4 yrs) N% 10 yrs or less yrs yrs yrs yrs yrs yrs

Mean age of onset NYears Anxiety disorder Cannabis use disorder Depression disorder Alcohol use disorder Amphetamine use disorder Nicotine use disorder

What occurs first; mental illness (anxiety or depression) or substance use disorders?

By age 21, 34.1% of those with anxiety disorder and 30.2% of those with alcohol disorder have had both disorders 631 with Anxiety 712 with Alcohol

81.3% Anxiety preceded Alcohol 7.5% Anxiety and Alcohol in same year 11.2% Alcohol preceded anxiety 214 with Anxiety and Alcohol

By age 21, 31.5% of those with anxiety disorder and 47.6% of those with nicotine disorder have had both disorders 641 with Anxiety 424 with Nicotine

82.6% Anxiety precedes Nicotine 7.2% Anxiety and Nicotine in same year 10.3% Nicotine precedes Anxiety 195 with Anxiety and Nicotine

By age 21, 28.8% of those with an anxiety disorder and 32.5% of those with a cannabis disorder have had both disorders 628 with Anxiety 557 with Cannabis

180 with Anxiety and Cannabis Use 77.2% Anxiety precedes Cannabis 7.2%Anxiety precedes Cannabis in same year 15.6% Cannabis precedes Anxiety

By age 21, 4.3% of those with an anxiety disorder and 25.7% of those with an amphetamine disorder have experienced both disorders 629 with Anxiety 105 with Amphetamine

27 with Anxiety and Amphetamine Use 77.8% Anxiety precedes Amphetamine Use 3.7% Anxiety precedes Amphetamine Use same year 18.5% Amphetamine Use precedes Anxiety

Anxiety almost always precedes : Alcohol disorder Nicotine disorder Cannabis use disorder Amphetamine use disorder

546 with Depression 711 with Alcohol By age 21, 36.1% of those with depression and 27.7% of those with an alcohol disorder have had both disorders

40.1% Depression precedes Alcohol 23.9% Depression and Alcohol in same year 36.0% Alcohol precedes Depression 197 with Depression and Alcohol

550 with Depression 421 with Nicotine By age 21, 30.2% of those with depression and 39.4% of those with a nicotine disorder have had both disorders

50.6% Depression precedes Nicotine 21.1% Depression and Nicotine in same year 28.3% Nicotine precedes Depression 166 with Depression and Nicotine

545 with Depression 557 with Cannabis By age 21, 31.7% of those with depression AND 31.1% of those with cannabis disorders have experienced both disorders

173 with Depression and Cannabis Use 37.0% Depression precedes Cannabis 19.1% Depression precedes Cannabis same year 43.9% Cannabis precedes Depression

545 with Depression 105 with Amphetamine Use By age 21, 6.8% of those with depression AND 35.2% of those with an amphetamine disorders have experienced both disorders

37 with Depression and Amphetamine Use 35.1% Depression precedes Amphetamine 32.4% Depression precedes Amphetamine same year 32.4% Amphetamine precedes Depression

Generally depression precedes: Alcohol use disorder Nictotine use disorder

Depression occurs equally before and after the following disorders: Cannabis use disorder Amphetamine use disorder

Summary of findings All mental disorders commonly have a young age of onset Where co-occurrence with anxiety, then anxiety tends to precede substance abuse disorders – Is this self-medication?

Summary of findings (cont’d) Where co-occurrence with depression, then depression tends to precede alcohol and nicotine disorder; but often occurs before and after cannabis and amphetamine use disorders To detect the negative mental health consequences of substance abuse disorders, need to adjust for previous mental health problems

Conclusions There is a high level of use of substance by those who have a pre-existing mental illness. It is as likely that mental illness leads to substance use as substance use leads to mental illness. For some mental illnesses and substances there is high co-occurrence e.g. anxiety, depression and smoking which for others a low level of co- occurrence e.g. Anxiety, depression and amphetamine use