Psychologists rely on a wide range of tools, from standardized tests and diagnostic manuals to physical therapy equipment and digital platforms. Some tools help with diagnosis, others guide treatment, and many do both. The specific combination depends on whether a psychologist works in clinical assessment, therapy, research, or a specialty like child or neuropsychology.
Diagnostic Manuals
The two primary references psychologists use to diagnose mental health conditions are the Diagnostic and Statistical Manual of Mental Disorders (DSM-5-TR), published by the American Psychiatric Association, and the International Classification of Diseases (ICD-11), approved by the World Health Assembly. These manuals define what qualifies as a clinical disorder, listing the specific symptoms and thresholds required before a diagnosis can be made.
The DSM-5-TR is the version most commonly used in the United States. It was updated in 2022 with several notable changes: new diagnoses including Prolonged Grief Disorder and Unspecified Mood Disorder, updated criteria for more than 70 existing disorders, and new codes that let clinicians record suicidal behavior or nonsuicidal self-injury independent of any psychiatric diagnosis. Terminology was also modernized, replacing “desired gender” with “experienced gender” and “conversion disorder” with “functional neurological syndrome,” among other changes.
The ICD-11 is used more broadly around the world. The two systems overlap significantly but differ in some structural ways. For personality disorders, the DSM-5-TR retains ten specific categories, while the ICD-11 takes a different approach: first determining whether a personality disorder exists at all, then rating its severity, then describing its features using trait-based descriptors. These differences reflect different interpretations of the same body of evidence.
Intelligence and Cognitive Testing
When psychologists need to measure intellectual ability, they typically turn to the Wechsler scales. The most widely used version for adults is the WAIS-IV, standardized on 2,200 people between ages 16 and 90 in the United States. It includes 10 core subtests that produce scores across four areas: verbal comprehension, perceptual reasoning, working memory, and processing speed. These four scores combine into a full-scale IQ. Five supplemental subtests are available when a core subtest can’t be completed, for instance if someone has motor difficulties that prevent them from manipulating physical blocks.
Children are assessed with the WISC (now in its fifth edition), which follows a similar structure but is calibrated for younger age ranges. These tests aren’t just used for curiosity about IQ. Psychologists use them to identify learning disabilities, assess the cognitive impact of brain injuries, evaluate developmental delays, and inform decisions about educational placement.
Cognitive Screening Tools
For quicker assessments of cognitive function, particularly when screening for dementia or cognitive decline in older adults, psychologists use brief screening instruments. The Montreal Cognitive Assessment (MoCA) is one of the most common. It takes about 10 minutes to administer and is scored out of 30, with 26 or above considered normal. An extra point is added for individuals with 12 or fewer years of education. These screening tools don’t replace full neuropsychological testing, but they flag who needs it.
Personality and Symptom Assessments
Personality tests help psychologists understand a person’s characteristic patterns of thinking, feeling, and behaving. They’re also used to screen for psychopathology and to evaluate whether someone might be exaggerating or minimizing symptoms.
The Personality Assessment Inventory (PAI) is widely used for evaluating psychiatric symptoms and personality characteristics. It includes built-in validity checks: scales that detect whether someone is presenting themselves in an overly negative or positive light, responding inconsistently, or giving unusual answers. Clinical scales cover areas like somatic complaints, depression, anxiety, schizophrenia-related symptoms, paranoia, and suicidal ideation. A newer embedded scale, the Cognitive Bias Scale, was developed specifically to flag individuals whose self-reported cognitive complaints don’t match their actual test performance.
The MMPI (Minnesota Multiphasic Personality Inventory), now in its third edition, is another cornerstone personality assessment. Both the PAI and MMPI are self-report questionnaires where clients rate how well various statements describe them, and both are used extensively in clinical, forensic, and employment settings.
Therapy Worksheets and Tracking Tools
In cognitive behavioral therapy (CBT), one of the most common hands-on tools is the thought record. This is a structured worksheet with seven prompts that walk a person through examining their own thinking patterns. You start by describing a situation and how it made you feel, then list the unhelpful thoughts that came up. Next, you write down evidence that supports those thoughts and evidence that contradicts them. Then you generate an alternative, more realistic thought. The final step is noting how your feelings have changed after working through the process.
The therapeutic value comes from the comparison between step two (how you felt initially) and step seven (how you feel afterward). Over time, repeated use of thought records helps people recognize their own cognitive patterns and develop the habit of questioning automatic negative thoughts before they spiral. Psychologists also use mood tracking sheets, behavioral activation schedules (which map daily activities against mood to identify what helps and what doesn’t), and exposure hierarchies for anxiety-related conditions.
EMDR Equipment
Eye Movement Desensitization and Reprocessing (EMDR) is a trauma therapy that requires specific physical tools to create bilateral stimulation, meaning rhythmic sensory input that alternates between the left and right sides of the body. The original method involved a therapist moving their hand back and forth while the client tracked it with their eyes. Modern practitioners often use light bars instead, which project a moving light at adjustable speeds so the therapist doesn’t develop shoulder fatigue from hours of hand movements.
Light bars are considered the flagship tool for EMDR. Many systems come as complete kits that include a light bar (often LED and Bluetooth-operated), handheld tactile pulsers or “tappers” that vibrate alternately in each hand, headphones for auditory bilateral stimulation, and a remote control. Some psychologists use simpler setups or just handheld buzzers. The choice often depends on client preference, since some people respond better to visual stimulation while others prefer tactile or auditory input.
Play Therapy and Child Psychology Tools
Working with children requires a fundamentally different toolkit. Young children often can’t articulate their inner experiences through conversation, so psychologists use play as the medium for assessment and therapy. A well-equipped play therapy room includes sand trays, miniature figures, dollhouses, art supplies, and puppets.
Sand tray therapy is especially common. Clients choose from a large collection of small figures and arrange them in a tray of sand to create scenes that represent their feelings or experiences. The miniatures are carefully curated to span a wide range of themes: diverse doll families for exploring family dynamics, emotion stones for feelings work, animals, fantasy and mythological figures, battle and warfare items, fences and boundaries, medical and trauma-related objects, containers, and symbolic items representing death, grief, faith, or hope. A therapist typically provides many categories freely available for the client to choose from, since the selection process itself reveals what’s on the child’s mind.
Biofeedback Devices
Biofeedback tools measure real-time physiological signals and display them on a screen so a client can learn to influence their own body’s stress response. Heart rate variability (HRV) biofeedback is one of the most studied forms. It uses sensors, either electrocardiogram patches or simpler finger-clip plethysmographs, to measure the variation in time between heartbeats. Clients then practice breathing techniques while watching their HRV readings, learning to shift their nervous system toward a calmer state.
This approach was once limited to expensive clinical-grade equipment, but affordable options are now available for private practice settings. HRV biofeedback has been applied to anxiety, PTSD, and substance use disorders, among other conditions. Neurofeedback, a related tool, uses EEG sensors placed on the scalp to monitor brainwave patterns and train clients to modify them, though it requires more specialized equipment and training.
Electronic Health Records and Practice Software
Behind every clinical interaction, psychologists depend on digital systems to manage their practice. Electronic health records (EHRs) designed for mental health providers handle scheduling, billing, clinical documentation, and secure communication. Many offer add-on features like e-prescribing (for psychologists with prescribing privileges in certain states), pre-populated note templates, patient portals, and voice dictation.
Privacy is a particular concern in mental health. HIPAA provides extra safeguards for psychotherapy notes stored in an EHR, and most vendors will adapt their systems to the needs of individual practices. If a psychologist routinely uses specific screening tools or outcome measures, many vendors can integrate those directly into the system, though this usually costs extra. The American Psychiatric Association recommends using clearinghouses like Capterra to compare options and talking to peers in similar practice settings before choosing a platform.
Teletherapy platforms have also become standard. HIPAA-compliant video tools allow psychologists to conduct sessions remotely, and many EHR systems now include built-in telehealth functionality alongside automated intake forms that clients complete before their first appointment.