Employment Offer Letter, dated April 2, 2018, between the Registrant and Elena Ridloff

Base Salary. Your semi-monthly salary will be $17,708.34 ($425,000 annualized). As an employee of ACADIA, you will be expected to abide by the Company’s rules and regulations and to devote all of your business time, skill, attention and best efforts to ACADIA business to fulfill the responsibilities assigned to you. Your position is full time and is exempt under the Fair Labor Standards Act (“FLSA”) provision for overtime.

Performance Bonus. You will be eligible to receive a discretionary annual performance bonus (“Annual Bonus”) currently targeted at 40% of your annual base salary but which will be granted in the sole discretion of the Board based upon its evaluation of the Company’s and your achievement of such specific performance goals as established by the Board.  Your Annual Bonus for 2018, if any, will be pro-rated based on your time at the Company in 2018.  You must be an employee of the Company on the date upon which any annual bonus is paid to be eligible for such bonus.

Stock Options.

Initial Grant. In connection with the commencement of your employment, subject to standard Board approval, the Company will grant you an option (the “Option”) to purchase 100,000 shares of the Company’s Common Stock (the “Shares”) at an exercise price equal to the fair market value of the common stock on the date of grant, as determined in accordance with the terms of the Company’s 2010 Equity Incentive Plan (the “Plan”).

Vesting. The Option will vest over four (4) years, with twenty-five percent (25%) of the Shares vesting on the first anniversary of the date of grant and 1/48th of the Shares vesting monthly thereafter on the monthly anniversary of the date of grant provided that you remain employed by the Company through each vesting installment date.

Other Terms. These Options will be subject to the terms of the Plan, a related stock option agreement, and a notice of stock grant that must be acknowledged as received by you.

Severance Benefit. You will be entitled to participate in our Management Severance Benefit Plan (“Severance Plan”). In the event of a qualifying termination of employment and subject to the terms of the Severance Plan, you would be entitled to receive the benefits set forth in the

Severance Plan. The amount of payments and the type of benefits provided under the Severance Plan include cash severance payments based on base salary and bonus and payment for group healthcare benefits you were receiving at the time of your termination (subject to the terms of the Company’s benefit plans). This description is qualified in its entirety by the terms of the Severance Plan.

Change in Control Severance Benefit. You will be entitled to participate in our Change in Control Severance Benefit Plan (“CIC Severance Plan”). In the event of a qualifying termination of employment, up to one month prior to or within 18 months following certain change in control events set forth in the CIC Severance Plan, you would be entitled to certain severance payments and benefits as outlined in the CIC Severance Plan. The amount of payments and the type of benefits provided under the CIC Severance Plan include cash severance payments based on base salary and bonus, accelerated vesting of equity awards, and payment for group healthcare benefits you were receiving at the time of your termination (subject to the terms of the Company’s benefit plans). These benefits would supersede the severance benefits described in paragraph 4, above. This description is qualified in its entirety by the terms of the CIC Severance Plan.

Benefits. You will be eligible to participate in the Company’s standard benefit plans, which include medical, dental, vision, life, accidental death and dismemberment and short and long-term disability insurance coverage. You will also be able to utilize a Flexible Spending Arrangement that allows employees the opportunity to pay for certain dependent care and health care related costs with pretax dollars. Note that these plans for new employees are effective as of the first day of the calendar month following your employment start date and enrollment. Your eligibility and participation in these plans, is, of course, subject to the terns of the plans themselves. Additionally, ACADIA carries D&O insurance and as a Sr. Vice President you will be covered under this policy.

Vacation. You will receive 20 vacation days each year, accrued monthly.

401K. You will have the opportunity to participate in the Company’s 40l(k) plan. Currently, the plan provides for the Company to match, on a dollar-for-dollar basis, the employee contributions to the plan up to 5% of the employee’s annual compensation, subject to limitations imposed by the Internal Revenue Service. The plan is currently managed by Fidelity Investments and provides for enrollment on the first day of each fiscal quarter.

Employee Stock Purchase Plan. You will have the opportunity to enroll in the next offering that commences after your start date under the Company’s Employee Stock Purchase Plan (ESPP), which provides for the purchase of shares of ACADIA common stock through payroll deductions. The ESPP currently provides for twice-annual purchases at a discount of at least 15% to the market price, subject to certain limitations.

Inventions and Non-Disclosure. You will be required to sign the Inventions and Non­ Disclosure Agreement, attached to this letter, as a condition of your employment.

Restrictive Covenants, Trade Secrets and Confidential Information from Current or Prior Employers. You agree that you will not bring or use any confidential information or trade secrets from current or former employers during your employment with the Company. You have notified the Company of any and all non-compete, non-solicitation, confidentiality or other agreements with your current or former employers that could impact your employment with the Company and, prior to your start date, you will provide the Company with copies of

such agreements. You also agree that you have reviewed the duties and responsibilities of your new position and that no contractual or other restrictions will prevent you from performing those duties.

Authorization to Work. Federal law requires that you provide the Company with the legally required proof of your identity and authorization to work in the United States. We will furnish you with a list of acceptable documents. This documentation must be provided within three (3) business days of the date your employment begins, or our employment relationship with you may be terminated.

At-Will; Entire Agreement. Your employment is at-will and for no specified period, and either you or the Company may terminate this employment relationship at anytime and for any reason. This Agreement, including the enclosures, contains our complete, final, and exclusive agreement relating to the terms and conditions of your employment, and supersedes all prior or contemporaneous oral or written agreements, representations, or discussions. This Agreement cannot be amended or modified except by a written instrument signed by you and the Chief Executive Officer of the Company.