Conners’ Continuous Performance Test II (Ver.5)

IPS Information Circular – March 22nd, 2015

The Conners’ CPT 3 is now available – please contact IPS (see below) for further details.

Conners’ Continuous Performance Test II (CPT II) Ver. 5.2 for Windows®
– C. Keith Conners, Ph.D. and MHS Staff with additional comments by IPS Educational Psychologist, Jenny Lyon

Important additional features of CPT II Ver. 5.2 compared with earlier versions:

• The introduction of a short practice exercise for clients prior to the administrations of the full test.
• The option to minimise false positives or false negatives.
• A Confidence Index adjustment to confirm the validity of the administration.
• The Multi-Modal Integrated report combines results from the CPT with the Conners’ Rating Scales.
• Activation Key by USB flash drive.
• Compatible with Windows Vista.

Conners’ Continuous Performance Test (CPT II) Version 5.2 for Windows® is an attention test that is widely used in ADHD research and clinical assessments for respondents aged 6 or older. Response patterns on the CPT II provide information that enables the practitioner to better understand the type of deficits that might be present. For example, some response patterns suggest inattentiveness or impulsivity, while other response patterns may indicate activation/arousal problems or difficulties maintaining vigilance.

Potential users of the CPT II include psychologists, social workers, physicians, counsellors, psychiatric workers, paediatric nurses, teachers and school officials. Appropriate settings for the CPT II include schools, outpatient clinics, inpatient clinics, residential treatment centres, child protective services for both placement and referral decisions, special education and regular classrooms, juvenile detention centres, and private practice offices (psychological, psychiatric, paediatric and family practice). The program is commonly used as a screening tool to identify potential attention problems, and as an aid in monitoring treatment effectiveness.

  • The CPT II can help determine if there has been improvement or deterioration with medication change. In addition, careful charting of CPT II scores while testing different drug dosages can often be helpful in determining the optimal dosage level.
  • Application of the CPT II program in each of these settings is well supported by both empirical evidence as well as clinical experience.
  • The CPT II is useful outside of ADHD, targeting potential problems related to executive functions such as time perception, internal ordering, working memory and motor control. The CPT II can also be used to investigate the neurological performance of individuals with attention, impulsivity, or activity control problems.

User Qualifications
Administrators of assessment instruments like the CPT II test should have an understanding of the basic principles and limitations of psychological testing, especially the interpretation of results. Although many individuals can easily supervise the CPT II test, a well-trained professional must assume the ultimate responsibility for its use and interpretation.

Qualified users of this instrument should know the standards for psychological testing developed by the American Psychological Association, and should belong to professionals associations that endorse a set of standards for the ethical use of psychological needs or possess a license to practice psychology, medicine, social work, or an allied discipline. Individuals whose only exposure to testing is gained from this program and its manual will not, in general, be qualified users of the CPT II test. In clinical settings, the person responsible for interpretation should possess an advanced degree, such as a Ph.D, Ed.D., M.D., or M.A. in the social, medical or behavioural sciences.

Like previous versions of the Conners’ CPT test, the CPT II Version 5.2 for Windows® employs the unique Conners’ paradigm that has been based on extensive research and theory. The theoretical background and development of the instrument is provided in the CPT II Technical Guide and Software Manual.

The standard protocol of the CPT II test uses a short practice exercise prior to the administration of the full test to ensure that the respondent fully understands the task prior to proceeding. After the practice exercise, a new administration is begun and it is a requirement of the standard protocol that an administrator remains present while the administration is taking place. CPT II respondents are required to press the space bar or click the mouse whenever any letter except the letter ‘X’ appears on the computer screen. The inter-stimulus intervals (ISIs) are 1, 2 and 4 seconds with a display time of 250 milliseconds. The unique CPT paradigm is a test structure consisting of 6 blocks and 3 sub-blocks, each containing 20 trials (letter presentations). The presentation order of the different ISIs varies between blocks.

The following types of measures are provided by the CPT II program: Response Times – Overall Hit Reaction Time (HRT), Overall HRT Standard Error (SE), Variability, HRT by Block, HRT SE by Block, HRT by ISI, HRT SE by ISI (the program classifies a reaction time less than 100 ms as a perseveration); Errors (omissions and commissions); by Block results; by ISI results (the change in reaction time and in consistency); and Signal Detection Theory Statistics (Confidence Index that suggests closeness of the match to a clinical or non-clinical profile). Additional meaning, calculation methods and interpretive value of the measures are further described in the CPT II Technical Guide and Software Manual. To facilitate the interpretation process, T-scores and percentiles are available relative to two normative groups; the general population (non-clinical sample) and an ADHD clinical sample. Scoring can be done immediately and automatically after a CPT II administration.

Features that increase the flexibility of the program are included in this version. That is, you can enable the option to ‘Minimize False Positives’, which means that the program’s computations will focus on indicating potential attention problems only when results show extremely strong evidence. This scoring option can be very useful in some contexts, as it helps reduce unnecessary follow-up investigations. The option to ‘Minimize False Negatives’ is also available. When this option is enabled, the program is oriented to detect as many potential attention problems as possible. This option is also useful in some clinical contexts, but some respondents without attention problems may be flagged for follow-up investigation.

In addition, the results include a Confidence Index Adjustment – a timing verification to confirm the validity of the administration – and an individual administration warning if standard protocol has been compromised. The CPT II program gives you a number of report options that include tables, graphs, and interpretive guidelines to organise the administration results.

The CPT II Version 5.2 for Windows® offers three types of reports to help organise test results. The Profile Report allows you to select the types of tables, text, and graphs to be included in a generated report for a single administration. One of the tables included in the report, the Overall table, contains all the measures used in the program, while other tables contain measures that pertain specifically to inattention, impulsivity, or vigilance. Other options are available, such as the General Population option, which includes a profile graph showing T-scores for each measure relative to the general population and to ADHD assessments, as well as tables of raw scores, T-scores, and percentiles relative to the general population norms. The Block Data option includes graphs and tables that show Hit RT and Hit RT SE T-scores by ISI collapsed and ISI expanded, for both the general population and ADHD population data.

The Progress Report allows you to select up to 4 administrations to be included in the report to easily monitor changes in a client’s CPT scores over the course of treatment. The Multimodal Integrated Report combines results from the CPT II Version 5.2 for Windows® program with selected administrations of up to three Conners’ Rating Scores – Revised (CRS-R) assessments (i.e. self, parent, and teacher), or from up to three Conners’ Adult ADHD Rating Scales (CAARS) assessments (i.e. self and observers), providing an informative overview of ADHD-related behaviour and functioning. Inclusion of multiple respondents (i.e. parent, teacher, or observer) will help to determine the degree of consensus and establish pervasiveness of behaviour across contexts in accordance with DSM-IV™ diagnostic criteria. For example, information obtained using the CRS-R or CAARS assessments can include evaluations of the client by family members, teachers or friends, providing insight on the client’s current behaviour, school behaviour, academic performance, emotional problems, and family history.

The CPT II Version 5.2 for Windows® is an unlimited-use software program and is launched from SmartLink, MHS’ latest client-management software. MHS SmartLink™ offers fast report generation, enhanced client-searching capabilities, and flexible multi-user security. From MHS SmartLink™ you can change terminology preferences (e.g. change client to patient), change your password, work with assessor files, and work with a database of diagnostic codes. The MHS SmartLink™ and CPT II V.5.1 software can be customised for use with existing client-management systems.

The CPT II data sample consists of 2686 subjects. Of these subjects, 378 were classified as clinical and diagnosed with ADHD, and 223 were classified as clinical with some type of neurological impairment. The non-clinical sample included 1920 individuals from the general public.

Scientific Validation
The CPT II Technical Guide and Software Manual provides research results pertaining to the reliability and validity of the CPT II based on the normative databases. Two types of reliability information – Split-half Reliability and Standard Error – provide support for the psychometric soundness of the CPT II test. The CPT II test shows adequate consistency in terms of Split-half Reliability, and the Standard Error measurement values show that scores from the instrument are a reasonable match to the true performance of individuals.

Statistical validation is provided to demonstrate that CPT II scores are significantly different for the general population and clinical groups. In addition, hit rates are provided to evaluate the classification accuracy of the test. The CPT II has satisfactory accuracy in terms of both false negatives and false positives. The results also suggest that the CPT II can provide observational and descriptive support in clinical contexts.

Supporting Literature
Conners, K. and Jeff, J.L. (1999) ADHD in adults and children: The latest assessment and treatment strategies. Kansas City, MO: Compact Clinicals

Goldstein, S. and Goldstein, M. (1998) Managing ADHD in children: A guide for practitioners. New York: John Wiley and Sons.

© MHS 2015 and International Psychology Services

Additional Information
Ages: 6 and older
Administration: Client-completed
Administration Time: 14 minutes
Qualification Level: B
Formats: Software
Key Areas Measured:
Response Times
Change in Reaction Time Speed and Consistency
Signal Detection Theory Statistics
Overall Statistics (confidence index and overall index)
Omission Errors
Commission Errors

The CPT II is widely used with psychiatric and general medical patients to assess attention disorders and neurological functioning. When used with the CRS-R, it adds a task-oriented component to support parent and teacher ratings. It can also be used with offenders, where there is a higher than average rate of adolescent and adult ADHD. To complete the CPT II V.5.2, respondents react to target letters on the screen. The unique Conners paradigm still forms the basis of the program.

System Requirements
Windows NT 4, Windows 2000, Windows XP/XPro, Windows Vista are requirements for running the latest software. It is not recommended to run the CPT on a Mac system, with Windows emulation, although we can offer advice for utilising a Mac with an Intel-based processor.

CPT Reviews available here

The Conners’ Continuous Performance Test II (Windows® Version 5.2) is available in Europe from IPS (International Psychology Services) in the UK.

The current cost of the CPT II is £565 Sterling (approx. Euro €775), including insurance and delivery. IPS accepts MasterCard / Visa / PayPal direct payments to our UK Sterling bank acccount and UK institutional purchase orders. If based in North America please contact us for US pricing.

Discounts are available for network installlations.

Please note that UK VAT of 20% is charged to EEC customers who are not registered for VAT. Customers outside the EEC are not charged VAT. If resident in the EEC, please supply your VAT registration number when ordering.

Upgrade – Details of the CPT 3 are now available – please contact IPS for further information.

Contact: IPS (International Psychology Services)

17 High Street, Hurstpierpoint, West Sussex, England BN6 9TT

Telephone 01273 832255 email:

from overseas telephone (44) 1273 832255