One of the reference guides used by clinicians to diagnose mental health disorders is known as the Diagnostic and Statistical Manual of Mental Disorders (DSM). The most recent version of the manual, the Diagnostic and Statistical Manual of Mental Disorders – 5th Edition (DSM-5), was released in May 2013. Prior to this, the Diagnostic and Statistical Manual of Mental Disorders – 4th Edition, Text Revision (DSM-IV-TR) was used by clinicians and researchers from 2000 to 2013.

The diagnostic criteria for mental health disorders due to pharmaceutical drug use differ significantly between the DSM-IV-TR and the new DSM-5.  For the purposes of the NADK, all reported data on pharmaceutical drug-related mental health disorders utilise the DSM-IV-TR diagnostic criteria. This is because the relevant mental health data reported in the NADK were collected prior to the publication of the newer version of the DSM (DSM-5).

DSM-IV-TR Diagnostic Criteria

According to the DSM-IV-TR, there are two main pharmaceutical drug-related mental health disorders: substance dependence and substance abuse. The diagnostic criteria for each are presented below.

Substance Dependence

A maladaptive pattern of substance use, leading to clinically significant impairment or distress, as manifested by three (or more) of the following, occurring at any time in the same 12-month period:

1. Tolerance, as defined by either of the following:

1. A need for markedly increased amounts of the substance to achieve intoxication or desired effect; or
2. Markedly diminished effect with continued use of the same amount of the substance

2. Withdrawal, as manifested by either of the following:

1. The characteristic withdrawal syndrome for the substance; or
2. The same (or a closely related) substance is taken to relieve or avoid withdrawal symptoms

3. The substance is often taken in larger amounts or over a longer period than was intended
4. There is a persistent desire or unsuccessful efforts to cut down or control substance use
5. A great deal of time is spent on activities necessary to obtain the substance (e.g., visiting multiple doctors or driving long distances), use the substance, or recover from its effects
6. Important social, occupational, or recreational activities are given up or reduced because of substance use
7. The substance use is continued despite knowledge of having a persistent physical or psychological problem that is likely to have been caused or exacerbated by the substance.

Substance Abuse

A maladaptive pattern of substance use leading to clinically significant impairment or distress, as manifested by one (or more) of the following, occurring within a 12-month period:

1. Recurrent substance use resulting in a failure to fulfil major role obligations at work, school, or home (e.g., repeated absences or poor work performance related to substance use; substance‐related absences, suspensions, or expulsions from school; neglect of children or household)
2. Recurrent substance use in situations in which it is physically hazardous (e.g., driving an automobile or operating a machine when impaired by substance use)
3. Recurrent substance‐related legal problems (e.g., arrests for substance‐related disorderly conduct)
4. Continued substance use despite having persistent or recurrent social or interpersonal problems caused or exacerbated by the effects of the substance (e.g., arguments with spouse about consequence of intoxication, physical fights).

DSM-5 Diagnostic Criteria

According to the DSM-5, there is one main substance related mental health disorder: A substance use disorder.

A substance use disorder is defined as:

A pattern of substance use leading to clinically significant impairment or distress, as manifested by at least two of the following, occurring within a 12-month period:

1. The substance is often taken in larger amounts or over a longer period than was intended
2. There is a persistent desire or unsuccessful efforts to cut down or control substance use
3. A great deal of time is spent in activities necessary to obtain the substance, use the substance, or recover from its effects
4. Having craving, or a strong desire or urge to use the substance
5. Recurrent substance use resulting in a failure to fulfil major role obligations at work, school, or home
6. Continued substance use despite having persistent or recurrent social or interpersonal problems caused or exacerbated by the effects of the substance
7. Important social, occupational, or recreational activities are given up or reduced because of substance use
8. Recurrent substance use in situations in which it is physically hazardous
9. Substance use is continued despite knowledge of having a persistent or recurrent physical or psychological problem that is likely to have been caused or exacerbated by the substance

10. Tolerance, as defined by either of the following:

1. A need for markedly increased amounts of the substance to achieve intoxication or desired effect.
2. A markedly diminished effect with continued use of the same amount of the substance.

11. Withdrawal, as manifested by either of the following:

1. The characteristic withdrawal syndrome for the substance
2. The substance (or a closely related substance) is taken to relieve or avoid withdrawal symptoms.

A mild substance use disorder is defined as the presence of 2-3 of the above symptoms.

A moderate substance use disorder is defined as the presence of 4-5 of the above symptoms.

A severe substance use disorder is defined as the presence of 6 or more of the above symptoms.