Words are lowercased unless there are specific rules to capitalize them. Some types of words that are always capitalized in APA Style include the following:

1) First Word of a Sentence

Capitalize the first word of a sentence. However, if a name or other proper noun that begins with a lowercase letter starts a sentence, keep the lowercase letter.

2) Proper Nouns

Always capitalize proper nouns, which include:

names of people
names of racial and ethnic groups
specific locations
specific university departments, academic institutions, and academic courses

3) Trade Names and Brand Names

Capitalize official trade names and brand names.

Zoloft, iPhone, Wi-Fi

Do not capitalize generic versions of these names.

sertraline, smartphone, wireless

4) Personal Names Within Names of Disorders, Therapies, and So On

Capitalize personal names appearing within the names of diseases, disorders, therapies, treatments, theories, concepts, hypotheses, principles, models, and statistical procedures.

Alzheimer’s disease, non-Hodgkin’s lymphoma, Pavlovian conditioning

Otherwise, use lowercase for the names of diseases, disorders, therapies, treatments, and so on.

depression, leukemia, five-factor model of personality, regression analysis

5) Job Titles and Positions

Capitalize a job title or position when the title precedes a name.

President Lincoln, Dr. Singh, Nurse Sinclair

Do not capitalize a job title or position following a name.

Lincoln was president

Do not capitalize a job title or position when referring to a position in general.

doctor, registered nurse, physician assistant, psychologist, therapist, president, manager

6) Title of Tests and Measures

Capitalize official titles of tests and measures.

Wechsler Adult Intelligence Scale

Do not capitalize generic names of tests and measures.

an intelligence test

7) Nouns Followed by Numerals of Letters

Capitalize most nouns when they are followed by numerals or letters.

Study 1, Chapter 2, Step 3